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Home My WebLink AboutAPA2744APRIL 1985 DOCUMENT No.2744 FINAL REPORT FISH RESOURCES AND HABITATS IN THE MIDDLE SUSITNA RIVER TECHNICAL REPORT No.1 rnl~~=~~~@©@ ITNA JOINT VENTURE ER CONTRACT TO FEDERAL ENERGY REGULATORY COMMISSION PROJECT No.1114 SUSITNA HYDROELECTRIC PROJECT ·:l·••.·,··,;/:I,NSTREAM FLOW RELATIONSHIPS REPORT SERIES '::l····.···••··\;WtJODWARD-CL YDe CONSULTANTS ~~ALASKA POWER AUTHORITY_---.;l - SUSITNA HYDROELECTRIC PROJECT Document No.2744 Susitna File No.4.3.1.4 -rK \4:JS- \se f"'-("1;;l. VLO I ~lLJq - ,.... - -- INSTREAM FLOW RELATIONSHIPS REPORT SERIES FISH RESOURCES AND HABITATS IN THE MIDDLE SUSITNA RIVER TECHNICAL REPORT NO.1 Prepared by Woodward-Clyde Consultants Entrix Under Contract To Harza-Ebasco Susitna Joint Venture Prepared for Alaska Power Authority Final Report April 1985 ARLIS Alaska Resources .'C"C'LIbrary &Imonrw.tlOn."ervlces Anchorage,Alaska ~, .~ The primary author of this report is T.R.Jennings.The draft version of this:report was prepared while he was an employee of Woodward-Clyde Cons:ultants.The final version was prepared while an employee of Entrix, Inc.,under contract to Woodward-Clyde Consultants • L, .- I""-eo-N-.::t-.::t 0 0 """0 I LD LDr--- ('I') ~('I') _____L i~ _____IT --~~~----.....-----.,.....----~~~~--------------~~- - ...., - Thi.s report represents a volume of the Instream Flow Relationships study technical report series prepared for the Sus,itna Hydroelectric Proj ect.The primary purpose of the Ins,tream Flow Relationships Report and its associated technical report series is to present technical information and data that reflect the relative importance of the various interactions amc:ng the primary physical and biolog;cal components of aquatic habitats within the Talkeetna-to-Devil Canyon reach of the Sus,itna River.The Instream Flow Relationships Report and its associated technical report series are not intended to be an impact assessment.However,these reports present a variety of natural and with-project relationships tha~provide a quantitative basis to compare alternative streamf.low regimes, conduct impact analyses,and prepare mitigation plans. The technical report series is based on the data and findings presented in a variety of baseline data reports p~epared by the Alaska Department of Fish and Game (ADF&G)SU Hydro Aquatic study Team,R&M ConsuJ.tants,E.Woody Trihey and Associates (EWT&A)and the Arctic Environmental Information and Data Center (AEIDC).The Instream Flow Relationships Report and its associated technical report series provide the methodology and appropriate technical information for use by those deciding how best to operate the proposed Susitna Hydroelectric Project for the benefit of both power production and downstream fish resources.The technical report series is described below. Technical Report No.1.Fish Resources and Habitats in the Middle Susitna River.This report,prepared by Entrix,In,::. and woodward-Clyde Consultants,consolidates information on the fish resources and habitats in the Talkeetna-to-Oevil Canyon reach of the Susitna River available through January 1985 that is currently dispersed'throughout numerous reports. iii - - ,.... - - Tec:hnical Report No.2.Physical Processes Report.This report,being prepared by Harza-Ebasco and R&M Consultants, des,cribes such physical processes as:reservoir sedimentation, cha,nnel stability and groundwater upwelling. Technical Report No.3.Water Quality/Limnology Report.This report,being prepared by Harza-Ebasco,consolidates existing information on water quality in the Susitna Basin and provides technical discussions of the potential for with-project bioaccumulation of mercury,influences on nitrogen gas supersaturation,changes in downstream nutrients,and changes in turbidity and suspended sediments.A draft report based principally on data and information that were available through June 1984 was prepared in November 1984. Technical Report No.4.Instream Temperature.This report, pr~pared by AEIOC,consists of three principal components:(1) ins'tream temperature modeling:(2)development of temperature cri'teria for Susitna River fish stocks by species and life I stalge;and (3)evaluation of the influences of with-project stream temperatures on existing fish habitats and natural ice processes.A final report describing downstream temperatures ass10ciated with various reservoir operating scenarios and an evaluation of these stream.temperatures on fish was prepared in Octlober 1984.A draft report addressing the influence of anticipated with-project stream temperatures on natural ice prol::esses was prepared in November 1984. Tech.nical Report NO.5.Aquatic Habitat Report.This report, beililg prepared by EWT&A,describes the availability of various typ4as of aquatic habitat in the Talkeetna-to-oevil Canyon river reach as a function of mainstem discharge.A preliminary draft of 'this report is scheduled for March 1985 with a draft final repl:lrt prepared in FY86. iv - .-. - - .- .- Technical Report No.6.Ice Processes Report.This report being prepared by AEIDC,Harza-Ebasco,and R&M Consultants will describe naturally occurring ice processes in the middle river, anticipated changes in those processes due to project construction and operation,and discuss the ~ffects of nablrally occurring and with-project ice conditions on fish habitat. v TABLE OF CONTENTS -PREFACE • LIs'r OF FIGURES •••iii viii LIs'r OF TABLES xi 1.0 INTRODUCTION •1 2.0 BACKGROUND ••3 9 9 9 12 15 15 20 20 23 23 30 30 30 30 31 31 31 • •3.4 3.3 3.1 3.2 INTRODUCTION TO FISH RESOURCES • • OVERVIEW OF IMPORTANT SPECIES • CONTRIBUTION TO COMMERCIAL FISHERY 3.2.1 sockeye Salmon. 3.2.2 Chum Salmon 3.2.3 Coho Salmon 3.2.4 Pink Salmon 3.2.5 Chinook Salmon • SPORT FISHING • 3.3.1 Arctic Graylinq 3.3.2 Rainbow Trout 3.3.3 pink Salmon 3.3.4 Coho Salmon 3.3.5 Chinook Salmon. 3.3.6 Chum Salmon 3.3.7 Sockeye Salmon •• SUBSISTENCE FISHING • 3.0 - 4.0 SPECIES BIOLOGY 4.1 ADULT SALMON 4.1.1 Sockeye Salmon. 4.1.2 Chum Salmon 4.1.3 Coho Salmon 4.1.4 Pink Salmon 4.1.5 Chinook Salmon. 4.2 INCUBATION 4.2.1 Dissolved Oxyqen • 4.2.2 Temperature 4.2.3 Substrate 4.2.4 Streamflow. 4.2.5 Superimposition 4.2.6 Predators 4.3 JUVENILE SALMON. 4.3.1 Sockeye Salmon. 4.3.2 Chum Salmon 4.3.3 Coho Salmon 4.3.4 Pink Salmon 4.3.5 Chinook Salmon. 4.4 RESIDENT SPECIES 4.4.1 Rainbow Trout • •. 32 32 32 43 57 63 72 82 84 86 90 91 92 93 93 93 99 104 109 113 118 118 vi TABLE OF CONTENTS (continued) 5.0 SUMMARY OF HABITAT UTILIZATION ••••••••••• 5•1 MAINSTEM AND SIDE CHANNEL HABITATS • • • • • • 5.1.1 Adult Salmon •••••••••••••• 5.1.2 Juvenile Salmon •••••••••••• 5.1.3 Resident Species •••••••••••• 5.2 SIDE SLOUGH AND UPLAND SLOUGH HABITATS •• 5.2.1 Adult Salmon.• • • • • • ••••• 5.2.2 Juvenile Salmon • • • • • • • • • • • • 5.2.3 Resident Species •••••••••• 5.3 TRIBUTARY AND TRIBUTARY MOUTH HABITATS •• 5.3.1 Adult Salmon.• • • • • • • •••• 5.3.2 Juvenile Salmon •••••••• 5.3.3 Resident Species • ••••••• 4,4.2 Arctic Grayling ••••·• • • • •·• 4,4.3 Burbot •• • ••·• • • •·•·•·4.5 OTHER SPECIES .· ······ · · · · ···4,5.1 Round Whitefish ···· · ····· ··4,5.2 Longnose Sucker ··· · ··· · · · ··4,5.3 Humpback Whitefish · ··•· · ···4.5.4 Dolly Varden •· ·····•······4,5.5 Arctic Lamprey · ······· · · ·4.5.6 Threespine stickleback · · · ····4.5.7 Bering cisco •·· · ·····•··4.5.8 Eulachon · ··· · · · · ········4.5.9 Sculpin ······•· · · · ·4.5.10 Lake Trout · · · · · •·····4,5.11 Northern pike •· · · •·•····4.5.12 Ninespine Stickleback ······· ·· - .... """. ,...., 6.0 FACTORS AFFECTING PRODUCTION • 6 •1 ADULT SALMON • • • • • 6.2 SPAWNING AND INCUBATION • 6 • 3 REARING.• • • • • • • • ·. .. ... . .· . ... . . . . .· ... ...· .... . ... . . 119 120 121 121 122 123 123 123 124 124 124 125 125 125 126 127 127 127 129 130 131 132 133 134 135 135 136 137 139 139 140 144 · ... . . . . . . . . . . . . ADF&G SUSITNA HYDRO REFERENCE LIST IN ClmONOLOGlCAL ORDER • • • • • • - - - i ,- AClmOWLEDGEMENTS LITJl:RATURE CITED APPll:NDIX A. ..· . . · . ..· .. · . . . . 147 148 156 - - - LIST OF FIGURES Page Figure 1.Susitna River drainage basin.· · ·····4 Figure 2.General habitat categories of the Susitna River -a conceptual diagram.·······5 Figure 3.Upper Cook Inlet commercial salmon management area...··· ················11 Figure 4.Commercial catch of upper Cook Inlet salmon, 1954-1983.··· ····· ··· · ···· · · 13 Figure 5.Commercial catch of upper Cook Inlet sockeye, 1954-1983.············ · · ····17 Figure 6.Commercial catch of upper Cook Inlet chum, 1954-1983 · ·· · ······ · · ·····18 Figure 7.Commercial catch of upper Cook Inlet coho, 1954-1983 ·· · · ··· ····· ··· ··19 Figure 8.Commercial catch of upper Cook Inlet pink, 1954-1983 ············ ··· ··21 Fi~tre 9.Commercial catch of upper Cook Inlet chinook, I1954-1983 ·· ······· ··········22 Figure 10.susitna River and major tributaries from mouth to Sheep Creek.······· ····· · 27 Figulre 12.Migrational timing of second-run sockeye salmon based on fishwheel catch per unit effort at selected locations on the Susitna River in 1981,1982 and 1983 • • • • • • • • • •34 - Fiql.lLre 11.Susitna River and major tributaries from Sheep Creek to Devil Canyon • • • • • • •·..28 Figu.re 13.Comparison of second-run sockeye fishwheel catch and mainstem discharge at Sunshine station (RM 80)1981-1983 ••••••••••••35 F igu.re 14.Migrational timing of ("'hum salmon based on ~fishwheel catch per unit effort at selected locations on the Susitna River in 1981,1982 and 1983 . . . . . . . . . . . . . . . . . . . .45 Figure 15.Comparison of chum salmon fishwheel catch and mainstem discharge at Sunshine station (RM 80), "1981-1983.• • • • • • • • • • • • • • • • • • •47 viii LIST OF FIGURES (continued) .... Fig:ure 16. Fig'ure 17. Migrational timing of coho salmon based on fishwheel catch per unit effort at selected locations on the Susitna River in 1981,1982 and 1983 • • • • • • • •.'• • • • • • • • . • •58 Comparison of coho salmon fishwheel catch and mainstem discharge at Sunshine station (RM 80),1981-1983 • • • • • • • • ••• • • • •59 ,~, - Figure 18.Migrational timing of pink salmon based on fishwheel catch per unit effort at selected locations on the Susitna River in 1981,1982 and 1983 • • • • • • • • • • • • • • • •••65 Figure 19.Comparison of pink salmon fishwheel catch and mainstem discharge at Sunshine Station,(RM 80), 1981-1983 ••••••••••••••••••••66 Figure 20.Migrational timing of chinook salmon based on fishwheel catch per unit effort at selected locations on the Susitna River in 1981,1982 and 1983 • • • • • • • • • • • • •••• ••• •74 Figure 21.Comparison of chinook salmon fishwheel catch and mainstem discharge at Sunshine Station, (RM 80),1981-1983 • • • • • • • ••• •••76 Fiqure 22.Chum salmon spawning time versus mean Iincubationtemperaturenomograph• • •. ...•89 Fiqure 23.Distribution of juvenile sockeye salmon by macrohabitat type on the Susitna River between the Chulitna River confluence and Devil Canyon, May through October 1983.Percentages are based on mean catch per cell ••• • • ••• • •95 ~Figure 24.Chum salmon fry daily catch per hour recorded at the downstream migrant traps,May 18 through August 20,1983 and sockeye salmon fry daily -catch per hour recorded at the downstream migrant traps,May 18 through August 30,1983 ••97 Figure 25.Distribution of juvenile chum salmon by macrohabitat type on the Susitna River between the Chulitna River confluence and Devil Canyon, May through October 1983.Percentages are based on mean catch per cell ••••••••••101 Figure 26.Coho salmon age 0+and age 1+or older daily catch per hour recorded at the downstream migrant traps,May 18 through August 30,1983 •105 ix I~ - --I LIST OF FIGURES (continued) Figure 27.Distribution of juvenile coho salmon by macrohabitat type on the Susitna River between the Chulitna River confluence and Devil Canyon, May through November 1983.Percentages are based on mean catch per cell • • • • • • •••106 Figure 28.Pink salmon fry daily catch per hC"lr recorded at the downstream migrant traps,May 18 through July 8,1983 • • • • • • • • • • • • • • •111 Fi~lre 29.Distribution of juvenile chinook salmon by macrohabitat type on the Susitna River between the Chulitna River confluence and Devil Canyon, May through November 1983.Percentages are based on mean catch per cell ••••••••••115 Fi~lre 30.Chinook salmon age 0+and age 1+daily catch per hour recorded at the downstream migrant traps,May 18 through August 30,1983 • • • • •117 x LIST OF TABLES Common and scientific names of fish species observed in the Susitna Basin • • • • • • • . .10 Commercial catch of upper Cook Inlet Salmon in numbers of fish by species,1954-1984.•14 Summary of commercial and sport harvests on Susitna River basin adult salmon returns.•16 29· . . susitna Basin sport fish harvest and effort by fishery and species -1978, 1979, 1980, 1981,1982 and 1983 • • • • • • • • • • • •24 sport fish harvest for Southcentral Alaska and Susitna Basin in numbers of fish by species,1978-1983.• • • • • •••• Average salmon escapements in the Susitna River by species and location • • • •· . . 36 Second-run sockeye salmon peak survey counts in sloughs upstream of RM 98.6,1981- 1984.. . . . . . . . . ....·...· . . . 39 Second-run sockeye salmon total slough escapement upstream of RM 98.6,1981-1984 40 Sex ratios of second-run sockeye at F1athorn,susitna,Yentna,Sunshine, Talkeetna and CUrry stations,1981- 1984 . . . . . • . . . . . . . •44 Table 10.Chum salmon peak index counts by habitat type upstream of RM 98.6,1981-1984 •••·. . . 49 ..... Table 11.Chum salmon peak index counts in sloughs upstream of RM 98.6,1981-1984 · · · ···.50 Table 12.Chum salmon total slough escapement upstream of RM 98.6,1981-1984 .•..•.·· · •·..51 Table 13.Chum salmon peak index counts in streams upstream of RM 98.6,1981-1984 ·····52 Table 14.Chum salmon peak spawner counts in mainstem habitats upstream of RM 98.6,1981-1.984.··54 xi __,_._~"''''f·---------------------- Table 15. Table 16. Table 1',. Table 18. LIST OF TABLES (continued) Sex ratios of chum salmon at F1athorn, Susitna,Yentna,Sunshine,Talkeetna and CUrry Stations,1981-1984 •••••••• Coho salmon peak index counts in streams upstream of RM 98.6,1981-1984 ••••• Sex ratios of coho salmon at F1athorn, Susitna,Yentna,Sunshine,Talkeetna and Curry stations,1981-1984 •••••••• Pink salmon peak index counts in streams upstream of RM 98.6,1981-1984 ••••• · . . 56 62 64 69 Table 19.Pink salmon total slough escapement upstream of RM 98.6,1981-1984 •••••••••••••71 Table 20. Table 21. Table 22. Table 23. Sex ratios of pink salmon at Flathorn, susitna,Yentna,Sunshine,Talkeetna and Curry stations,1981-1984 •••••••• Chinook salmon peak survey escapement counts of Susitna River streams by sub- basin from 1976 to 1984 ••••••••• Chinook salmon peak index counts in streams upstream of RM 98.6,1981-1984 • Sex ratios of chinook salmon at Yentna, Sunshine,Talkeetna and curry stations, 1981-1984 •••••••••••••••• xii · . . · . . · . . 73 77 80 83 -I r ! - 1.0 INTRODUCTION Thif;report summarizes the available information on the fishery res()urces and habitats of the Susitna River,with emphasis on the river reach between Talkeetna and Devil Canyon.It is basE~d primarily on existing reports and analyses generated by the feasibility and licensing studies of the Susitna Hydroelectric Project,with a lesser dependence on additional pert:inent information in the literature.The objective of the repc)rt is to synthesize and summarize information to describe the biology,relative abundance and seasonal habitat utilization of important fishery resources.As a part of the Inst:ream Flow Relationships (IFR)report series,information sunmlarized here will assist in defining the relationships bet":l7een physical processes and fishery habitat in the Susitna RivE~r basin. Since the report series provides important information relative to t~edecision making process,this report focus~s on habitats and species most likely to be affected by the proposed project. Most:of the report emphasizes the Ta1keetna-to-Devi1 Canyon reac:h [river mile (RM)98.6-152]of the Susitna River.This rivElr reach extends from the proposed Devil Canyon dam site (RM 152)downstream to the confluence of the Susitna and Chulitna rivElrs (RM 98.6).Effects on habitats downstream of the proposed project are expected to be greatest within this reach. DOWIllstream from Talkeetna,the inflow from the Talkeetna and Chulitna rivers is expected to reduce the magnitude of changes in physical processes under with-project conditions. This,report emphasizes salmon and important resident species, and their habitat utilization.section 2.0 contains a brief description of the proj ect and proj ect area and a summary of the studies that have been conducted to date on the fish resources.In Section 3.0 the species of the Susitna River are introduced and their commercial,recreational and subsistence 1 I .i utilization and importance are discussed.Section 4.0 sUltlIl1larizes information on the species biology of the fish in the Susitna River.Habitat utilization by species/life stages is summarized in Section 5.0.Section 6.0 discusses some fact,ors that may affect fish production in freshwater and th';~ Susitna River drainage. 2 ,~ 2.0 BACKGROUND The Susitna River flows approximately 318 miles (530 km)and drains about 19,600 square miles (50,900 km2 )from the terminus of the Susitna Glacier in the Alaska MO\,"'ltain Range to Cook InlE~t (Figure 1).The study area for the Susitna Hydroelectric pro:ject includes the Susitna River mainstem,side channels, sloughs,and tributaries.A diagram and description o··f habitat catE~gories of the Susitna River is presented in Figure 2. The Alaska Power Authority (APA)has proposed construction of two dams on the Susitna River:Watana Dam (RM 184)and Devil Can~{on Dam (RM 152).The proj ect would reduce streamflows during the summer and increase them during the winter. Suspended sediment levels,turbidity and water temperatures are expE~cted to follow similar patterns (reduced levels in summer and increased levels in winter).Details of dam construction, opeJ::,ation and expected changes to aquatic habitats and fish resc)urces were presented by Acres American (19S3a,b)in the FedE!ral Energy Regulatory Commission (FERC)license applica- tion.Additional studies and analyses have since taken place that:further refine and update the license application.Any quefations concerning the license application and studies in support of the application should be directed to the APA. Beginning in 1974,detailed studies were conducted to describe and quantify fish resources,aquatic habitats and habitat utilization in the Susitna River.In 1980 the Susitna HydJ:,oelectric Proj ect Aquatic Studies Program was initiated and funded by the APA.Baseline data collection by ADF&G SU Hydro on fish and aquatic habitat resources was divided in.to three groups:Adult Anadromous Fish Studies (AA),Juvenile Anadromous and Resident Fish Studies (RJ),and Aquatic Habitat and Ins1~ream Flow Studies (AH). 3 J J 1 J 1 ')1 J J i -1 -1 »1 ] '/ 'I'I "---------------",'"y -'\ /\ /'~.\ ....•"I_1 J I, I ~I I I I (\ \~~\\-11#~\;\,, o \,, o J "--------,,'""",,"""""....,_:.",,,'-- It••°e!!!!!!!!~"5;iiiiiiiiii·...... .. "" ~"'''''''."-............. @ --"~...,---~ lOWfll OllAINAG£lI"'IN " ... / I I I I I I I I I,- '"'"'"'"SUSITNA "I\lfll '" IlflAIPfAGf:IIA$lPf ~'" ...." ",.... -'...... 0#'"...'... ..."LOWEll ORAIPfAGf:... '"'"'",- I I I I \,/.J ,'".,~,-\ /''\ I I I,,, I I, I I, \ \~-.\..,...., ,I'"~""...'"""..."'--'"",, \ \ \ \ "'" SUSITNA RIVER DRAINAGE BASIN. ALASKA POWER AUTHORITV SUSITNA HVDROELECTRIC PROJECT FIGURE 1 Woodward-Clyde Consultants and ENTAIX,INC. HARZA-E8ASCO SUSITNA JOINT VENTURE )]-1 1 -])J I ]1 )))1 j ! I r CEIlEAAt IIABITAI CAIEGORIES Of TilE SUSIIHA RIVER I lJ1 I) 21 lJ 4) 51 6) 1) ".tnU.-H.blt.t conshn of those portio'"of tht SUlttn.tlnr thlt no""",11YCOiiViYstrr.llflow IhnulfjhlJf,ll the yf.r,Both stngl,,nd ....lttple ch,nnel relChu In!!Indudrd In thh h.btl.t ul'901'")'_GroundNUer Ind tributary Inflow .ppe....to be tncon'Sequrnll.l contributor'S tq the o",r.1f rh.rlclerhtlu of ..,,,n,.hlblht.",tMI~h.Mill h trplul1y ch.r.clrl"lud by htqh "'.ter vfloclllf~.nd "'ell If1IlOred 'Strf.ll'l:Jfd~. SYbll ....t ..,9'ner.lly Cf'nltst of bovldfl!r tnd cohbh'sin IUtertih wtth 'nhn,lttl.1 SPiCes.tilled yUh I groul-Itl:c "hture of 'Nil gr.veh 'nd gl.eI.,".nds.SusP4!!nded sedtN!nl concenlrilions .nd turbidity Irt:htgh during 'SUllll'fr due to the Infl",nu of·gl.cI.,Ilflt-v.hr.Strf'II'low~ ",.c.de I.,.ul,fill Ind the IIW!IMt ..cleus .pprectlbty In Oct~r.An tce cuwer fo...'M the-river ~n I.U NowHltler or DecMer. Side Ch.nn.1 H.blt.t con,hh b'th(}~.por,l.,ns of tMo Susttn.'her thu nnl"Wlll1y conve,,rt••lIIHow durln9 tt~e open ",.ter ",uon but bl!CIJlhf' .pprecl.b1r dewllerll!d dudn9 pt'l'lods or low f1,*,.Sid.ch.npel h.edul ...)'eJlht eUher tn ~n deftn.d OurfllN'ch.nnel-.,or In poorl,defined vlt"r cour,n flowing through p.rtlilly s",b..rged 9rnel bus .nd hhl'ds .101H)the 1Nt"91nS 01 the Nln~tfll river.Stet.ch.nnel Ure.lllbed fle~ w.tton,....typ'tally 'ower th.n the ••n IIIOnt~lr wiler surhee ele- wltlons 01 the ...tnstHt Su,ttn'Rhi..-observed during June.Julr .nd Aulj"U,S'd~ch.nne1 h.bltlts Ire thUlClertred by ,h.II(l1l1j1er depth. IOWf"r w"ocltles ."d ,...11.r stre.med ..,.Ierlah th.n the .dJu.nl h.blt.t of the IIIIlnstHi rhpr. f~!-~~u~,H:~J!fto~:p,~~~·t:~dl~hesP~~~,:::;r~~:~~~~~~'I~b:flW;~: SUslln.Rher and Is usu.lI,,ep.rlled IrM Ihe ...In,t...nd tot. ch.n".h hr wIT wef4et.UIf blrs.-."eJlPtlsI'd .ll"wl.1 b.,.ortfn Ifparlle,th~h..'n'I~sloo9h '1'011I ...tn,t..(lr sldf chlnroel l1ows. The controlling slre."lb@d/UrPIII'la.n"e1eWltlons II the upun••end of the 'Ide slough\'r.sTtljh\I,Ins thin the ",.ltr surhce flevUt.,."0' the "'n ftInt~ly flows of the _In,th'Su.ltn.River flttsff"ved for June. Jul,.Illd Au«)l.lsi.At tnte,...dl ..le .nd low.tlow period,.th.,Itt.,Inuljh, tonw"d.,r ••ter fro-s...11 trlbutartes ."d/ur up""ltlnIJ '1rOllnd'wllfr (AOfIG 19Ah:.19A1b).Thtlf cI"1'.lter Inflows lire ruen,•••cop~ trthutors tq the ...lst.t1e.01 this h.hltat typt'.,,,,."'attr sur flu e'entlotl of the Sus"t1.River vener.lly (lust,•blC.wllfr to ..t.nd ...11 uP Into the SlbUg"fro-ItS lbW@r .nd (MFIG 19ftlc.1962bl.hen ~~~~r~y t~~:,:~~tarlt..I:"~~(I\v:tt::a.'~~~tt~t~~d '~~:~:I f~:~~~::~::~'~; th.,Iough ch.nn,,1 oll'n connys w.l.r tndtp."Hnl of ..Inst..b.dwaler '''eth.At hhJh flows the w.t,r surllC",ttv.tlon of the ....'nst8 rhfr IS suHlclent tn OW'l'tbP tht'uppt'r end of the sloogh (AOFlG 1981c. IgU2b).Surht;e viler ..-.".fr.tures In IN!sid.slOU9h'during '........r llli'Inths .re prll1clpalt,•funcllon of ..Ir tlNlpfrllur••'ohr rd,.Hon • •nd th.t~r.tln'·'of the loul .runoft. ~=:i~:.~I::tor'fhlfh~t,~~~fersS-~~c-:n:::(~~:c.'~lr!ilh~·~hl.t·:ur~c~h~~I:~ of ttle INlnstlrM Susttn.Rher or ttl ,Ide'chlnl1ph.lhe".,Ioughs Ire ch.rlCt.rtttd b,thf'presence 01 b,ner dl.s .nd .n ,(cu"-,htlo"of ~tli cowfrl"g th.-,substrlle ",suiting fro-th.IbSI't1te of ...Instll!:.iCoortng t1ClWS. ~MtC~i;:lt'~~;:tl~~;S\~~St ~(u~hl!ln'''tlh~~~~~~r~~s.of 1~~~~,u;~~so~:1 ,tru.f).,..sedl"'nt.Ind tht,...1 I"Pg'.':tflfCt the Inlrgrathm or IN! h,droTnl)Y.9'blog,.Ind dill"'.01 the tributary draln'~'Ih.phrsll:.1 .ttrlbuteS 01 trlbullry h.blt.t '1'"not MPfndPnt on ...lnstHt condltlnl1'. }H~~~;~i'6~t~-¥t1~;:st~tn:,s :r:rt::~~:;~~c~:~~~rlnflt::[ttt::I;~: d....nstr•••e.tel11 of th.tributary P'UIIll!!dIlch uteflds Inlo Ihe ...lnHell Su,It".River or slough fA8FAIi .1}8Ic.19R1b). l.ke H.bll.t co",ht~of wlrlous l~nllC enwtronll)l!nts that OCCur within ~~uHrn.RI"er draln.ge.these hllbUlls nng.Ir(Jlll s..H.,h.II~, hohtfd hkf..perchftd on th.tundr"to 1."1'1".deepfr hkn IIIIhlch conned In the ...Ih\l~5I.t,Un.RIv~r through lIIIell defined tributary s,sl,.S.the labs r,uhf their lIf.t.r Ir(Jlll ,prtngs.surhc:e runoff .nd/or lrlbuhrl.s. ALASKA POWER AUTHORITY SUSITN~HYDROELECTRIC PROJECT GENERAL HABITAT CATEGORIES OF THE SUSITNA RIVER - A CONCEPTUAL DIAGRAM (SOURCE:AEIDC.MODIFIED BY ADF&G 1982e.), FIGURE 2 Woodward·Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE - - - The objectives of the three groups of this continuing program are: (1)AA -determine the seasonal distribution and relative abundance of adult anadromous fish populations produced within the Susitna River drainage; (2)RJ -determine the seasonal distribution and relative abundance of selected resident and juvenile anadromous fish populations within the Susitna River drainage;and (3)AH -characterize the seasonal habitat requirements of selected anadromous and resident fish species within the Susitna River drainage. A summary of the significant accomplishments to date by the threle sections of ADF&G's Su Hydro Group is outlined below. Adult Anadromous a.Documented migrational timing of salmon runs in the Susitna River. b.Estimated population size and relative abundance of salmon in sub-basins of the Susitna River. c.Estimated total slough escapements for salmon in sloughs upstream of RM 98.6. d.Estimated relative abundance of spawning salmon in tributaries upstream of RM 98.6. 6 e.Quantified selected biological characteristics for salmon stocks in the Susitna River (i.e.sex ratio, fecundity,age and length). -f.Determined migrational timing,relative abundance,sex ratio,age composition and length of eulachon. g.Documented migrational timing of Bering cisco. Resident and Juvenile Anadromous a. b. c. d. e. Estimated population size for Arctic grayling populations in the proposed impoundment areas. Identified important spawning areas for selected resident species. Estimated the relative utilization of macrohabitat types for juvenile salmon and selected resident species. Developed habitat suitability criteria for juvenile salmon and selected resident species. Estimated population size and survival for juvenile chum and sockeye. f.Defined outmigration timing for juvenile salmon. ~ ~atic Habitat and Instream Flow a.Collected physical and chemical water quality data describing macrohabitat types. b.Identified aquatic macrohabitat types within the middle reach of the Susitna River (RM 98.6 -152). 7 """ c. d. e. Defined seasonal timing and utilization of adult salmon in macrohabitat types. Developed site-specific habitat responses to mainstem discharge. Developed habitat criteria for adult and juvenile salmon,eUlachon,Bering cisco,and selected resident species. .- """ - f.Evaluated the passage of adult salmon into selected sloughs. g.Confirmed the importance of ground water upwelling for spawning salmon in sloughs • For a list of ADF&G Susitna Hydro references,see Appendix A. 8 ,...., - - 3.0 INTRODUCTION TO FISH RESOURCES 3.1 OVERVIEW OF IMPORTANT SPECIES Fishery resources in the Susitna River comprise a major portion of the Cook Inlet commercial salmon harvest and provide fishing opportunities for sport anglers.Anadromous species that form the base of these fisheries include five species of Pacific sal:mon:chinook,coho,chum,sockeye and pink.Other anadromous species present in the Susitna River include eulachon and Bering cisco. The Susitna River is a migrational corridor,spawning area and juvenile rearing area for the five species of salmon from its poi:nt of discharge into Cook Inlet (RM 0)to Devil Canyon (RM 152),where salmon are usually prevented from moving upstream by a high velocity barrier.Sloughs and tributaries provide most.of the spawning habitat for salmon,while the mainstem, SlO'Llghs,and tributary mouths are important I habitats for juv1enile salmon rearing and overwintering (Barrett et ale 1984, Sch:midt et ale 1984). Imp10rtant resident species found in the Susitna River basin include Arctic grayling,rainbow trout,lake trout,burbot, Dolly Varden and round whitefish.Scientific and common names of all fish species observed in the Susitna River basin are lis'ted in Table 1. 3.2 CONTRIBUTION TO COMMERCIAL FISHERY With the exception of sockeye and chinook salmon,the majority of the upper Cook Inlet commercial catch of salmon originates in the Susitna Basin (Barrett et ale 1984).The upper Cook Inl~~t area is that portion of Cook Inlet north of Anchor Point and Chinitna Bay (Figure 3).The -long-term average annual catc::h of 3.o.million fish is worth approximately $17.9 million in 1984 dollars to the commercial fishery (K.Florey,ADF&G, 9 TabIEa 1.common ani scientific names of fish species observed in the SUsitna Basin. '"'"" - """ scientific Name PetrtJmyZontidae I.ampetra japonica Salnr:mi.dae CoregorlUS laurettae Core:101lUS pidschian oncorhynchus goibusc:ha oncorhmchus keta oncorhYnchus kisutch oncorhynchus nerka oncortlynchus tshaWYtscha Prosopium cylil'ldraceum Salmo gairdneri Salve1inus ma1Ina Salve1inus namaycush 'lhymallus arcticus Osmeridae 'IhaleichtAYs pacificus Esocldae Esox lucius catoe~tomidae castostomus catostomus Gadidae rota Iota GastEu:osteidae Gasterosteus acu1eatus ~rPungitius pungitius Cottidae eottus sp. common Name Arctic lamprey Bering'cisco humpback whitefish pink salm:m chum salm:m coho salmon sockeye salmon chinook salmon round whitefish rainbow trout Dolly Varden lake trout Arctic grayling eulachon northern pike lon;nose sucker threespine stickleback ninespine stickleback sculpin ,.,.. - Sourc:e:ADF&G 1981a,b;1982a;1983b;Barrett at ale 1984;schmidt at al. 1984;Sautner and stratton 1984. *Unpublished data,ADF&G SU Hydro,Anchorage,Alaska. 10 )-1 I J i ]1 J ]J J 1 1 J 1 )1 J I(ASILO,.". I<WOA.....OTH...urn............:e-'~"~-" i f;,j ''';'''''•.-'",,;;;::.....:;"'".y.:,......_/..'J I _••, '../'.,., CHUTNA It.•jv...../\...."'-"//" '.'I CHAKACHAT 'y'/1 ,-'NA R.NORTHtltN V (ANCHQRAO[ ...AltT....":.:.................-...-'""'V"OIST"ler /•••A,TURNAGAIN '\... IeUITATAN It.J /..,\..ARM."'-"\...-."'.."/.,.-..../'''-'\........... OM ',\.,"--"n •.'."'\....-'..\ ",/...;J "'.r Cf ,.lAST ..... )/NT""l •,.ORlLAND ••'Ollr,,1CT ~ I J ('i C"fSCfNT ,,'>i t-....T......"/..A ..•..•Uy~..·.J.···)'\\~;'\'1- )~/ :'/ /C[HT"Al Dlsr"ler ... c ..'I HlH,TN"",,-•••..../:"~")! .("NCHOft ,.T.. l-' l-' UPPER COOK INLET COMMERCIAL SALMON MANAGEMENT AREA ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 3 Woodward-Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUS"NA JOINT VENTURE perE;.comm.1984).In recent years commercial fishermen have landed record numbers of salmon in the upper Cook Inlet fishery (Fi~rure 4);over 6.·7 million salmon were caught in 1983 and over 6.2 million fish in 1984.The Susitna River is the most impclrtant salmon-producing system in upper Cook InL.::t (ADF&G 198:i:a;Barrett et ale 1984,1985);however,the quantitative cont:ribution of the Susitna River to the commercial fishery can onlji'be approximated because of: o the high number of intra-drainage spawning and rearing areas; o the lack of data on other known and suspected salmon-producing systems in upper Cook Inlet; o the lack of stock separation programs (except for sockeye salmon);and o overlap in the migration timing of mixed stocks and species in the Cook Inlet harvest areas. r- , The:refore,the estimates of contributions of Susitna River salnton to the upper Cook Inlet fishery should be viewed as app:roximations. 3.2.1 Sockeye Salmon The most important species in the upper Cook Inlet commercial fishery is sockeye salmon.In 1984,the total sockeye harvest of :a.1 million fish was valued at $13.5 million (K.Florey, ADF&:G,pers.comm.1984).The commercial sockeye harvest has averaged 1.34 million fish annually in upper Cook Inlet for the last 30 years (Table 2).The estimated contribution of Susitna Rive:r sockeye to the commercial fishery is between 10 to 30 perc:ent (Barrett et al.1984).This represents an estimated annu.al commercial harvest of between 134,000 to 402,000 Susitna Rive:r sockeye over the last 30 years.In 1983,Susitna River 12 8---------------------------, 6 .....(".C) C) C).. C) C) C)..4...,..,.. 2:....... :::I: ~(,) to· c:I~ (;) 2 1985198019751970196519601955 O...---.....--......----r----....---..,r-----,.----l 1950 YEAR COMMERCIAL CATCH OF UPPER COOK INLET SALMON,1954-1983. ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT -FIGURE 4 Woodward-Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE 13 --------------- - Table 2.cannnercial catch of upper COok Inlet sa1Jnon in numbers of fish by species,1954 -1984. 14 -- .- soc}~eye contributed approximately 500,000 fish to the total catch of 5 million (Table 3).The 1983 commercial sockeye catch was the highest in 30 years of record (Figure 5). 3.2 ..2 Chum Salmon ChUIlI\salmon and coho salmon are about equal in importance in the upper Cook Inlet commercial fishery and rank second and third in value after sockeye (K.Florey,ADF&G,pers.comm. 1984)•The upper Cook Inlet chum salmon catch has averaged 659 j'000 fish annually since 1954 (Table 2).The contribution of Susitna River chum to the upper Cook Inlet fishery is about 85 percent (Barrett et a1.1984).This contribution represents an lastimated annual chum harvest of 560,000 Susitna River fish in the commercial harvest over the last 30 years./In 1982,the SusJLtna River contributed approximately 1.21 million fish (Table 3)of the record harvest of 1.43 million chum salmon takem in the upper Cook Inlet fishery (Table 2:Figure 6).In 198~~,the total chum salmon harvest of 684,000 fish in the c01111l1ercia1 fishery was valued at $2.0 million (K.Florey, ADF~iG,pers.comm.1984). 3.2.3 Coho Salmon since 1.954,the upper Cook Inlet coho salmon commercial catch has averaged 264,000 fish annually (Table 2).Approximately 50 percent of the commercial coho harvest in upper Cook Inlet is frollt the Susitna River (Barrett et a1.1.984)•This cont:ribution represents an average annual Susitna River coho hanrest of 132,000 fish in the commercial fishery over the last 30 years.In 1982,the Susitna T~iver contributed an estimated 388,.500 fish (Table 3)to a record harvest of 777,000 coho takem by the upper Cook Inlet fishery (Figure 7).In 1984,the totcL1 coho salmon harvest of 443,000 fish in upper Cook Inlet had a worth of $1.8 million (K.Florey,ADF&G,pers.comm. 1.98~',)• 15 1 I J 1 1 ]]]1 J ,J .~ Table 3.Summary of commercial and sport harvests on Susitna River basin adult salmon returns. Commercial Harvest Sport Harvest Upper Estimated Estimated Estimated Susistna Cook Inlit Estimated susitna Susitna Total Basin sPzrt Percent of 2SpeciesHarvestPercentSusitna Harvest Escapement Run Harvest Escapement - sockeye Mean Range 3811,443,000 20 (10-30)288,600 287,0003 575,t/00 1,283 0.4 82 3,237,000 20 (10-30)647,400 279,0003 926,400 2,205 0.8 83 5,003,000 10 (10·30)•500,300 185,0005 685,300 5,537 3.0 84 2,103,000 20 (10-30)420,600 605,800 1,026,400 Pink 381128,000 85 108,800 127,0003 235,800 8,660 6.8 82 789,000 85 670,650 1,318,0003 1,988,650 16,822 1.3 83 74,000 85 62,900 150,0005 212,900 4,656 3.1 84 623,000 85 529,550 3,629,900 4,159,450 I-'Chum 3(J\81 843,000 85 716,550 297,0003 1,013,550 4,207 1.4 82 1,429,000 85 1,214,650 481,0003 1,695,650 6,843 1.4 83 1,124,000 85 955,400 290,0005 1,245,400 5,233 1.8 84 684,000 85 581,400 812,700 1,394,100 Coho 381494,000 50 247,000 68,0003 315,000 9,391 13.8 82 777,000 50 388,500 148,0003 536,500 16,664 11.3 83 521,000 50 260,500 45,0005 305,500 8,425 18.7 84 443,000 50 221,500 190,100 411,600 Chinook 81 11,500 -1,150 7,57610---_.- 82 20,600 10 2,060 -....-10,521 83 20,400 10 2,040 ....--12,4206848,800 10 880 250,000 251,000 ---------------------------------- 12 Source:ADF&G Commercial Fisheries Division . 3 B.Barrett,ADF&G Su Hydro,February 15,1984 Uorkshop PresentatIon 5%for chumYentnastation+Sunshine Station estimated escapement +5%for sockeye,+48%for pink,+ 4 +.85%for coho (Source:B.Barrett,ADF&G SU Hydro,February 15,1984 Yorkshop Presentation). 5 MIlls 1982,1983,1984 6 flathorn Station (RM 22)Escapements (Barrett et ala 1985) Source:Barrett et ala 1985 - 8 ......-----------------------., 5 -ena 0 0 0 . 0 0-1 0 30.... z """'"-'-% CJ 2I- ~<CJ ~1 198519801955 O'....---...----..,----r----....--.....,r----~---_1 1950 YEAR COMMERCIAL CATCH OF UPPER COOK INLET SOCKEYE;1954-1983. ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 5 Woodward-Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE 17------------------------------------_._--------- 2_------------------------........ 1.S..... en. c:::» c:::» c:::».. e:::» c:::» c:::»..,--,.1-Ill.-...... :lC (,)....( (,) 0.5 1985198019751970 YEAR 19601955 Ol ....---~--...,---..,.---.....--....,r__--...,.---""I 1950- COMMERCIAL CATCH OF UPPER COOK INLET CHUM.1954-1983. ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 6 Woodward·Clyde Consultants and ENTRIX,INC•. HARZA-EBASCO SUSITNA JOINT VENTURE 18 ,--_.~-----,--~--------------------------------------- - 80·----------------------------, 71J- 60,-,-en 50 0 0 0 . 0 P'"'.... Z--:: ~u... e( ·U 1985198019751970196519601955 O...----------....---.....----.r-----r-----l 1950 YEAR COMMERCIAL CATCH OF UPPER COOK INLET COHO,1954-1983. ~, ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 7 Woodward.Clyde Consultants and ENTRIX,INC. HARZA-ESASCO SUSITNA ·JOINT VENTURE 19 ,~ 3.2.4 Pink Salmon Pin:!t salmon is the least valued of the commercial species in upplar Cook Inlet.The upper Cook Inlet average annual odd-year har~est of'pink salmon since 1954 is about 120,000 fish,with a ranc~e of 12,500 to 544,000 fish.The average annual even-year har~est is approximately 1.58 million pink salmon with a range of 0.48 to 3.23 million fish (Table 2;Figure 8).The estimated contribution of Susi'l:.na River pink salmon to the uppler Cook Inlet pink fishery is 85 percent (Barrett et ale 198'~)•This represents an average annual Susitna River con1:ribution of 0.10 million odd-year and 1.34 million even-year pink salmon to the upper Cook Inlet fishery over the las1:30 years.In 1984,the total pink salmon harvest of 623 II 000 fish in upper Cook Inlet was worth an estimated $0.5 million (K.Florey,ADF&G,pers.comm..1984). 3.2,,5 Chinook Salmon ..... The commercial chinook harvest has averaged 19,200 fish annually in the upper Cook Inlet fishery over the last 30 years (Tahle 2;Figure 9).Since 1964,the opening date of the conunercial fishery has been June 25.The Susitna River chinook run begins in late May and peaks in mid-June.Thus,by June 25 the maj ority of chinook have already passed through the area sub:ject to commercial fishing.Catches of chinook salmon have aveJ:aged 11,600 fish annually for the 20"year period of 1964-1983.Approximately,10 percent of the total chinook ha~,est in upper Cook Inlet are Susitna River fish (Barrett et ale 1984).This represents an average annual contribution of 1,960 chinook to the upper Cook Inlet fishery for the last 30 yeaJ:s,or 1,160 fish for 1964-1983.In 1984,the 8,800 chinook cau~Jht in the upper Cook Inlet fishery were valued at $0.3 million (K.Florey,ADF&G,pers.comm.1984). 20 ,-----~,--------------@--...,...----""!"'""---~---------------- 1985198019751970196519601955 oJ,..--.....::::::=::;;;;::===;===::;~--...--.=..,._-=-~ 1950 3 EVEN-YEAf~-en. 0 0 ~ 0 0 ~,.. Z 2--2: (,) ~.-C (,) --1 YEAR COMMERCIAL CATCH OF UPPER COO~K INLET PINK,1954-1983. -ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE B Woodward-Clyde!Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE 21 70_---------------------------, """'"60 -en. 0 O' ~ ~... Z-30-: ~(,) l-e (,) 20.- ,~ 6 10 1985197019601955 0··001I---.,....--...,.---r---.,-----r---,..----t 1960-YEAR COMMERCIAL CATCH OF UPPER COOK INLET CHINOOK,1954-1983. - ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 9 Woodward-Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE 22 '-------------------......,---_.-._------_. ~, - - - 3.3 SPORT FISHING Increases in population and tourism in Alaska have resulted in a growing demand for recreational fishing.Recreational fishing is now consi(ered a significant factor in total fisheries management,particularly in Cook Inlet where commercial and non-commercial user c(:mflicts have developed (Mills 1980).The Susitna River and its major salmon and resident fish-producing tributary streams provide a multi-species sport fishery.Since 1978,the drainage has accounted for an average of 127,100 angler days of sport fishing effort,which·is approximately 9 percent of the 1977-1983 average of 1.4 million total angler days for Alaska and 13 percent of the 1977-1983 average of 1.0 million total angler days for the Southcentral region (Mills 1979,1980, 1981,1982,1983,1984). The sport fish harvests for 1978 throu~Jh 1983 from the Susitna Basin,based on mail surveys to a sample of lic:ense holders, are shown in Table 4 (Mills 1979,19810,1981,1982,1983 and 1984).The estimates represent the sport fishing harvests throughout the Susitna Basin and include an area that is larger than that which could be affected by the proposed project (see Figures 10 and 11 for locations of most of the major tributaries listed in Table 4). 3.3.1 Arctic Grayling The annual Arctic grayling sport harvest has averaged 18,200 fish in the Susitna Basin and 61,500 fish in Southcentral Alaska over the last six ye?rs (Table 5).The largest sport harvest of Arctic grayling on recorar in the Susitna Basin occurred in 1980 when an estimated 22,100 fish were caught. This represents about 32 percent of the total Southcentral Arctic grayling harvest in 1980 (Mills 1981). 23 1 ])1 1 l 1 ~~]1 J )l J -.1 )i 11Jj Table 4.Susitna Basin sport fish harvest and effort by fishery and species·1978.1979,1980. 1981.1982 and 1983. ------- Days Chinook Coho Sockeye Pink Chum Rainbow Dolly lake Arctic locations Fished Salmon Salmon Salmon Salmon Salmon Trout Varden Trout Grayl i ng Burbot 1978 Willow Creek 22,682 47 905 56 18,901 2,458 913 280 0 208 9 Caswell Creek ... Montana Creek 25,762 408 2,451 85 15,619 4,429 1,193 633 0 958 9 Sunshine Creek .-. Clear (Chunilna)Creek 5,040 12 2,200 28 2,074 1,912 1,501 1,817 0 859 27 Sheep Creek 11,869 256 478 14 6,981 1,697 470 108 0 461 18 little Willow Creek 5,687 0 151 28 3,142 1,015 334 63 0 334 0 DesHa River 9,111 850*1,798 0 697 0 3,634 0 0 579 0 lake Creek 8,767 326*2,212 254 2,833 1,015 2,721 154 36 2,115 45 Afexander Creek 6,914 769*2,401 183 1,146 215 2,640 136 0 1,871 0 Talachulitna River 732 12*88 141 31 234 0 235 0 99 0 lake louise,lake Susitna, Tyone River 13,161 0 0 0 0 0 0 0 2,522 2,278 2,947 Others 14.970 163 2,388 56 3.994 2,692 1.519 2,739 877 3,779 208 1978 Total 124,695 2,843 15,072 845 55,418 15,667 14,925 6,165 3,435 13,532 3,263 --------- 1979 . willow Creek 18,911 459 462 94 3,445 582 1,500 6i8 0 1,654 18 Caswell Creek 3,710 156 624 0 100 9 282 91 0 354 0 Montana Creek 22,621 312 1,735 346 2,472 745 1,536 527 0 791 9 Sunshine Creek 3,317 10*774 157 700 55 382 264 0 0 45 Clear (Chunilna)Creek 5,125 312 1,248 31 645 355 1,373 827 0 1,045 9 Sheep Creek 6,728 10 462 31 2,418 682 573 127 0 645 64 little Willow Creek 5,171 0 262 141 745 118 345 336 0 1,091 0 Deshka River 13,236 2,811 973 0 109 0 3,182 0 0 1,463 82 Lake Creek 13,881 1,796 2,671 1,40 882 136 4,527 164 9 1,963 109 Alexander Creek 8,284 712 1,560 79 236 45 1,182 182 0 745 145 Talachulitna River 2,185 293 125 47 100 55 0 155 0 664 45 lake louise,lake Susitna, Tyone River 12,199 0 0 0 0 0 0 0 2,618 2,936 2,363 Others 12,639 39 1,997 220.______.664 1,245 3,472 909 472 4,918 282 1979 Total 128,007 6,910 12,893 1,586 12,516 4,072 18,354 4,200 3,099 13,342 3,171 ------------------- *Chinook less than 20 inches J -)J }---1 1 OJ B J I J -)I ~)J ) Table 4.(Continued) -------~------------------------------------------------------------------------~----------------------------------------------------------------------- Days Chinook Coho Sockeye Pink Chum Rainbow Dolly Lake Arctic Locations Fished Salmon Salmon Salmon Salmon Salmon Trout Varden Trout Grayling Burbot -------_.............-------------------- 1980 Wi llow Creek 29,011 289 1,207-83 23,638 989 1,168 636 0 1,868 0 Caswell Creek 4,963 215 1,124 77 1,663 19 154 83 0 353 26 Montana Creek 19,287 559 2,684 257 8,230 571 854 167 0 655 13 Sunshine Creek 5,208 132 1,534 116 2,408 225 193 39 0 0 39 Clear (Chunilna)Creek 4,388 172 661 6 622 385 950 751 0 1,348 32 Sheep Creek 8,041 45*430 9 6,362 648 385 83 0 725 45 Little Willow Creek 8,190 32*494 77 6,420 270 353 122 0 1,156 0 Deshka River 19,364 3,685 2,290 0 689 0 4,305 0 0 1,817 224 Lake Creek 8,325 775 2,351 267 2,101 69 2,144 121 9 1,972 0 Alexander Creek 6,812 1,438 999 52 809 121 1,945 353 0 1,145 0 Talachulitna River 2,542 121 491 112 276 17 379 982 0 1,713 0 Lake Louise,Lake Susitna, Tyone River 10,539 0 0 0 0 0 0 0 2,609 4,477 6,612 Others 12,216 45*2,234 257 3,403 1.445 2.651'790 267 4,854 212 1980 Total 138,886 7,389 16,499 1,304 56,621 4,759 15,488 4,127 2,876 22,083 7,203 --------- N ------ lJ1 Days Chinook Chinook Coho sockeye Pink Chum Rainbow Dolly Lake Arctic Locations Fished Salmon*Salmon Salmon Salmon Salmon Salmon Trout Varden Trout Grayl ing Burbot ----..... 1981 Willow Creek 14,060 144 441 747 77 2,797 1,533 1,475 249 0 1,188 48 Caswell Creek 3,860 77 172 901 38 335 0 326 38 0 144 0 Montana Creek 16,657 239 422 2,261 182 1,782 805 1,111 240 0 891 0 Sunshine Creek 3,062 57 0 968 220 958 125 249 10 0 57 115 Clear (Chunilna)Creek 3,584 86 287 422 29 19 57 1,226 1,418 il 996 0 Sheep Creek 6,936 0 0 326 105 1,236 987 201 57 0 872 0 Little Willow Creek 3,845 0 0 29 _67 604 192 374 48 0 623 0 Deshka River 13,248 738 2,031 632 0 19 0 3,631 10 0 1,255 96 Lake Creek 6,471 163 632 1,035 211 412 48 2,874 67 19 1,600 29 Alexander Creek 6,892 278 843 891 67 57 10 2,290 287 0 1,130 29 Talachulitna River 1,378 57 0 240 172 29 0 0 0 0 479 0 Lake Louise,Lake Susitna, Tyone River 14,397 0 0 0 0 0 0 0 0 4,093 4,892 5,292 Others 7,850 277 0 939 115 412 450 3,851 814 287 7,089 57 1981 Total 102,240 2,748 4,828 9,391 1,283 8,660 4,207 13,757 3,238 4,399 21,216 5,666 --------------------------------------- *Chinook less than 20 inches. J -,1 ))J )1 J ]J ~J )I J Table 4.(Continued) ----------------------------------------------------------~-----------------~------------~------------------------------------------------------------- Days Chinook Chinook Coho Sockeye Pink Chum Rainbow Dolly Lake Arctic Locations Fished Salmon*Salmon Salmon Salmon Salmon Salmon Trout Varden Trout Grayl ing Burbot --- 1982 Uillow Creek 19,704 220 409 1,069 94 4,789 2,086 891 262 0 1,520 63 Caswell Creek 5,101 178 293 776 52 1,092 0 189 73 0 252 0 Montana Creek 23,645 126 115 3,060 514 3,595 1,708 2,243 356 0 849 0 Sunshine Creek 3,787 52 0 1,719 189 1,132 231 545 42 0 42 73 Clear (Chunilna)Creek 3,856 52 398 996 115 220 31 608 1,069 0 943 0 Sheep Creek 9,093 0 0 367 88 2,599 1,750 325 409 0 723 0 Little Uillow Creek 5,579 0 0 398 105 1,520 199 335 189 0 377 0 Deshka River 18,391 1,142 3,165 2,463 0 377 0 3,804 0 0 1,457 252 Lake Creek 8,649 356 1,289 1,603 252 398 199 3,134 482 0 1,955 0 Alexander Creek 10,748 681 1,825 1,907 335 482 0 2,505 42 0 1,582 84 Talachulitna River 1,911 0 0 524 63 220 0 0 31 0 587 0 Lake Louise,Lake susitna, Tyone River 14,024 0 0 0 0 \0 0 0 0 4,056 3,532 5,565 others 9,980 220 0 1,782 398 398 639 2,400 1,666 335 5,041 63 1982 Total 134,468 3,027 7,494 16,664 2,205 16,822 6,843 16,979 4,621 4,391 18,860 6,100 IV 19830'1 Uillow Creek 13,405 136 398 576 425 1,647 1,490 1,689 336 0 1,794 21 Caswell Creek 5,048 10 262 408 151 126 0 231 157 0 315 31 Montana Creek 17,109 199 305 1,402 534 902 1,311 1,332 325 0 336 0 Sunshine Creek 3,429 105 0 722 685 241 42 178 84 0 31 367 Clear (Chunilna)Creek 7,564 252 682 836 534 73 650 1,836 1,962 0 1,553 84 Sheep Creek 6,237 0 0 596 370 682 902 409 52 0 839 10 Little Uillow Creek 2,791 0 0 52 110 157 147 514 73 0 84 0 Deshka River 23,174 934 3,955 1,036 0 21 0 2,434 0 0 1,280 126 Lake Creek 14,749 535 1,888 1,392 726 430 52 2,287 262 0 2,224 283 Alexander Creek 9,425 672 1,039 408 69 126 0 608 136 0 483 0 Talachulitna River 4,556 63 273 84 41 0 0 0 105 0 3,178 0 Kashwitna River 1,344 231 0 52 0 0 0 357 304 0 514 0 Lake Louise,Lake Susits~Q Tyone River 12,948 0 0 0 0 0 0 0 0 3,210 4,217 4,070 Others 12,367 303 178 861 1,892 251 639 4,625 1.Q67 287 3,387 534 1983 Total 134,156 3,440 8,980 8,425 5,537 4,656 5,233 16,500 4,863 3,497 20,235 5,526 --------------------- *Chinook less than 20 inches Source:Mills (1979-1984) 15 Kilometers - -I - _. Flathorn Station (RM 22) __,;5:""'__-4\0 Miles o 5 10 COOK INLET SUSITNA RIVER AND MAJOR TRIBU1r ARIES FROM MOUTH TO SHEEP CREEK. "-'ANCHORAGE ...-.....~ "LASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 10 Woodward-Clyde Consultants and ENTRIX,INC. 27 HARZA-EBASCO SUSITNA JOINT VENTURE - - - - - - o SUSITNA RIVER AND MAJOR TRIBUTARIES FROM SHEEP CREEK TO DEVIL CANYON. At ASK A POW Efl AUT HORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 11 Woodward.Clyde Consultants and ENTRIX,INC. 28 HARZA-EBASCO SUSITNA JOINT VENTURE 1 J ]1 )J I )J .~]J j j 1 Table 5.Sport fish harvest for Southcentral Alaska and Susitna Basin in numbers of fish by species,1978-1983. ------------------- Arctic Grayling Rainbow Trout Pink Salmon Coho Salmon Chinook Salmon Chum Salmon Sockeye Salmon South-Susitna South-Susitna South-Susitna South-Susitna South-Susitna South·Susitna South-Susitna Year central Basin central Basin central Basin central Basin central Basin central Basin central Basin ----- 1978 47,866 13,532 107,243 14,925 143,483 55,418 81,990 15,072 26,415 2,843 23,755 15,667 118,299 845 1979 70,316 13,342 129,815 18,354 63,366 12,516 93,234 12,893 34,009 6,910 8,126 4,072 77,655 1,586 1980 69,462 22,083 126,686 15,488 153,794 56,621 127,958 16,499 24,155 77,389 8,660 4,759 105,914 1,304 1981 63,695 21,216 149,460 13,757 64,163 8,660 95,376 9,391 35,822 7,576 7,810 4,207 76,533 1,283 1982 60,972 18,860 142,579 16,979 105,961 16,822 136,153 16,664.46,266 10,521 13,497 6,843 128,015 2,205 1983 56,896 20,235 141,663 16,SOO 47,264 4,656 87,935 8,425 57,094 12,420 11,043 5,233 170,799 5,537 N \0 -------------------- Average 61,535 18,211 132,908 16,000 even-134,413 even-42,954 103,774 13,157 37,294 7,943 12,149 6,797 112,869 2,128 odd-S8,264 odd-8,611 Source:Mills (1979-1984) - .- 3.3.2 Rainbow Trout The Susitna Basin and Southcentral Alaska annual rainbow trout sport harvests have averaged 16,000 and 132,900 fish respectively since 1978 (Table 5).In 1979,about 18,350 rainbow trout were harvested by angler:;in the Susitna Basin, which represents approximately 14 percent of the Southcentral region rainbow trout sport catch in 1979 (Mills 1980). 3.3.3 Pink Salmon The annual even-year pink salmon sport harvest has averaged 42,950 fish in the Susitna Basin and 134,400 fish in Southcentral Alaska since 1978 (Table 5).The annual odd-year pink salmon sport catch has averaged 8 l'600 fish in the Susitna Basin and 58,300 fish in Southcentral Ji.laska since 1979 (Table 5).The largest sport harvest of pink salmon on record in the Susitna Basin occurred in 1980 when an estimated 56,600 fish were caught (Mills 1981).In 1981,the estimated,odd-year pink salmon sport harvest of 8,700 fish represented about 6.8 percent of the estimated Susitna esc2Lpement of 127,000 pink salmon (Table 3). 3.3.4 Coho Salmon Since 1978,the Susitna Basin and Southcentral Alaska annual coho .salmon sport harvests have averaged 13,200 and 103,800 fish respectively (Table 5).In 1982,about 16,664 coho were landed by anglers in the Susitna Basin.(Mills 1983),which is the largest annual catch on record.In 1983,almost one of every five coho entering the basin was caught b~sport anglers (Table 3). 3.3.5 Chinook Salmon The annual chinook salmon sport harvest has averaged 37,300 fish in Southcentral Alaska and 7,950 fish in the Susitna Basin 30 1= since 1978 (Table 5).This represents an annual Susitna Basin contribution of 21 percent to the Southcentral chinook sport harvest over the six year period.The largest Susitna Basin "..."sport harvest of chinook salmon on re!cord occurred in 1983, when 12,420 fish were caught by fishermen (Mills 1984). 3.3.6 Chum Salmon The Susitna Basin and Southcentral Ala,ska annual chum salmon sport harvests have averaged 6,800 and 12,150 fish respectively since 1978 (Table 5).The largest SPOL~catch of chum salmon on record in the Susitna Basin occurred in 1978 when 15,700 fish were landed (Mills 1979).For the years 1981 to 1983, chum salmon sport harvests have averaged between 1.4 and 1.8 percent of the estima~ed Susitna Basin chum salmon escapement (Table 3). 3.3.7 Sockeye Salmon ITheannualsockeyesalmonsportharvesthasaveraged 112,900 fish in Southcentral Alaska and 2,100 fish in the Susitna Basin for the years 1978 through 1983 (Table 5).In 1983 over 5,500 sockeye salmon were caught by fishermell in the Susitna Basin, which is the largest annual catch on record (Mills 1984).The sport catch of sockeye from 1981 through 1983 has averaged 3 percent or less of the estimated Susitna Basin sockeye escapement (Table 3). 3.4 SUBSISTENCE FISHING The only subsistence fishery on Susitna River fish stocks that is officially recognized and monitored by the Alaska Department of Fish and Game is near the village of Tyonek,approximately 30 miles (50 km)southwest of the Susitna River mouth.The Tyonek subsistence fishery was reopened in 1980 after being closed for sixteen years.From 1980 through 1983,the annual Tyonek subsistence harvest averaged 2,000 chinook,250 sockeye and 80 coho salmon (ADF&G 1984). 31 """' - ..... - 4.0 SPECIES BIOLOGY 4.1 ADULT SALMON Adult salmon escapements have be~n monitored at various sampling stations in the Susitna Basin.The locations of these stations are shown in Figures 10 and 11.The methodology used by ADF&G to monitor salmon escapements can be found in reports cited in the text. 4.1.1 sockeye Salmon (i)Timing of Runs Sockeye salmon enter the Susitna River in two distinct runs (Barrett et ale 1984,1985).The first,run of fish enters the river in late May to early June and passes Sunshine Station (RM 80)between the first and third weeks lof June (Barrett et ale 1984,1985).The escapement of first-run sockeye at Sunshine station was about 5,800 fish in 1982,3,300 fish in 1983 and 4,800 fish in 1984 (Barrett et ale 1984,1985).First-run sockeye spawn upstream of RM 80 in the l?apa Bear lake system in the Talkeetna River drainage (RM 97.1)(ADF&G 1982a,Barrett et ale 1984).Peak spawning activity in the Papa Bear Lake inlet stream was between the third week of July and the first week of August in 1982 and between the second and fourth weeks of July in 1983 and 1984 (ADF&G 1982a;Barrect et ale 1984,1985). Because first-run sockeye salmon spawn upstream of RM 80 exclusively in the Talkeetna River drainage,which will not be influenced by the project,they are nc)t discussed in further detail. Second-run sockeye enter the Susitna R.iver about the last of June.In 1981 through 1984 fish passed Sunshine station between the third week of JUly and the second week of August (Barrett et ale 1984,1985).These fish are abundant in the 32 -I I"'" mainstem of the Talkeetna-to-oevil Canyon reach (RM 98.6-152) from about the third week of July to the fourth week of August (Barrett et al.1984,1985).A summa~~of second-run sockeye migration timing in the Susitna River basin for 1981,1982 and 1983 is present9d in Figure 12. Second-run sockeye salmon migration timing is likely influenced by river discharge.In 1981 river discharge was declining from over 150,000 cfs when most second-run sockeye passed E~nshine Station (Figure 13).In 1982 a discharge spike above 80,000 cfs coincided with reduced AOF&G fishwheel catches (Figure 13). In 1983 river discharge was below 80,000 cfs at Sunshine station during most of the second-run sockeye migration and the run passed Sunshine station in one maj or peak (Figure 13). Based on this analysis,it appears that spikes in discharge over 100,000 cfs at Sunshine station can delay sockeye salmon migration timing. (ii)Escapement The total annual minimum escapement of second-run sockeye salmon in the Susitna River averaged 248,000 fish for 1981 through 1984 (Table 6).This estimate is considered a minimum because it is based on the summation of escapements at Sunshine and Yentna stations and does not include escapements downstream of RM 80,excluding the Yentna River (RM 28).In 1984, approximately 605,800 second-run sockeye reached Flathorn station (RM 22)(Barrett et al.1985).This estimate is based on data from the first year of monitoring at this location and does not include escapements downstream of RM 22 (Barrett et al.1985).Most second-run sockeye salmon spawn in tl~e Yentna (RM 28),Talkeetna (RM 97.1)and Chulitna (RM 98.6)drainages (Barrett et al.1984,1985). For 1981 through 1984,second-run sockeye escapements averaged 6,300 fish annually at Talkeetna station (RM 103)(Table 6), 33 ~J 1 )i I 1 i J 1 J ]I ~)j J l 1 J I , I I ..I •.'.'..I I 1883 S;~~~ciN i 1 r:r==f;:.I '1982 r-c.f:::::I I 1981 J..------------------------------------------- I I :....,;;;,:....:•.;~;......".'::'d ••••,f I 98 3 T:i:';~;Ai I E!::J'::.::::-::1 '1982 I 1·;:.:1·:I '1981 ~----_..._------------~..._----~---------------- M.dion PtOk Ront.\Coleh I /;:;:I ~;t:1 i /\ 00/0 Cumuloliv.95"1oCumuloth', Coleh 'If £rro.1 Caleh 1883 I E5:!J::..: ;I:>:::'~I 19821 ~I 1981'S;,W·~E::;·;;;:;I I '--SE-C-O-N-O-R-U-N--' SOCKEYE SALMON I 3 I I";.I';;;;u,,;.'1 I~88 _I:""':.'··..it.:;~.~<'.'..-.'-,.-...'_ 19821 E!:iI.i ...:,, 1981 I I i ::1:·::··::1 I I------------...------.........-------------------- Y£NTNA STATION - SUNSHINE STATIONw ",. 1 I 6/12 I I I I I I I I I I I I 6/26 7110 7124 -8/7 8/21 9/4 I I 9/18 DATE MIGRATIONAL TIMING OF SECOND-RUN SOCKEYE SALMON BASED ON FISHWHEEL CATCH PER UNIT EFFORT AT SELECTED LOCATIONS ON THE SUSITNA RIVER IN 1981.1982 AND 1983.(SOURCE:BARRETT et at.1984) ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 12 Woodward.Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSII NA JOINT VENTURE )I )1 )J 1 1 J J I I II1111 Alia •II HARZA-EBASCO SUSITNA JOINT VENTURE u11•JULy ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT Woodward·Clyde Consultants and ENTRIX,INC. I'!8HWHEEl CATCH (FC) DISCHARGE 10) FIGURE 13 COMPARISON OF SECOND-RUN SOCKEYE FISHWHEEL CATCH AND MAINSTEM DISCHARGE AT SUNSHINE STATION (RM 80), 1981-1983• 1. IE"T, IE"T, •II 1982 I11IIII AUG. ~,I,I, \ I, \, \,-'\/"......t,,,\,, ""," "\, I , ......-....,I ", ..",-..,.... ~;, ": I "",, ,I::,\.,"I,, \A : \ I JUly JUly I II)... ~ o 10 40 10 ,,.0 _'./,.,\~{:~~,,,,I~ o ,Ig~;,,,,.....' 24 'T' u... II;:z: % II)... 20+U10 180+-100 II, "1981 I I .~1983 I • I • I • 18-1 I ,I : 120 ,\f\~12 :~ "(i I'I ~,'. "I';'.:."I',"",'~I ,\I,_,'.,,, ..J I I ..J,I ' :::12 ..I I \,'"":::'.,I %..I ;;,..."\•5!I " ,%•\,'.1 ,,1, it." ,,"~g .....\/',",,01 " It .0 -,I "I,\•e "I \I •~iI I ""I)."\~iI '.,'-", "'." %.tf)',i WI '..I \1'"::s ,I I,'".. ....- ,,...."~0 ~..0,''\..a~\I \I) \ ,\II. U V ~....4'"........ '-..J '"'"%• w U1 J )J j I ]j 1 j 1 i )»J J 1 Table 6.Average sa1nK>n escapements in the SUSitna River by species ani location. r..ocationj sockeye1 Chmn2 Cd:102 Pink?arlnook4RiverMile Total yentrla station 126,750 21,200 19,600 odd 48,400 odd 215,950-RM 28,TRM 04 even 408,300 even 575,850 SUnshine station 121,650 431,000 43,900 odd 45,000 88,200 odd 729,750 RM 80 even 730,100 even 1,414,850 Talkeetna station 6,300 54,600 5,700 odd 5,900 16,700 odd 89,200 RM 103 even 125,500 even 208,800 w curry station 2,400 28,200 1,600 odd 3,300 13,000 odd 48,500 0'1 RM 120 even 87,900 even 133,lOO ~SUSitna 248,400 452,200 63,400 odd 93,400 odd 857,500-River even 1,138,400 even 1,902,500 1 Sacorn-run sockeye escapements.Four-year average of 1981,1982,1983 ani 1984 escapements. 2 Four-year average of 1981,1982,1983 ani 1984 ~pements. 3 Oid is average of 1981 am 1983 escapements.Even is average of 1982 am 1984 escapements. 4 'Ihree-year average of 1982,1983 ani 1984 escapements. 5 sununation of Yentna station am SUnshine Station average escapements.Does not include escapement to the susitna River ani its tributaries below RM 80 (excluding the Yentrla River)• Source:Barrett et ale 1984,1985 -with a range of 3,100 to 13,100 (Barrett et a1.1984,1985). These escapements are overestimates of the number of fish that spawn upstream of RM 103 because a significant number of fish return downstream of Talkeetna 'station (Barrett et a1.1984, 1985).In 1984,about 83 perc~~t of the sockeye escapement at Talkeetna station were milling fish that returned downstream to spawn (Barrett et a1.1985).If the 1984 escapement (13,100 fish)to Talkeetna station is reduced to account for this milling component of the run,spawning sockeye salmon in the Talkeetna-to-Devil Canyon reach accounted for about 0.5 percent of the 1984 second-run sockeye escapement to Flathorn station (Barrett et al.1985).In 1983 about 72 percent of the sockeye escapement to Talkeetna station (4,200 fish)were considered milling fish that returned downstream of Talkeetna station to spawn.The milling components of the sockeye escapements to Talkeetna Station were not estimated in 1981 or 1982. (iii)Migration Rate ..... I Tagged,second-run sockeye salmon migrated tne 23 miles between Sunshine Station (RM 80)and Talkeetna station (RM 103)at an average rate of travel of 4.6 miles per day (mpd)in 1981,2.7 mpd in 1982,2.4 mpd in 1983 and 5.8 ltnpd in 1984 (Barrett et al.1984,1985).The average rate of travel for tagged, second-run sockeye between Talkeetna Station and Curry station (RM 120)was:3.5 mpd in 1981,2.4mpd in 1982,3.0 mpd in 1983 and 8.5 mpd in 1984 (ADF&G 1981a,1982a;Barrett et al.1984, 1985)• (iv)Spawning Locations Almost all sockeye salmon in the Ta,lkeetna-to-Devi1 Canyon reach (RM 98.6-152)spawn in slough habitat (Barrett et al. 1984,1985).Relatively few sockeye spawn in the mainstem and tributaries.One main channel spawning site was identified during the 1983 survey and seven sites were located in 1984 37 - - (Barrett et al.1984,1985).The 1983 mainstem site (RM 138.6-138.9)was used by eleven spawning sockeye on September 15.Mainstem spawning sites were loca,ted between RM 131 and 142 in 1984.The peak count for all seven sites was 33 fish (Barrett et ~l.1985).About 50 percent of these fish were spawning in Side Channel 11 (RM 134.5-·135.3)(Barrett et al. 1985).six sockeye were observed in streams during the 1981 through 1984 surveys.However,all six were considering milling fish that did not spawn in streCims (ADF&G 19811:1,1982a, Barrett et al.1984).In 1984,13 sc)ckeye were observed in streams (Barrett et al.1985). During slough spawning surveys in 1981 through 1984,sockeye were observed in 23 sloughs upstream of RM 98.6 (Table 7). Three sloughs contained most of the fish in all four years. Sloughs 8A,11 and 21 accounted for 09 percent of the peak counts in 1981,95 percent in 1982,92 percent in 1983 and 88 percent in 1984 (Table 7). The peak of the sockeye spawning activity in sloughs occurred between the last week of August and the end of September in all four years (ADF&G 1981a,1982a;Barrett et al.1984,1985).A portion (24-44 percent)of the socke~re salmon monitored in sloughs in 1983 and 1984 did not spawn in the slough of first recorded entry (Barrett et al.1984,1985).These fish suffered mortality from either bear predation or stranding,or departed the slough and presumably spawned elsewhere (Barrett et al.1984). Total slough escapement of sockeye salmon upstream of RM 98.6 was estimated by calculati"lg the total fish days in slough habitat and then dividing by the averal:Je slough life (Barrett et al.1984,1985).The total slough escapement was about 2,200 fish in 1981,1,500 fish in 1982,1,100 fish in 1983 and 2,200 fish in 1984 (Table 8). 38 ---------_...........----------------,---------- Table 7.Seconi-run sockeye sa1lnon peak survey counts in sloughs upstream of RM 98.6,1981-1984. ~ Four-Year.-Slough River Mile 1981 1982 1983 1984 Average 1 99.6 0 0 0 10 3 2 100.2 0 0 0 7 2 3B 101.4 1 0 5 20 7 3A 101.9 7 0 0 11 5 ~5 107.6 0 0 0 1 0 6A 112.3 1 0 0 0 0 8 113.7 0 0 0 2 1 F'"8e 121.9 0 2 0 0 1 8B 122.2 0 5 0 1 2 Moose 123.5 0 8 22 8 10 '~SA 125.1 177 68 66 /128 110 B 126.3 0 8 2 9 5 9 128.3 10 5 2 6 6 9B 129.2 81 1 0 7 22....9A 133.8 2 1 1 0 1 10 133.8 0 0 1 0 0 11 135.3 893 456 248 I 564 540 15 137.2 0 0 0 1 0 17 138.9 6 0 6 16 7 19 139.7 23 0 5 11 10 20 140.1 2 0 0 0 1 21 141.1 38 53 197 122 103 22 144.5 0 0 0 2 1-Total 1,241 607 555 926 832 (1) ,.,- Source:ADF&G 1981a,1982a;Barrett et al.198;4,1985 (1)Four-year average of totals.... 39 Table 8.Second-ron sockeye salmon total slough escapement upstream of RM 98.6,1981-1984. Slough River MiJ.e 1981 1982 1983 1984 Four-Year Average 1 99.6 0 0 0 26 7 2 100.2 0 0 0 18 5 """"3B 101.4 0 0 10 36 12 3A 101.9 13 0 0 29 11 5 107.6 0 0 0 3 1-·8 113.7 0 0 0 5 1 8e 121.9 0 5 0 0 1 8B 122.2 0 13 0 0 3 Moose 123.5 0 20 31 0 13 SA 125.1 195 131 130 532 247 B 126.3 0 20 10 23 13 9 128.3 18 13 0 16 12 9B 129.2 212 0 0 18 58 9A 133.8 4 0 0 0 1 11 135.3 1,620 1,199 564 11,280 1,166-15 137.2 0 0 0 3 1 17 138.9 11 0 II 26 12 19 139.7 42 0 10 29 20 21 141.1 63 87 294 154 150-22 144.5 0 0 0 5 1 -Total 2,178 1,488 1,060 2,203 1,732 (1) Source:Barrett et ale 1984,1985 (1)Four-year average of totals 40 - ..... (v)Access The upstream passage of salmon into sloughs and side channels is dependent primarily on water depth and length of the passage reaches that are restrictive to the upstream :t'lovement of fish (Sautner et ale 1984).Hydraulic velocity barriers do not exist in the Talkeetna-to-Devil Canyon reach (RM 98.6-152) (Trihey 1982)•The mainstem discharge level directly influences passage into sloughs because of its influence on backwater at the mouths of sloughs and breaching at the upstream (head)ends of them.Under low mainstem discharge conditions (unbreached),the backwater at the mouths of sloughs and side channels may not be of sufficient depth to allow successful passage.As mainstem dis~charge increases,the backwater area generally increases in depth and extends its length upstream,which increases the depths within those reaches affected by the backwater.The elimination of passage restrictions within a reach by backwater inundation continues in the upstream direction with increasing mainstem discharge. When breaching occurs,depths become adequate for passage at all passage reaches in most sloughs and side channels (Sautner et al.1984). Mainstem discharge levels in the Susitna River at Gold Creek (RM 136.7)commonly range between 20,000 and 30,000 cfs during June,July and August when adult salmon are migrating upstream and 1s,ono to 20,000 cfs during peal<:spawning periods (20 August to 20 September)(Sautner et aJ...1984).Passage into sloughs varies considerably at a mainstem discharge level because of the diversity in the morphology of individual sloughs.Breaching of most sloughs in the Talke~tna-to-Devil Canyon reach (RM 98.6-152)occurs at relatively high mainstem discharges (19,000 to 42,000 cfs)(Sautner et al.1984). During the August 20 to september 20 period,mainstem discharge at Gold Creek is less than 15,000 cfs 50 percent of the time (Sautner et al.1984).Therefore,passage into sloughs and 41 - .- side channels is often controlled by the backwater at the slough mouth and the local flow from groundwater and runoff sources. Sloughs 8A,11 and 21 have a.;,;counted for over 90 percent of the sockeye salmon total peak counts in slough habitat (Table 7). At Slough 8A,successful passage conditions occur for all passage reaches when the northeast channel is overtopped at 33,000 cfs (Sautner et ale 1984).When the northwest channel breaches (27,000 cfs),the three lowermost reaches have successful passage conditions (Sautner et ale 1984).At lower mainstem discharges,Passage Reaches I and II have successful passage conditions due to backwater effects at mainstem discharges of 10,600 and 15,600 cfs,respectively (Sautner et ale 1984).Slough 11 is overtopped at a higher than normal mainstem discharge of 42,000 cfs (Sautner et ale 1984).Below breaching flows,the first three passage reaches have successful passage conditions at 16,200,33,200 and 39,600 cfs, respectively (Sautner et ale 1984).None of,the passage reaches in Slough 21 are influenced Joy backwater below the breaching discharge of the left fork (25,000 cfs)(Sautner et ale 1984).The local flows required for successful passage conditions at specific passage reaches have not been determined.Analyses are currently being done to determine these values in sloughs 8A,9,9A,11 and 21. (vi)Fecundity and Sex Ratio The mean fecundity for Susitna River second-run sockeye is 3,350 eggs per female (Barrett et ale 1984).This estimated fecundity is derived from the regressicm analysis of fecundity as a function of length and from the mean length of sockeye salmon measured at Sunshine station (Barrett et a1.1984). The average egg retention from a sample of 56 sockeye salmon was about 250 eggs per female in 1983 (Barrett et ale 1984). 42 - Almost 80 percent of the carcasses had retained 25 or fewer eggs,while only seven percent of the fish sampled had retained more than 1,000 eggs each.In 1984,the average egg retention was 64 eggs per female (Barrett et al.1985).Most fish examine ,1 (67 of 76 females)had completely spawned (Barrett et al.1985). The sex ratio (male to female)of second-run sockeye salmon in the Susitna River was 1.0:1 in 1981,1.2:1 in 1982,1.2:1 in 1983 and 1.0:1 in 1984 (ADF&G 1981a,1982a;Barrett et al. 1984,1985).Sex ratios varied considerably between some locations and years (Table 9).Sex ratj.os of sockeye salmon by age were reported by ADF&G (ADF&G 1981a,1982a;Barrett et al. 1984a,1985).Some males matured at an earlier age than females.Most returning adult sockeye were four or five year fish that had gone to sea after one year in freshwater (Barrett et al.1984,1985). 4.1.2 Chum Salmon (i)Timing of Run Chum salmon enter the Susitna River in late June to early July and are numerous in the lower river at Yentna Station (RM 28, TRM 04)by the third week of July (Barz'ett et al.1984,1985). The chum migration lasts about one month in the lower river, with most fish passing Yentna station,by the third \veek of August (Barrett et al.1984,1985).The migration passes Sunshine Station (RM 80)from the end of July to early September.In the Talkeetna-to-Devil Canyon reach (RN 98.F-152),the mi"gration begins about:the end of July and continues until the end of August.A summary of chum migration timing in the Susitna River for 1981,1982 and 1983 is presented in Figure 14. 43 Table 9.Sex ratios of second-nm sockeye at Flathom,SUsitna,yentna, SUnshine,Talkeetna and Cur:t:y statiorlS,1981-1984. ,- Sex ratio <M:F)1 location 1981 1982 1983 1984 Flathom station 1.5:1.....RM 22 susitna station 0.9:1 1.0:1 ,tt~RM 26 Yentna Station 1.2:1 2.1:1 1.5:1 0.9:1 RM 28,TRM 04 "'"' sunshine station 1.0:1 0.9:1 0.9:1 0.6:1 RM 80 f<J'ir~ Talkeetna station 0.6:1 1.3:1.1.6:1.0.6:1 RM 103 curry station 0.8:1 2.1:1.1.6:1.1.4:1 RM 1.20 SoUrce:ADF&G 1981a,1982a;Barrett et al.1984,1985 1·.Includes all aged and non-aged fish Dashes indicate no survey - 44 )J J 1 J ~B -j ))I I !J I 1 CURRY STATION- 18831 f//:;'f'ti ;Ut.i'f!:'TTl>,Pi !':·a f 18121 In::;t~~:\:':1 I 1881'IfP!x:,::;:,ld::::J I CHUM SALMON ...41..P•••It.,..\ColchHf?1;:i!:i:H /\ o%C~.'''.IO".e-ul.'''.Co'cll ,.r (no,.Colcll ,.r (/lor' ~ U1 TALKEETNA STATION "'I SUNSHINE.. STATION h ,~------------------------------------------ 18811 E:Ef ::(~lt!?:'r )1>!,i:=''';:'-1 , 18821 81:<;;:····\,I 188 I'EEti~':mIW5f.:!?t!#;S¥M I ~------~-~-------------------------------I P(:!::I',.'j"'::riu'::;:.:j1':i7.if '1881 I ns:;!;1ft..:;:'oil I t8 82 I Ii q ;'".t p;:;.t,;':I:...:::-S!':!:tj7]11881 ~--------~~-----------------------~--------- YENTNA STATION- •8/21 i Lii',;;!:?;:;:1 ;:!::'::eJi~!E\\!(t,';?'i i i Vii H:;<\t'j ?;'il ::'1 ai 'tel?',1882 I F?f=I ~-:jFeE?!h:ru :F3 Iltll • • t .-ttl t t t .----,I I 1/11 7/18 8/2 -8118 8/50 8/11 DATE r- 8/27 MIGRATIONAL TIMING OF CHUM SALMON BASED ON FISHWHEEL CATCH PER UNIT EFFORT AT SELECTED LOCATIONS ON THE SUSITNA RIVER IN 1981,1982 AND 1983.(SOURCE:BARRETT et al.1984)•ALASKA POWER AUTHOHITV SUSITNA HYDROELECTRIC PROJECT FIGURE 14 Woodward.Clyde Consultants and ENTRIX.INC. HARZA-EBASCO SUSITNA JOINT VENTURE -- ..... Chum salmon migration timing is likely influenced by river discharge (Barrett et ale 1984).Peak river discharge levels of 100,000 cfs or greater at Sunshine Station in 1981 and 1983 coincided with reduced fishwheel catches at Sunshine Station and apparently delayed upstream movement (Figure 15). (ii)Escapement For the last four years,the chum salmon minimum escapement in the Sus i tna River has averaged 452,20 Or fish (Tabl e 6).This estimate is considered a minimum because it is based on the summation of escapements at Sunshine and Yentna stations and does not include escapements downstream of RM 80,excluding the Yentna River (RM 28).In 1984,about 812,700 chum salmon reached Flathorn station (RM 22)(Barrett et ale 1985).This estimate can be considered the total Susitna River chum escapement because spawning downstream of RM 22 is minimal (Barrett et a1.1985).Most chum salmon spawn in the Talkeetna River drainage (RM 97.1)(Barrett et aID 1985). The annual chum salmon escapement for 1981 through 1984 aver- aged 54,600 fish at Talkeetna station (RM 103)(Table 6),with a range of 20,800 to 98,200 (Barrett et ale 1984,1985).These escapements overestimate the number of fish that spawn upstream of RM 103 because a significant portion of the escapement returns downstream of Talkeetna statio!'l.(Barrett et ale 1984, 1985)•In 1984,about 75 percent of the chum escapement to Talkeetna Station returned downstream to spawn (Barrett et ale 1985)•If the 1984 escapement (98,200 fish)to Talkeetna Station is reduced to account for the milling factor,the Talkeetna-to-Oevil Cany~n reach account:ed for about 3 percent of the 1984 total Susitna River chum escapement of 812,700 fish (Barrett et a1.1985).The milling components of the chum escapements to Talkeetna station were not estimated in 1981, 1982,or 1983. 46 J )1 1 J )1 1 ]1 »]-..~i j I ] 1983 ,I f",,' JI , \ "I I ,I I I I I 'J I,,, I,, \ \ \, \., ", IEPT..lUI.Y ~20 '00 " .1 II " II 1981 18 I: II I , I'"I I HI I , I \ I I I •, I ,"I~10 I I I " I I, " 14 I,, ":\ I I,,I I :;t\I ~~-I I I ,..',I III 12 §J V....._-,I I I III ~"I " , ( :I;1"J oj I,,\I ~I \ g •I I I I I o •, V I It 1 10 ~,..,I %iii ,I I , ...\I i ,I ~I '"t I OJ ..."',I 0 I •;:U I I , I -I,-,\,I 0 \-'\u \ I I I .. I J I .....I,I r,_I ~.o I I \:V '0+180 130 1.:;... III •~ I:, II:1-10 ;[, ;[.....4 u 1-70... •10 ~ -J HARZA-EBASCO SUSITNA JOINT VENTURE ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT Woodward-Clyde Consultants and ENTRIX,INC.FIGURE 15 fWiWHEEL CATCH (FC) DISCHARGE (01 COMPARISON OF CHUM SALMON FISHWHEEL CATCH AND -MAINSTEM DISCHARGE AT SUNSHINE STATION (RM 80), 1981-1983. 11 IE"'. 1982 I, I I • I I ',,", -'-""I ., 'J •, '-I J. " ", I ,I I , I I : I ,~ I I , I II',I, I I,;~, • I ,,'en -.I \It , t'"\,/\,);;~r., I I\; '.' 0; 8 2 8 10 -' "'... ;[ I: It ;[ % '".. u.. (iii)Migration Rate .- - Tagged chum salmon migrated between Sunshine station (RM 80) and Talkeetna Station (RM 103)at an average rate of travel of 4.1 miles per day (mpd)in 1981,4.9 mpd in 1982,3.8 mpd in 1983 and 5.8 mpd in 1984 (Barrett et al.1984,1985).Chum salmon migrated between Talkeetna station and Curry station (RM 120)at the following rates:4.5 mpd in 1981,7.7 mpd in 1982, 6.3 mpd in"1983 and 8.5 mpd in 1984 (Bar'l:'ett et ale 1984, 1985). (iv)Spawning Locations Most chum salmon spawning in the Talkeetna-to-Devil Canyon reach occurs in either slough or tributary stream habitats.In 1983 peak index counts in stream and slough habitats were about equal,while in 1981,1982 and 1984 counts were higher in sloughs (Table 10)~ Chum salmon peak index counts in sloughs upstream o~RM 98.6 were:2,596 fish in 1981,2,244 fish in 1982,1,467 fish in 1983 and 7,556 fish in 1984 (Table 11).Ten sloughs were occupied by spawning chum salmon in all four years (Table 11). Five of the ten (sloughs 21,11,8A,9A and 9)accounted for over 70 percent of the chum salmon counted (Table 11). Total slough escapements of chum salmon in sloughs upstream of RM 98.6 were estimated by dividing the total fish days in slough habitat by the average slough life of chum salmon (Barrett et ale 1984,1985).The total slough escapement was about 4,500 fish in 1981,5,100 fish in 1982,2,950 fish in 1983 and 14,650 fish in 1984 (Table 12). Chum salmon peak index counts in streams upstream of RM 98.6 were:241 fish in 1981,1,737 fish in 1982,1,500 fish in 1983 and 3,814 fish in 1984 (Table 13).In 1981,Indian River, 48 - Table 10.Chum salmon peak index counts by habitat type upstream of RM 98.6, 1981-1984. Source:ADF&G 1981a,1982a;Barrett et al.1984,1985 1 Includes main channel and side channel habiuLts 2 Includes upland slough.and side slough habitats ~ 3 Four-year average of totals .- 49 -Table 11.Chum salmon peak irrlex counts in sloughs upstream of RM 98.6 I 1981-84. Four-Year Slough River Mile 1981 1982 1983 1984 Average r""" I 1 99.6 6 0 0 12 5 ~2 100.2 27 0 49 129 51 3B 101.4 0 0 3 56 15 3A 101.9 0 0 0 17 4 4 105.2 0 0 0 0 0 5 107.6 0 2 1 0 1 6 108.2 0 0 0 0 0 6A 112.3 11 2 6 0 5.....7 113.2 0 0 0 0 0 8 113.7 302 0 0 65 92 Bushrod 117.8 0 0 0 90 23 "...80 121.8 0 23 1 49 18 8e 121.9 0 48 4 121 43 8B 122.2 1 80 104 400 146 Moose 123.5 1~7 23 68 76 84 A'124.6 140 0 77 111 82 A 124.7 34 0 2 2 10 8A 125.1 620 336 37 917 478 ~"B 126.3 0 58 7 108 43 9 128.3 260 300 169 350 270 9B 129.2 90 5 0 73 42 9A 133.8 182 118 105 303 177~.10 133.8 0 2 1 36 10 11 135.3 411 459 238 1,586 674 12 135.4 0 0 0 0 0 13 135.9 4 0 4 22 8 14 135.9 0 0 0 1 0 15 137.2 1 1 2 100 26 16 137.3 3 0 0 15 5 17 138.9 38 21 90 66 54 18 139.1 0 0 0 11 3 19 139.7 3 0 3 45 13 20 140.0 14 30 63 280 97 21 141.1 274 736 319 2,354 921 22 144.5 0 0 114 151 66 2lA 145.3 8 0 0 10 5 Total 2,596 2,244 1,467 7,556 Source:ADF&G 1981a,1982a;l3aJ:rett et ale 1984,1985 1 Four-year average of totals 50 Table 12.Chum salmon total slough escapement upstream of RM 98.6,1981-1984 . .-Four-Year Slough River Mile 1981 1982 1983 1984 Average l$liI$\ 1 99.6 10 0 0 46 14 2 100.2 43 0 96 188 82 3B 101.4 0 0 0 109 27 6A 112.3 19 5 0 0 6 8 113.7 695 0 0 217 228 Bushrod 117.8 0 0 0 161 40 80 121.8 0 53 0 60 28 8e 121.9 0 108 8 207 81 8B 122.2 0 99 261 860 305 Moose 123.5 222 59 86 284 163 AI 124.6 200 0 155 217 143 A 124.7 81 0 4 8 23 SA 125.1 480 1,062 112 2,383 1,009 !"""B 126.3 0 104 14 168 72 9 128.3 368 603 430 304 426 9B 129.2 277 12 °132 105 ~10 133.8 0 0 0 90 23 9A 133.8 140 86 231 528 246 11 135.3 1,119 1,078 674 '3,418 1,572 13 135.9 7 0 8 16 8 14 135.9 0 0 0 4 1 15 137.2 0 0 4 67 18 16 137.3 5 0 0 20 6 17 138.9 135 23 166 204 132 18 139.1 0 0 0 42 11 19 139.7 5 0 6 102 28 20 140.0 24 28 103 329 121 21 141.1 657 1,737 481 4,245 1,780 22 144.5 0 0 105 187 73 21A 145.3 14 0 0 38 13 Total 4,501 5,057 2,944 14,634 Source:Barrett et al.1984,1985 1 Four-year average of totals 51 Table 13.Chum salmon peak irrlex counts in streams upstream of RM 98.6, 1981-84. River Four-Year stream Mile -1981 1982 _1983 1984 Average ~ Whiskers Creek 101.4 1 ~0 0 0 0.... Chase Creek 106.9 1 0 0 1 1 Lane Creek 113.6 76 -11 __6 31 31 Lower Mc:Ke:n.zie Creek 116.2 14 0 1 23 10 ~Little Portage Creek 117.7 0 31 0 18 12 Fifth of July Creek 123.7 0 1 6 2 2 Skull Creek 124.7 10 1 0 4 4 Shennan Creek 130.8 9 0 0 6 4 Fourth of July Creek 131.1 90 191 148 193 156 Indian River 138.6 40 1,346 811 2,247 1,111 Jack Long Creek 144.5 0 3 2 4 2 .-I Portage CreekI 148.9 0 153 526 1,285 491 Total 241 1,737 1,500 3,814 Source:ADF&G 1981a,1982a;Barrett et ale 1984,1985 1 Four-year ave::.."""\ge of totals 52 -Fourth of July Creek and Lane Creek accounted for 85 percent of the 241 chum salmon counted during peak surveys (Table 13).In 1982,1983 and 1984 over 95 percent of the chum salmon counted in streams were observed in Indian Rive:r,Fourth of July Creek and Portage Creek. Less than 10 percent of the peak surve)r counts of chum salmon used mainstem spawning areas in 1981 through 1984 (Table 10). Peak counts at mainstem spawning sites l"ere:16 fish in 1981, 550 fish in 1982,219 fish in 1983 and 1,266 fish in 1984 (Table 10).During 1981 through 1984,38 mainstem spawning sites were identified.Most of these were sites located during 1984.Three sites were used.in three or more of the four years (Table 14). Generally,the peak spawning activity of chum salmon occurred during the last week of August in streams and the first two weeks of september in sloughs and mainstem spawning sites in 1981 through 1984 (ADF&G 1981a,1982a ~Barrett I et al.1984, 1985). (v)Access Access and passage of salmon into tributaries is controlled by conditions at stream mouths.As the stage in the mainstem decreases,the tributary mouths may become perched above the river.That is,steep deltas may form.If these steep deltas were to remain under low mainstem conditions,the upstream -passage of fish into tributaries could be inhibited.Based on the analyses by R&M Consultants (1982),Trihey (1983)and Harza-Ebasco (1984),most tributaries ill the Talkeetna-to-Devil Canyon reach will adjust to lower mainstem flows without detrimental effects on fish access. Access and passage conditions into selected sloughs for chum salmon are similar to the conditions described for sockeye 53 ---~----------'-------------------------~_._------ 54 t~· salmon in section 4.l.l,v.Sloughs 8A,9,9A,11 and 21 have accounted for over two-thirds of the to'tal peak counts of chum salmon in slough habitats during 1981 through 1984 (Table 11). Breaching and backwater effects at sloughs 8A,11 and 21 have been mentioned previously (Section 4.1.1).At S..J.ough 9, breaching occurs at 16,000 cfs (Sautner et al.1984).Below the breaching discharge,Passage Reach I has successful passage conditions at a discharge less than 12,000 cfs (Sautner et al. 1984)•The breaching and backwater efjEects on passage condi- tions have not been evaluated at Slough 9A (Sautner et al. 1984). (vi)Fecundity and Sex Ratio - ~. The mean fecundity for Susitna River chum salmon is 2,850 eggs per female (Barrett et al.1984).This estimated fecundity is derived from the regression analysis of fecundity as a function of length and from the mean length of females sampled at Sunshine station (Barrett et al.1984). The egg retention of chum salmon was estimated in 1983 from sampling 229 female carcasses in 12 sloughs and one main channel spawning site between river miles 98.6 and 161 (Barrett et al.1984).The median retention lIras about 114 eggs per female (Barrett et al.1984).Almost 75 percent of the carcasses had retained 25 or fewer eggs,while less than four percent of the fish sampled had retained more than 1,000 eggs each (Barrett et al.1984).In 1984,the average egg retention for 215 fish was 463 eggs per female (Barrett et al.1985). Over 75 percent of the fish sampled had completed spawning (Barrett et al.1985). The sex ratio (male to female)ojE ch\lI[ll salmon in the Susitna River was 1.0:1 in 1981,1.1:1 in 1982,1.2:1 in 1983 and 1.2:1 in 1984 (ADF&G 1981a,1982a;Barrett et.al.1984,1985).Sex ratios varied between locations and years (Table 15).Sex 55 -Table 15.Sex ratios of chum salmon at Flatho:m,SUsitna,yentrJa,sunshine, Talkeetna and Curry stations,1981-1984. ,..., location!Sex ratio (M:Fl 1 ,-River Mile 1981 1982 1983 1984 Flatho:m station 1.1:1--RM 22 SUsitna Station 0.6:1 0.7:1-RM 26 yentna station 1.0:1 1.3:1 1.3:1 0.7:1 RM 28,mi 04- sunshine station 0.8:1 1.0:1 1.0:1 1.1:1 RM 80.- Talkeetna station 1.3:1 1.9:1 1.5:1 1.4:1 RM 103 ,.f,lllI'~ Curry station 1.1:1 1.1:1 1.9:1 2.0:1 RM 120 Source:ADF&G 1981a,1982a~Barrett et al.198'~,1985 .1 Includes all aged and non-aged fish Dashes i.niicate no survey 56 - - ratios by age are reported by ADF&G (ADF&G 1981a,1982a; Barrett et al.1984,1985).Most returning adult chum were four or five year old fish that had gone to sea during their first summer of life. 4.1.3 Coho Salmon (i)Timing of Run Coho salmon enter the susitna River about mid-July and are abundant in the lower river at Yentna station (RM 28,TRM 04) from the third week of July until the third week of August (Barrett et al.1984,1985).Coho salmon are numerous in the mainstem of the Talkeetna-to-Devil Canyon reach (RM 98.6-152) from the last week of July to the first week of September (Barrett et al.1984,1985).A summary of coho migration timing in the Susitna River for 1981,1982 and 1983 is presented in Figure 16. Coho salmon migration timing may bE~influenced by river discharge (Barrett et al.1984).In 1981 and 1983 discharge levels of 100,000 cfs or greater at Surlshine Station coincided with reduced fishwheel catches at Sunshine station and apparently delayed the upstream migration of coho salmon (Figure 17). (ii)Escapement - - The minimum coho salmon total escapement in the Susitna River basin has averaged 63,400 fish for 1981 through 1984 (Table 6). This estimate is based on the summa1:ion of escapements at Sunshine and Yentna stations and does not include escapements downstream of RM 80,excluding the Yentna River (RM 28).In 1984,about 190 ,laO coho salmon reached Flathorn station (RM 22)(Barrett et al.1985).This estima1:e is based on data from the first year of monitoring at this location and does not 57 1 )J 1 )J 1 J J 1 )1 )J 1 1 1 ,i CURRY ~ STATION TALKEETNA STATION - f--Mjj;jjitiif&iil.a;i;;;mai-t 1985 ~.i;;a 11882 ~=ii~11111 --------------------------~~----~-- I ERiiiSI_;;;;;&iii*ii3 11815 HiiiijiiiiiiMj,iiiiijJ 1"82 J---SmimmMi.Jii£,I,tiij:;'GI 11881 COHO SALMON ........,.,. ......\C.,~", ~/\ 8%C-ulollwe 'O-t.Culll"I.llw. Co'ch per Ellort Ctlch per £fforl 11l co SUNSHINE STATION ~ YENTNA ~ STATION ----~-------------~----------~-----~~ I E.-iflmi?iiiijijiii:jil I 1883 I ItK;;;;;.Iti'W:;;;;;~I 1182 I ~;:';iii;!.;iiE 11881 ~-------------------~-----------------t---f&iii__iiiiiiis,a I 1881 l-JiSmE,'w:liiiiilip,m::f.i·1 I 1812 I r,;;;::,I :fl~H;;;;;fjmiiM I 188 I I I I •1--I .--r--I I I I 7/7 7/21 8/4 elfa 8/1 8/10 I 8/28 ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 16 Woodward·Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE )1 ))1 J "J 1 ,j )J }I l 1 J 1983 ."lin. \, \, I I I \ \ I \ \ \ \ \...... I t .\ ~I Ie /'.I..."• I \J 11 11 AUG.- ~ ", I , I,: I I , I I I I I I 1,- I I • \"II, •II ! :z f, !:!1\ o ",~~\", ~ § 10 11.1 40 3+100 ~...... :E ~ Ii 1.I-f..eo % % II>... o -1... II!'T. 1981 ,, I \ \ \ \ \""-,,'---.., A,, I I 'I • "I \ I I I \." AUG. l I \/'I II I I I , I I I ,I : I I I II'I III / I ,"I'I I , I , I I I '.J N- ,"-, \ \I' V,I \, I \I """ ~ § ! '"... !:! o 10 8+130 4+110 "+'0 .+70 ~... w % ~ ~ II: % ~ % ~... o... o -rn § COMPARISON OF COHO SALMON FISHWHEEL CATCH AND MAINSTEM DISCHARGE AT SUNSHINE STATION (RM 80), 1981-1983. HARZA-EBASCO SUSITNA JOINT·VENTURE ALASKA POWER AUTHORITY SUSITNA HYDROElECTRIC PROJECT Woodward-Clyde Consultants and ENTRIX,INC.FIGURE 17 .....WtEEl CATCH (FC) OUICHAjiGE (OJI aI!'T. 1982 1\ , I I\.,\ I \", '""...-v ~,I,'\I II , I I , I ,'.I I I, I I I :I I I I I • , I I I I 'J I I , I I I!I I~../''0 ~!:!... -inc.lude escapements downstream of RM 22 (Barrett et ale 1985). Mos·t coho salmon in the Susitna River spawn in tributaries dowJnstream of RM 80·(Barrett et ale 1985). The annual coho salmon escapement for 1981 through 1984 ave:raged 5,700 fish at Talkeetna station (RM 103)(Table 6), with a range of 2,400 to 11,800 (Barrett et ale 1984,1985). Thel;e escapements overestimate the number of fish that spawn upstream of RM 103 because a significant number of fish return dowllstream below Talkeetna station (Barrett et ale 1984,1985). In 1984,approximately 75 percent of the coho escapement to Talkeetna Station returned downstream to spawn (Barrett et ale 198!»•If the 1984 escapement (11,800 fish)to Talkeetna stat.ion is reduced to account for the milling component of the run J,the Talkeetna-to-oevil Canyon reach accounted for less than 2 percent of the 1984 coho escapement to Flathorn Station (Barrett et ale 1985).The milling co~ponents of the coho esc2lpements to Talkeetna station were not estimated in 1981, 198;~,or 1983. (iii)Migration Rate Tag~red coho salmon traveled from Sunshine station (RM 80)to Talkeetna station (RM 103)at average rates of 4.0 miles per day (mpd)in 1981,5.3 mpd in 1982,1.4 mpd in 1983 and 2.9 mpd in 1984 (Barrett et ale 1984,1985).Coho salmon migrated bet~reen Talkeetna Station and Curry Station (RM 120)at an average rate of:11.3 mpd in 1981,10.0 mpd in 1982,5.7 mpd in 1983i and 2.8 mpd in 1984 (Barrett et ale 1984,1985). (iv)Spawning Locations Almclst all coho salmon in the Talkeetna-to-Oevil Canyon reach (RM 98.6-152)spawn in tributaries (Barrett et ale 1984,1985). OnlY'seven coho salmon have been observed spawning in mainstem and slough habitats.In 1981,one fish was captured in the 60 mainstem at RM 129.2,in 1983 two coho salmon were observed spawning in the mainstem at RM 131.1 and in 1984 two fish were observed in the mainstem at RM 131.5.Two fish were observed F'"spa'WIling in Slough 8A (RM 125 ~1)on October 2,1982 (ADF&G 1982a). COhlD salmon peak index counts in tributary streams upstream of RM 98.6 were:458 fish in 1981,633 fish in 1982,240 fish in 198:3 and 1,434 fish in 1984 (Barrett et a1.1984,1985). Twelve tributary streams upstream of RM 98.6 contained coho salmon during index surveys in 1981 through 1984.Peak index COUJlts greater than 10 fish in all four years were recorded in: Whi!:lkers Creek,Chase Creek,Gash Creek,Lower McKenzie Creek, Ind:lan River and Portage Creek (Table 16).The two most imp()rtant tributary streams for coho spawning were:Gash Creek and Indian River in 1981,Whiskers Creek and Lower McKenzie CreE~k in 1982,Whiskers Creek and Indian River in 1983 and Indian River and Whiskers Creek in 1984. Coh()spawning in tributary streams upstream of RM 98.6 usually occurred between the last week of August and the first week of Oct()ber in 1981, 1982,1983 and 1984 (ADF&G 1981a,1982a; Barrett et ale 1984,1985). (v)Access Pass;age conditions into tributaries for coho salmon are similar to the conditions described for chum salmon (see section 4.1.,2,v). -(vi)Fecundity and Sex Ratio - The mean fecundity of coho salmon in the Susitna River is 2,800 eggsl per female (Barrett et ale 1985).This estimated fectmdity is derived from the regression analysis of fecundity 61 .~Table 16.COho salmon peak index counts in streams upstream of RM 98.6, 1981-1984. SOlJIx:e:ADF&G 1981a,1982a;Earrettet al.1984,1985 1 FclUr-year average of totals 62 - - as a function of length and from the mean length of coho salmon femslles sampled at Sunshine station (Barrett et ale 1985). The sex ratio (male to female)of coho salmon in the Susitna RivE~r was 0.9:1 in 1981,1.4:1 in 1982,1.3:1 in 1983 and 1.2:1 in 1984 (ADF&G 1981a,1982a;Barrett et ale 1984,1985).The sex ratios varied between years and sites (Table 17).Sex ra''l:-ios of coho salmon by age are reported by ADF&G (ADF&G 1981a,1982a;Barrett et ale 198t..,1985).Most returning adult cohcl were three or four year old fish that'had gone to sea aftetr one or two years in freshwater (ADF&G 1981a,1982a; Barrett et ale 1984,1985). 4.1.4 Pink Salmon (i)Timing of Run Pink:salmon enter the Susitna River in late June to early July and are present in the lower river at Yentna station (RM 28, TRM 04)between the second week of July and the third week of August (Barrett et ale 1984,1985).In the Talkeetna-to-Devil Canyon sub-basin (RM 98.6-152),the pink salmon migration in the mainstem lasts about 4 weeks from the fourth week of July to the third week of August (Barrett et ale 1984,1985).A sWtllD,ary of pink migration timing in the Susitna River for 1981, 1982 and 1983 is presented in Figure 18. Upstream movements of pink salmon are likely influenced by peak discharge levels.River discharge levels of 100,000 cfs or greater at Sunshine Station coincided with reduced fishwheel catches at Sunshine station i1 1981 and 1983 and apparently delayed the migrations (Figure 19). 63 ·.... -Table 17.Sex ratios of coho salmon at flathom,SUsitna,yentna,SUnshine, Talkeetna and CIlrJ:y stations,1981-1984. IDca,tion,l Sex ratio CM:F)1 -RiVEIr Mile 1981 1982 1983 1984 Flathom Station 1.4:1 RM 22 SUsi.tna station 0.8:1 0.6:1 RM 26 Yentna station 0.9:1 2.4:1 2.3:1 0.8:1-RM 28,TRM 04 SUnshine station 0.7:1 1.4:1 1.2:1 1.2:1 RM 80 """ Talkeetna.station 1.5:1 1.5:1 1.7:1 1.1:1 RM 1.03-Cl1rl:y Station 2.0:1 1.3:1 2.0:1 1.1:1 RM 120 - • I ~., Source:ADF&G 1981a,1982ai Barrett et ale 1984,1985 1 Il'lcludes all aged.and non-aged.fish Dashes indicate no sw::vey 64 ~.J ]-],J -i ~l »-J -1 j J .oJ J 1 ]J ) I I PIN K SALMON I I M.dla.P.a II ti..··.,.::~:ca~e..t-6;;rtj;Z,?;W;i:ji'2i.;;:;;';l 1188~ CURRY -I ~&,-,;I~t"i I .;:;;W;I 1•••2 STAT 10 H 501.ClIlllula'lv.10%ell.ulatlv.I Calc"fl.'Effo,t Colell fl.'("0,1 I ~3;iyimfriiditii¥!.i;,:AT,1:i;;1 11881 ~------------~-----------------~------------ TALKEETNA. STATION I mi~tez·:t'.j::;:;;;;;;'::.1188 ~ I Eiij:;;M;::;F]1 1882 J--I·::r;;·:&&dt·J:'i;j.iiLt;;.,·:tii:::;·;:'H¥:1 .I 1881 0"1 U1 SUNSHINE •STATION YEHTNA.• STATION ....------..--...--------....------------------------ I Iii;:;;»;;;;;;;I't~;;:r<v>&:r;;vi II'"y"'"I"·".:iJ'"",>1883 I ~;>Ii:;;Gm;;1 11882 I I-;~:::'I~;!:•.'''Gif'!',;;I Irii·....:..,.::v..!..::..\1'hi :.:-i....).::/....;,:.,;".'..:-:I8 8 I ~---~----_..-------~~-----~~-----------------~ I 1·;;:gr.UY.;::ii,i·<I:i::,:;;;,i:@tt,tifT>::I"·;;;,;;:··:1 1188~ ,r.------fr:YbS ···f:;1iimr;.J,;;x:f 1 1882 I I,'li::J K:F:u';;ir:;:ii:;:i;iS:;;:t h ;:t;:.t:.i,Jii,i4';':k:.·.::\;it::H 1881 I • I • I I I I I •I I I I .--. 8/28 7/8 7/18 '/28 8/7 8/17 8/27 8/8 DATE MIGRATIONAL TIMING OF PINK SALMON BASED ON FISHWHEEL CATCH PER UNIT EFFORT AT SELECTED LOCATIONS ON THE SUSITNA RIVER IN 1981,1982 AND 1983.(SOURCE:BARRETT et at 1984)•• ALASKA POWER AUTHORiTY SUSITNA HYDROELECTRIC PROJECT FIGURE 18 Woodward.Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSiTNA JOINT·VENTURE »J 1 1 .~}j 1 ]1 »l J 1 )1 ] oAIlV '0 ASHWHEEl CArCM (FCI DISCHARGE (01 COMPARISON OF PINK SALMON FISHWHEEL CATCH AND MAINSTEM DISCHARGE AT SUNSHINE STATION (RM 80),1981-1983. 40 4 8 , ~ .AllY 180+100 1982 ~ I' 140--1 "1 eo I 1 110-1 , II JI 1 -\1,'....'VI\J 1 .....0 \..ill , I x 0 ,; /\ '\ ~0 I ,, I 0 \ ,r' ~, I \.I \'-'\.1 \ a: ! I \I :r ,, \ i 0> '-"''''-''J \, .. '-.r 0> 40 ~IL 0 <> IL <> IL II: X, X '" .......x ~ I "r'"I Too '~I II,,••,I !\'••3 , , I',I e-i , \eo,~ uo ,I 3 I , I 'r,l'I II"I\!,,'.:\,I ~~ I ,I '-'\'\, \I '...\'\_I r--,/':::80 _\ ~,'._.\\:r ~\\/\g I '"\ ,~g ,-_,'"\ o I \1 ,/\'0 \\'"80 ~I I \IX ~\/',;, , '!I \1 V,~!\t ...,'.' \ en J \x II>Ju\I I ~'0 u-,""'-..,......~- 0\I "-0 \ ,'.<>, I ILV1\\\~~\,......'"--- 0'1 0'1 ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT10 10 MY AUG.UPT.FIGURE 19 Woodward-Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT·VENTURE ~I (ii)Escapement Pin}\{salmon have a two-year life cycle that results in two genletically distinct stocks occurring in each stream.In the susitna Basin,the even-year runs are numerically dominant (Barrett et al.1984,1985).The odd-year pink salmon minimum escapement in the Susitna River averaged 93,400 fish for 1981 and 1983,while the even-year minimum escapement averaged 1,1:38,400 fish for 1982 and 1984 (Table 6).These estimates are based on the summation of escapements at Yentna and Sunfshine Stations and do not include escapements downstream of RM 80,excluding the Yentna River (RM 28).In 1984,'about 3,6:29,900 pink salmon reached Flathorn Station(RM 22)(Barrett et al.1985).This estimate is based on data from the first yea]~of monitoring at this location and does not include escapements downstream of RM 22 (Barrett et al.1985).Most pinJc salmon in the Susitna River spawn downstream from the Chulitna River confluence (RM 98.6)(Barrett et al.1984, 1985). The 1981 and 1983 odd-year pink salmon escapements averaged 5,900 fish annually at Talkeetna Station (RM 103)(Table 6), with a range of 2,300 to 9,500 fish (Barrett et al.1984, 1985).The even-year escapement at Talkeetna station was 177,900 fish in 1982 and 73,000 fish in 1984 (Barrett et al. 1984"1985).The escapements at Talkeetna station overestimate the number of fish that spawn upstream of RM 103 because a sigrlificant number of fish return downstream below Talkeetna St~a1::ion (Barrett et al.1984,1985).In 1984,about 85 percent of t:he pink escapement to Talkeetna station returned downstream to spawn (Barrett et al.1985).If the 1984 escapement (177,900 fish)to Talkeetna Station is reduced to account for the milling factor,the Talkeetna-to-Devil Canyon reach accclunted for less than 1 percent of the 1984 pink escapement to Flathorn Station (Barrett et al.1985).The milling 67 components of the pink escapements to Talkeetna station were not estimated in 1981,1982,or 1983. (iii)Migration Rate ,~ - - Taglged pink salmon migrated from Sunshine station (RM 80)to Talkeetna Station (RM 103)at average rates of speed of 2.6 .milles per day (mpd)in 1981,7.4 mpd in 1982,5.9 mpd in 1983 and 5.9 mpd in 1984 (Barrett et al.1984,1985).The average rates of travel increased between Talkeetna station and Curry sta'l:ion (RM 120):6.0 mpd in 1981,10.0 mpd in 1982,7.1 mpd in 198:3 and 9.4 mpd in 1984 (Barrett et al.1984,1985). (iv)Spawning Locations The majority of pink salmon in the Ta1keetna-to-Devi1 canyon rea<::h (RM 98.6-152)spawn in tributaries (Barrett et al.1984, 198!5)•Peak index counts for streams upstream of RM 98.6 were 378 fish in 1981,2,855 fish in 1982,1,329 fis'h in 1983 and and 17,505 fish in 1984 (Table 18).In 1981,Lane Creek,Chase Cretak and Fourth of July Creek accounted for almost 95 percent of 'I:he total peak counts of 378 fish.In 1982,when the pink sallnon escapement in the Susitna River was at an even-year high,eight streams accounted for almost 93 percent of the total count of 2,855 fish (Table 18).Indian River,Portage CreEak and Fourth of July Creek were the most important pink salmon spawning streams in 1983;the three streams collectively had a peak index count of 1,249 fish,or about 94 percent of the total peak count of 1,329 fish.In 1984,85 percent of the total peak count in streams was observed in Indian River, Po_1:age Creek,Fourth of July Creek,and Lower McKenzie Creek (Barrett et al.1985).Spawning activity in streams occurred prilllarily during the first three weeks of August in all four years (ADF&G 1981a,1982a;Barrett et al.1984,1985). 68 Tablla 18.Pink salmon peak Wex counts in streams upstream of RM 98.6, 1981-1984. River o:id-Year Even-Year-stream Mile 1981 1982 1983 1984 Average Average Whiskers creek 101.4 1 138 0 293 1 216 ~~ Cl:1asa creek 106.9 10738 6 438 22 273 Slash creek 111.2 0 0 0 3 0 2 Gash Creek 111.6 0 0 0 6 0 3 lane Creek 113.6 291 640 28 1,184 160 912 ClydEa Creek 113.8 0 0 0 34 0 17 Maggc)t Creek 115.6 0 0 0 107 0 54 IDiNeJ::'McKenzie Cr.116.2 0 23 17 585 9 304 McKeIlZie Creek 116.7 0 17 0 11 0 14 Little Portage Cr.117.7.0 140 7 162 4 151 Fram.Jn2 Creek 119.3 /0 0 0 40 0 20 I:Ow:nun:ia Creek 119.4 0 0 0 6 0 3 Dead1'lorse creek 120.8 0 0 0 337 0 169 Tulip Creek 120.9 0 0 0 8 0 4 Fiftl.lof July Cr.123.7 2 113 9 411 6 262 Skull Creek 124.7 8 12 1 121 5 67 ~..:nt1an Creek 130.8 6 24 0 48 I 3 36 ~Fourth of July Cr.131.1 29 702 78 1,842 54 1,272 Gold Creek 136.7 0 11 7 82 4 47 IOOiclIl River 138.6 2 738 886 9,066 444 4,902 Jack I.onq Creek 144.5 1 21 5 14 3 18 Portage Creek 148.9 0 169 285 2,707 143 1,438 Total 378 2,855 1,329 17,505 8541 10,1802 Source:Barrett et ale 1984,1985 1 Odd.-year average of totals 2 E.."ven-year average of totals 69 - "... - """ PinJ<~salmon were observed spawning in slough habitat in 1981, 1982:and 1984.Total slough escapement upstream of RM 98.6 in 1981.was 38 fish in Slough 8 (Table 19).In 1982,total slough esca.pement upstream of RM 98.6 was 297 fish in seven sloughs (Table 19).Two of the seven sloughs (11 and 20)accounted for ove~'80 percent of the escapement.No pink salmon were obse,rved spawning in sloughs in 1983;fish counted in slough habitat during spawning surveys were considered milling fish (Bar'rett et ale 1984).In 1984,the total pink salmon escapement upstream of RM 98.6 was 647 fish (Table 19).The three most important sloughs were:8A,11 and 20.In 1981 the peak.of spawning activity in sloughs occurred about the last week of August,in 1982 it occurred during the first three week.s of August and in 1984 it ranged from the second week of August to the first week of September (ADF&G 1981a,1982a; Barrett et ale 1985). (v)Access Passage conditions of salmon into sloughs and tributaries in the Talkeetna-to-Devil Canyon reach have been discussed previously (see sections 4.1.1,v and 4.1.2,V). Sloughs 8A,11 and 20 appear to be important pink salmon spawning areas (Table 19).Breaching and backwater effects at Sloughs 8A and 11 have been discussed previously (see section 4.1.1,v)•The upstream passage of salmon into Slough 20 is apparently provided for by the local flow from Waterfall Creek (Sautner et ale 1984).Most pink salmon spawning occurs below Waterfall Creek (Sautner et ale 1984,1985). (vi)Fecundity and Sex Ratio The predicted fecundity for Susitna River pink salmon is about 1,350 eggs per female,which is based on the regression 70 Table 19.pink salmon total slough escapement upstream of RM 98.6,1981-1984. -River Odd-Year Even-Year Slough Mile 1981 1982 1983 1984 Average Average- 3B 101.4 0 0 0 34 0 17 3A 101.9 0 0 0 67 0 34 5 107.6 0 0 0 5 0 3 8 113.7 38 0 0 0 19 0 Bush:rod 117.8 0 0 0 12 0 6 I"""8B 122.2 0 0 0 82 0 41 Moose 123.5 0 2 0 0 0 1 A'124.6 0 0 0 29 0 15 8A 125.1 0 5 0 161 0 83,.... B 126.3 0 18 0 0 0 9 9 128.3 0 18 0 0 0 9 11 135.3 0 170 0 145 0 158 .-20 140.0 0 75 0 102 0 89r 21 141.1 0 9 0 10 0 10 Total 38 297 o 647 Sourt::e:Barrett et ale 1984,1985 1 o:ici-year average of totals 2 EvE:m-year average of totals 71 ..... , analysis of fecundity as a function of length and the me,an length of all female pink salmon measured at Sunshine station in 1983 (Barrett et al.1984)• The sex ratio (male to female)of all pink salmon sampled in the Susitna River was:0.8:1 in 1981,1.4:1 in 1982,0.9:1 in 1983 and 1.3:1 in 1984 (ADF&G 1981a,1982a;Barrett et al. 1984,1985).Sex ratios at sampling locations in the Susitna River for 1981 through 1984 are presented in Table 20.All pillk salmon returning to the Susitna River are two year old fish that went to sea in their first summer of life (ADF&G 1981a,1982a;Barrett et a1.1984,1985). 4.1.5 Chinook Salmon (i)Timing of Run ~ I ,.,... - ~. Chinc)ok salmon enter the Susitna River in late May to early June"In the lower river,most chinook (over 90 ,percent)have migrated past susitna station (RM 26)by JUly 1 (ADF&G 1972). The chinook salmon migration at Sunshine station (RM 80)lasts for i:lbout one month between early June and early July (Barrett et al.1984,1985).In the Talkeetna-to-Devil Canyon reach (RM 98.6··152),the chinook migration in the mainstem lasts for abou1~one month from mid-June to mid-July.A summary of chi.nc)ok migration timing in the Susitna River for 1981,1982 and 1983 is presented in Figure 20. Chinc)ok migration timing may be influenced by river discharge (ADF&IG 1982a).During 1981 and 1982 river discharge peaks cni.nc:ided with reduced fishwheel catches at Sunshine station 72 Table 20.Sex ratios of pink salmon at Flathom,SUsitna,Yentna,sunshine, Talkeetna and CUrry stations,1981-1984. I""" I.oca:tion;Sex ratio m:F) Rivet'Mile 1981 1982 1983 1984 ~Flathom station 1.3:1 RM 2:2 SUsitna.station 0.4:1 0.9:1 RM 215 YentJ:'la station 0.8:1 1.0:1 0.9:1 1.2:1 RM 213,'mM 04 Sunshine station 0.8:1 1.8:1 1.0:1 1.1:1 1"""RM 80 Ta1Ja~tna station 1.2:1 1.6:1 0.8:1 1.1:1 RM 103 ~{station 0.8:1 1.5:1 1.0:1 1.6:1 RM 1.:20 SOlJrc::e:Barrett at ale 1984,1985 DashE:!S iniicate no survey :f'.JIUP 73 J 1 )J )l J J J 1 ))j 1 CURRY STATION" I I "•rCHINOOK SALMON I I I 'u ;:;;H;,".::::::::::::;;,,::1 I 1983 I ."111"M~lall ~::C'II J t.'i.TI."qj!t ·I····:i/;t.·~··H...I f r----rI ::r.:c .''~'1---f::;};::;:'::;U;}:;:E:::*r:...:::\"1982 5,.:C-ulatlYl 9~%CU"'U~t1y. QUe Ii plr Effor'Calch p.r Effor' ~.::..'.·:.:·:LHi?'!.....;:':1:''i:::,:u '\;::1 119~""-1 -------- ~-...-..----_...._----------------..........-....--------- TALKEETNA STATION ... 11 __~I::,?±·:p.ly!··,~i'!>t;:?·?lT'!'·;;:.·.:ns\Wi'e..;1 '198"."'~.t:'!;..~..r;:·G·su,"~:::~~:·:;·:t;;·_~ I m5':t.!}¥l·t:::,;::Ftd'fJiZ.::i l 11982 I I:d!;:::;'d::::f';!';!:~1 1982 -..J ~I .d.·.·.·,·p.w!i..·\l~.'??:::@,.·II 11981q:-::.t);:;"'i;;::::::s:~. J.----------------------------------------..--- --- SUNSHINE •H::;:!::1 I::::i:;::;:::u .:'::1 11983 STATION - 6/~ --.,, 6/19 , I , , , •I I • 7/3 7/17 7/31 8/14 8/28 DATE MIGRATIONAL TIMING OF CHINOOK SALMON BASED ON FISHWHEEl CATCH PER UNIT EFFORT AT SELECTED lOCATIONS ON THE SUSITNA RIVER IN 1981,1982 AND 1983.(SOURCE:BARRETT et a!.1984) ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 20 Woodward-Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT-VENTURE - ""'", - (Fig~re 21).However,in 1983 reduced fishwheel catches during the chinook migration did not coincide with the peak river discharges.The relationship of river discharge (above 100,000 cfs)with reduced fishwheel catches at Sunshine station is not as clear for chinook ~almon as it is for sockeye,chum,coho and pink salmon. (ii)Escapement The minimum chinook salmon escapement in the Susitna River in 1983 was approximately 125,000 fish.This estimate is based on 1983 chinook stream surveys (Table 21)(Barrett et al.1984) and the relationship that a peak chinook survey count represents at most 52 percent of the total escapement (Neilsen and Geen 1981).The total escapement derived by this method should be viewed as an approximation because:(1)the 1983 surveys did not include all known chinook spawning streams in the Susitna Basin (Barrett et al.1984);(2)counts may not represent peak numbers as some streams were surveyed only once; and (3)the relationship that a peak survey count represents at most 52 percent of the total escapement may not apply to Susitna River chinook.In 1984,the chinook salmon total escapement in the Susitna River was about 250,000 fish (Barrett et al.1985).This estimate is based on the estimated .escapement to Sunshine station (RM 80)of 121,700 fish and stream surveys (Barrett et al.1985). The annual chinook salmon escapements at Talkeetna station (RM 103)for 1982 through 1984 averaged 16,700 fish (Table 6),with a range of 10,900 to 24,800 (Barrett et al.1984,1985).These esca:pements overestimati..the number of fish that spawn upstream of RM 103 because a significant part of the escapement returns down:stream below Talkeetna Station (Barrett et al.1984,1985). In 1984, Talkeetna about 45 station percent (RM 103) of the chinook escapement to returned downstream to spawn 75 1 ···-1 l 1 }1 ")1 .-1 1 J •1 J 7 (\ ,~_~,"\"I "v V \ \ \ \ L_I, \I \.I',\'v"'",I.....' A,1,,,, J\,,, .... \ \ \ o iii iiio 8 .... ~o 4+10 ... III III %• u.. a: % % !?.. .... iii....u •_. o \\ I,,,,,,,,,.,,,,..,,/......, 40 I II AM tlO iii 10 go a.' I.' -' III III J:• a: % u.. J:.... I 't·..I.,I T'~1993 I II!\1981 I I'\,\-,\ I I, I I ,,\,\ I r---. I \'\ I ...",\ 1 \~ 1 I, I I -..Jcr. I' :; III III :I: "a:4 % %.... u.. I tOO 10 ,'"~ I'I \:'f.,,,, 10 :",~\I ,I~1\'\1'/ 8'V \ "~," iii 'v'.. 40 ~ o J. 1982 ",,, I , , I,,,','.J, ".',"/\, /.."r I .....WHEEL CATCH (Fe) D'SCHAltOE (0) COMPARISON OF ~HINOOK SALMON FISHWHEEL CATCH AND -MAINSTEM DISCHARGE AT SUNSHINE STATION (RM 80), 1981-1983. ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT ·10 .AlNE No-"FIGURE 21 Woodward·Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT·VENTURE lJ 1 --1 .OJ l I 1 OJ -J 1 j }1 1 Table 21.Chinook salmon peak survey escapement counts of susitna River streams by sub-basin from 1976 to 1984. Sub-basin 1976 1977 1978 1979 1980 1981 1982 1983 1984 Lower SUSitna sub-basin1 Alexarrler Creek 5,412 9,246 5,854 6,215 a a 2,546e 3,755 4,620 Deshka River 21,693 39,642 24,639 27,385 a a 16,000d 19,237 16,892 Goose Creek 160 133 283 b a 262 140d 477 258 Kashwitna River (North Fork)203 336 362 457 a 557 156d 297 111C Little Willow Creek 833 598 436 324 c a 459 316d 1,042 b Montana Creek 1,445 1,443 881 1,094C a 814 887d 1,641 2,309 Sheep Creek 455 630 1,209 778 a 1,013 527 945 1,028 SUcker Creek (Alexar.der Creek)b b b b b b b 597 b Willow Creek 1,660 1,065 1,661 1,086 a 1,357 592d 777 2,789 Wolverine Creek (Alexar.der Creek)b b b b b b b 491 b -...J SUbtotal 31,861 53,093 35,325 37,339 -4,462 21,164 29,259 28,007-...J Yentna sub-basin2 camp Creek (lake Creek)b b b b b b b 1,050 b canyon Creek 44 135 b b b 84 b 575 b lake Creek 3,735 7,391 8,931 4,196 a a 3,577 7,075 a Peters Creek 2,280 4,102 1,335 a a a a 2,272 a Quartz Creek b 8 b b b 8 b b b Red Creek b 1,511 385 b b 749 b b b sunflower Creek (lake Creek)b b b b b b b 2,250 b Talachulitna River 1,319 1,856 1,375 1,648 a 2,129 3,101 10,014 6,138C SUbtotal 7,378 15,003 12,026 5,844 --2,970 6,678 23,236 6,138 Talkeetna-c1lulitna sub-basin3 Bunco Creek 112 136 a 58 a a 198d 523 51d Byers Creek 53 69 a 28 a a 7 b 39 Chulitna River 124 229 62 a a a 100d b b Chulitna River ,East Fork)112 168 59 a a a 119d b b )~l 1 1 ._)'}1 J 1 ~]]1 ]]1 Table 2l.(continued) SUb-basin 1976 1977 1978 1979 1980 1981 1982 1983 1984 Chulitna River (Middle Fork)1,870 1,782 900 a a a 644d 3,846 4,191cClearCreek(Chunilna)1,237 769 997 864C a a 982d 806 1,520 Honolulu Creek 24 36 13 37 a a 27 b b Prairie Creek 6,513 5,790 5,154 a a 1,900 3,844d 3,200e 9,000 Troublescnne Creek 92 95 a a a a 36 b b SUbtotal 10,137 9,074 7,185 987 -1,900 5,957 8,375 14,801 Talkeetna-Devil canyon sub-basin4 Chase creek 5 b b b b b b 15 15 3 Cheechako ~b b b b b b 16 25 29 -..J Chinook~b b b b b b 5 8 15(Xl Devil Creek b b b b b b b 1 0 Fifth of '5uly Creek b b b b b b b b 17 Fog Creek b b b b b b b b 2 Fourth of July Creek b b b b b b 56 6 92 Gold Creek b b b b b b 21 23 23 Irrlian River 537 393 114 285 a 422 1,053 1,193 1,456 Jack Lorq Creek b b b b b b 2 6 7 lane creek b b b b b 40 47 12 23 Portage creek 702 374 140 190 a 659 1,253 3,140 5,446 Whiskers creek b b b b b b b 3 67 - SUbtotal 1,239 767 254 475 -1,121 2,474 4,432 7,180 IDrAL 50,615 77,937 54,790 44,645 10,453 36,273 65,302 56,126 ~No total count due to high turbid water Not COl..ll1ted c Poor COl..ll1ting conditions d Col..ll1ts conducted after peak spawning e Estimated peak spawning COl..ll1t ~RM 0-80,excluding the Yentna sub-basin 3 RM 28,Yentna River drainage 4 RM 80-98.6 5 RM 98.6-152 AOOve RM 152 (Barrett et al.1985).If the 1984 escapement (24,800)to Talkeetna station is reduced to account for the milling factor, the Talkeetna-to-Devil Canyon reach accounted for about 5 percent of the 1984 Susitna River chinook escapement (Barrett et al.1985)•The milling components ,:;,f the chinook escapements to Talkeetna station were not estimated in 1982 and 1983.Chinook salmon escapements at Talkeetna station (and at the other sampling locations in the Susitna River)were not I'*' estimated in 1981. Tagged chinook salmon migrated between Sunshine station (RM 80) and Talkeetna station (RM103)at an average rate of travel of 2.1 miles per day (mpd)in 1982,1.8 mpd in 1983 and 3.3 mpd in 1984 (Barrett et al.1984,1985).The average rate of travel bet'ween Talkeetna Station and Curry ,Station (RM 120)was 2.2 mpd in 1982,2.7 mpd in 1983 and 4.3 mpd in 1984 (Barrett et al.1984,1985). - (iii)Migration Rate - (iv)Spawning Locations III the Talkeetna-to-Oevil Canyon reach (RM 98.5-152)chinook salmon spawn exclusively in tributaries (Barrett et al.1984, 198:5)•Peak index counts in streams upstream of RM 98.6 were: 1,121 fish in 1981,2,474 fish in 1982,4,432 fish in 1983 and 7,180 fish in 1984 (Table 22). The total chinook salmon escapement to streams upstream of RM 98.6 was estimated by the relationship that a maximum survey count represents at most 52 percent of the total escapement (Nilalson and Geen 1981).Based on this method,the total eSCi3.pement to streams upstream of RM 98.6 was about 2,150 fish in :1981,4,750 fish in 1982,8,500 fish in 1983 and 13,800 fish in 1984.These escapements should be viewed as approximations beci3.use:(1)in 1981 not all chinook salmon spawning streams 79 Table 22.Chinook salmon peak index counts in streams upstream of RM 98.6, 1981-1984. River Four-Year stream Mile 1981 1982 1983 1984 Average Whiskers creek 101.4 0 3 67 ChaSle creek 106.9 15 15 3 lane creek 113.6 40 47 12 23 31 Fiftb.of July creek 123.7 3 0 17 Shel:1:Dan Creek 130.8 3 0 0 Fourth of July creek 131.0 56 6 92 Gold creek 136.7 21 23 23 !""""Indilm River 138.6 422 1,053 1,193 1,456 1,031 Jack Long creek 144.5 2 6 7 Portage Creek 148.9 659 1,253 3,140 5,446 2,625 f....Cheechako creek 152.5 16 25 29 Chin(:dc Creek 156.8 5 8 15 Devil Creek 161.0 0 1 I 0 ,~ Fog Creek 176.7 0 0 2 ........Total 1,121 2,474 4,432 7,180 3,8021 .-SOlm:::e:ADF&G 1981a,1982a;Bal:rett et ale 1984,1985 1 Four-year average of totals DashE~indicate no survey in 1981;no four-year average 80 -were surveyed upstream of RM 98.6;and (2)more importantly, the relationship that a peak count represents at most 52 percent of the total escapement may not be valid for Susitna River chinook salmon. Portage Creek and Indian River are the two most important tributary streams for chinook salmon spawning in the Susitna River upstream of RM 98.6 (Barrett et ale 1984).The two-streams accounted for over 90 percent of the pe~k index counts in 1981 through 1984 (Table 22). The peak of the spawning activity in tributaries upstream of -RM 98.6 was between the last week of July and the first week of '.August in 1981,1982 and 1983 (ADF&G 1981a,1982a,Barrett et ale 1984). (v)Access - - - - Salmlon are usually prevented from migrating upstream of Devil Canyon (RM 152)because of the high water velocity.Low flows in 1982,1983 and 1984 allowed a few chinook salmon to pass through Devil Canyon.In 1982,21 chinook salmon were observed in two tributaries in upper Devil Canyon (ADF&G 1982a).In 1983,34 chinook salmon were observed in three tributaries in Uppell:'Devil Canyon (Table 22).In 1984,46 fish were observed in three tributaries in upper Devil Canyon (Table 22). TrihE~y (1983)examined the hydraulic conditions supporting fish passage into Indian River and Portage Creek,which are the two most important streams for chinook spawning in the Talkeetna- to-DE~vil Canyon sub-basin.Trihey's analysis indicated that passclge of salmon into these two tributaries is not likely to be impeded at low mainstem discharge. 81 -I I (vi)Fecundity and Sex Ratio The fecundity of chinook salmon has not been estimated in the Susitna River,but is expected to be in the range of 4,200 to 13,600 eggs per female,as reported by Morrow (1980). The sex ratio (male to female)of chinook salmon in the Susitna River was 2.8:1 in 1981,1.4:1 in 1982,1.5:1 in 1983 and 1.1:1 in JL984 (ADF&G 1981a,1982a;Barrett et a1.1984,1985).Sex rati.os at sampling locations in the Susitna River for 1981 thro1ugh 1984 are presented in Table 23.Sex ratios by age are... repolrted by ADF&G (ADF&G 1981a,1982a;Barrett et ale 1984, 1985).Most returning adult chinook salmon were five,six,or seven year old fish that had gone to sea after one year in freshwater (ADF&G 1981a,1982a;Barrett et ale 1984,1985). 4.2 INCUBATION Salmon egg incubation in the middle reach (RM 98.,6-152)of the susitna River begins in July with chinook spawning in tributaries and tributary mouths.This is followed by pink salm.on in mid-to late August and chum and sockeye in late August to early September.Chum incubation begins about one week earlier in the tributaries than in the sloughs. Incubation of sockeye in sloughs begins at about the same time as chum incubation.The last species to spawn are coho salmon, which spawn almost exclusively in tributaries in September (ADF&G 1981a,1982a;Barrett et ale 1984,1985). Succ,assful incubation and emergence is dependent on numerous bioll:;)gical,chemical,and physical factc.::cs.These factors include dissolved oxygen,water temperature,surface water discharge,and intragravel permeability (Reiser and Bjornn 82 .-. Table 23.Sex ratios of chinook salmon at Yentna.,StJnsh.ine,Talkeetna.and CUrJ:y'stations I 1981-1984. """ Location;Sex ratio CM:Fl 1 River Mile 1981 1982 1983 1984 ~ Yen'b:la station 6.4:1 2.3:1 1.1:1 RM 213,TRM 04 Sunshine Station 3.5:1 1.2:1 1.2:1 1.0:1 ~RM 80 Tal]Q~station 2.7:1 2.3:1 2.4:1 1.1:1 RM 103 CUrry station 1.9:1 1.5:1 1.4:1 1.2:1 RM 1:20 SOUl:'t::e:Barrett et ale 1984,1985 1 Inc:ludes all aged ani non-aged fish Dashes in:iicate no survej ..... 83 ~- 1979).Droughts,floods,freezing imposition of redds,and predators can inc'ubation (McNeil 1969).The following factors.The information is derived Susitna River and other locations. 4.2.1 Dissolved Oxygen temperatures,super- also affect successful sections discuss these from studies on the Dissolved oxygen is needed during incubation to metabolic reactions.A literature review by Reiser (1979),concluded that: facilitate and Bjornn Sac fry incubated in low and intermediate oxygen concentrations were smaller and weaker than sac fry reared at higher concentrations; early stages increase (1) !- (2) - Low oxygen concentrations in the development may delay hatching, incidence of anomalies,or both;and of the - - - (3)Low oxygen concentrations during the latter stages of development may stimulate premature hatching. Brannon (1965)found apparent differences in characteristics of alevins that had been incubated at oxygen concentrations ranging from 3.0 to 11.9 mq/l.Slowed development was evident at low concentrations,but these fish eventually attained a weight similar to those raised in higher concentrations by the time they reached the fry stage. The intragravel flow of water is important in assuring that disslo1ved oxygen is made available to the inCUbating eggs and that metabolic wastes are removed.Reiser and Bjornn (1979) recommend that the apparent velocity through the gravel should 84 ..... .- be more than 20 em/hour,while Bell (1980)recommends a rate of 110 em/hour.Specific studies on intragravel flow have not been performed in the Susitna River. In f;tudies on four slo''lghs (8A,9,11,and 21)in the middle rivElr in April and May of 1983,ADF&G (1983a)found that mean conc:entrations of intragravel dissolved oxygen were cons~istently lower than mean concentrations for overlying sU.r£:ace waters.Means for intragravel concentrations ranged fronL 4.6 to 8.5 mg/l,whereas the surface waters ranged from 9.1 to 11.2 mg/l.The lowest intragravel concentrations occurred in Slough 8A and the highest in slough 11.Assuming that low dissolved oxygen levels occurred throughout the incubation period (rather than only the April and May sampling period),the low concentrations in Slough SA may have caused some delay in chum and sockeye development.Diversion of cold mainstem water through this slough as a result of an ice jam may also have contributed to delayed development.Development at t.he other three sloughs (9,11 and 21)foIl'embryos and alevins was generally uniform. McNeil and Bailey (1975)recommend a dissolved oxygen threshold of cLt least 6.0 mg/l for incubation,while Reiser and Bjornn (1979)recommend concentrations at or near saturation with temporary reductions to 5.0 mg/l.In general,for the Susitna River sloughs studied thus far,these recommendations are usually met.The excsption is the lower values found in Slough 8A and some concentrations in slough 9 (ADF&G 1983a). Biochemical oxygen demand (BOD),resulting from excessive amounts of organic material in the stream,can reduce dissolved oxygen levels (Reiser and Bjornn 1979).BOD levels have not been measured in the Susitna River.Under existing conditions, dissolved oxygen levels remain at or greater than saturation in the mainstem.Therefore,it is suspected that BOD is at low levels.Habitats adjacent to the mainstem may have higher BOO 85 levels due to the high organic content of waters (e.g.,upland sloughs),concentrations of dead post-spawned salmon (e.g.,in sidle sloughs)or movement of water through the groundwater system. 4,,2 ..2 Temperature Temperature and salmon embryo development are strongly intE~rrelated,with higher temperatures result.ing in more rapid development.Development is also related to species,time of egg deposition,and the temperature regime over the period of incubation.In general,the lower and upper limits for succ:essful initial incubation of salmon embryos are 4.5 and 14.:.OC (AEIDC 1984).Incubation can occur at lower temperatures if the initial temperature is greater than appI~oximately 4.oOc.This initial sensitivity to low temperatures is apparently related to embryo developmental phas:es because once the blastopore is closed on the developing embzyo,the sensitivity is reduced (Combs and Burrows 1957). For most species in the Susitna River,the timing of egg depolsition is sUfficiently early in the season to avoid low initial temperatures.The relationship between temperature and embryo development is frequently measured in temperature units (TUs).These are defined as the difference between the average temperature and cOc over 24 hours.For example,if eggs were incubated at 7 0 C for 5 days,the accumulated TO'S would be 35. If an embryo has accumulated 140 temperature units (the approximate ,developmental stage needed to achieve closing of the blastopore),then it probably has passed the temperature- sensitive stage fCombs and Burrows 195 F i).The peak spawning activity for most salmon in the Talkeetna-to-Devil Canyon reach (RM 98.6-152)occurs prior to September 1.This is the case for chinook and pink salmon (Barrett et al.1984).Chum and sockleye salmon overlap this period.However,they utilize areas of groundwater upwelling in the mainstem and sloughs that 86 - havEa temperatures throughout the winter that vary between 2 to 4°C"Coho salmon spawn late in the season.If they do not spa~m in upwelling areas (this is not known at the present timE~),embryos theoretically do not accumulate sufficient temperature units during this sensitive stage for proper development.Additional studies would be needed to fully undE~rstand if this species has different initial temperature requirements for successful incubation. studies by Wangaard and Burger (1983)have sho~that the time tOI emergence (complete yolk absorption)can vary considerably at different temperatures.In laboratory tests at average temperatures between 2.1 and 4.0 °c,these authors found that lower temperature would extend the time to complete yolk absorption for Susitna River chum and sockeye eggs from 30 to 60 days.There are some weak compensatory mechanisms that tend to counteract but not eliminate these differences.For example,Dong (1981)suggested that the accumulation of one temperature unit at low temperatures results dn a greater amount of development than the accumulation of one temperature unit at high temperature.However,this does not necessarily provide enough compensation so that eggs incubated under different regimes hatch at the same time.This was evident from the 30 to 60 day difference in complete yolk absorption shown in the studies of Wangaard and Burger (1983).Embryos incubated in colder water hatched at shorter lengths and required fewer TO's for hatching.However,mean alevin length at c:omplete yolk absorption did not reveal the corresponding difflerences.In summary,alevins at yolk absorption may be of similar size between two temperature ranges (in the 0 to 4 0 C ral'1ge),but alevins in the colder regi.::e would take longer to reacltl that stage while requiring fewer temperature units. The temperature/time of emergence relationship has been stUdied on the Skagit River in Washington (Graybill et al.1979).This rivelt:'has been affected by hydropower development for at least 87 - ..... 60 years.Present year-round water temperatures are generally warmer by several degrees than pre-proj ect temperatures (no actual pre-project temperatures have been recorded,however modE!ling has established a likely pre-project scenario).For chinook salmon,the timing for spawning has not been notic.i'ably altE!red,at least through records that date back to 1948. HOWE!Ver,it appears that emergence timing of Skagit River chinook has advanced by about one month.Pink salmon emergence has advanced by about 4 to 11 weeks and chum salmon by 0 to 5 weel<:s.The implications of this advancement in the Skagit River are not clear. Nume.rous authors have speculated that an advancement of emergence in any river system would not be specifically patt~erned to natural peak abundances in food organisms and therefore would not be advantageous to survival.Wangaard and Burg'er's (1983)finding of a 30 to 60 day delay in chum salmon em.ergence could mean that embryos incubated at the lower temperatures would result in fish that are out pf phase with the normal parr-smolt transformation (this transformation is the salmonid life phase when they undergo a physiological change so that they can adapt to a saltwater environment)and therefore,fish would not be viable.However,Wangaard and Burger state that the effect of early emergence on sockeye salmon was unclear because sockeye rear for one to two years in freshwater before they outmigrate. To slimplify the predictions for chum salmon incubation from fertilization to emergence,AEIDC (1984)has developed a nomol;Jraph with the variables of date of fertilization,average inculbation temr'erature,and date of emergence (Figure 22).If the date of spawning were known and an average incubation temp1erature assumed,the date at which emergence would occur could be predicted.This nomograph is useful for examining and estilnating potential changes in chum salmon incUbation periods unde:1:'a wide range of temperature regimes in the Susitna River. 88 Spawning Dote July 20 - AU91 - AuC;IO - Au,;20 - Sept I - Sept 10 - F Sept20 - I Oct I - OetlO -~ I ....1..- I !"'" T(C) I-1.0 ~L5 I-2.0 I- -2.5- •3.0 -3.5 l- I-4.0 I- ~4.5 l- I-5.0 I- ~5.5 I-6.0 I-6.5 .1-7.0 Emergence Dote ....1' ~June 10 •June I I-May20 I-May 10 I-May I I""April20 ~April 10 ~April I I-Morch 20 ~March 10 I March I I-Fee 20 -FeelO -Febl Jan 20 •Jan 10 I-Jon I CHUM SALMON SPAWNING TIME VERSUS MEAN INCUBATiON TEMPERATURE NOMAGRAPH (SOURCE:AEtDC 1984) ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FlGURE 22 Woodward-Clyde Consultants and ENTRIX,INC. 89 HARZA-EBASCO SUSITNA JOINT VENTURE r ,.... i ! 4.2.3 Substrate Salmon require certain substrate characteristics for successful spawning and incubation.The substrate must be capable of allowing sufficient flow to deliver dissolved oxygen to the embryos and carry away metabolic wastes.It also must not contain a high percentage of fine sediments which could cut off the flow or prevent emergence of fry.As a general guideline, Reiser and Bjornn (1979)recommend that the substrate used for incubation should contain less than 25 percent by volume of finles <6.4 nun. Subl3trate also cannot be excessively large because adult salmon generally are unable to excavate'large rocks or solid S'llbI3trate.Instead,they require intermediate-sized gravels. The substrate size used depends to some extent on the size and species of fish and the substrate that is available to the fish.Based on extensive field studies on the Susitna River by Vinc::ent-Lang et a1.(1984),chum salmon in sloughs can utilize substrates between 1 in.and 10 in.in diameter.Sockeye in sloughs also utilize a similar size range of sUbstrates.silt is not used nor is sand.Chinook salmon spawn in tributaries and most often utilize rubble (3-5 in.diameter)and cobble (5-10 in.).Based on literature review and extrapolation from othE~r river systems,AD&FG (Vincent-Lang et a1.1984)indicates that pink salmon utilize substrates from small gravel (l/SI-l in.in diameter)to rubble (3-5 in.)with large gravel (1.-:3:in.)being preferred.Using a similar method of analysis, Vincent-Lang et a1.(1984)found that coho would mainly use small (1/8 to 1 in.)to large (1-3 in.)gravel. 90 r - - 4.2.4 Streamflow (i.)High Streamflow Du.ri.ng periods of high streamflow,McNeil (1969)found that disappearance of embryos due to streambed scouring often exceieded 50 percent for chum and pink salmon eggs and alevins in streams that he studied in southeast Alaska.On one occasion,McNeil recorded a loss that exce4?ded 90 percent. High flows can also cause deposition of fine sediment on the redds,which can reduce permeability or entrap emerging fry (Hale 1981). A clear definition of the flows that result in loss is ill-defined because moderately high flows may be beneficial in assuring adequate interchange of intragravel and surface waters and improving the oxygen supply to embryos (Reiser and Bjornn 1979)and,depending on conditions,may remove fine sediments. In general,velocities should be less than those ,that displace spawning bed materials (Reiser and Bjornn 1979). In t.he Susitna River and its tributaries,high streamflows and bed lmaterial movement predominantly occur during the open water seaSI:)n either due to high discharge from rain events or ice/:snow melting.Increases in streamflow in side channels and slou<;Jh habitats can also occur during the ice covered period, when ice jams and staging cause overflows from the mainstem (R&M Consultants 1984).The mainstem bed material appears to be rl~latively stable compared to side channels and sloughs. (ii)Low Streamflow - Once embryos have begun incubation,reductions in lead to dessication of embryos,low oxygen tempE~ratures,or during cold weather,freezing 91 discharge can levels,high (Hale 1981). - - McNedl (1969)found that freezing could be a cause of high mc)rt:ality,but that its occurrence was erratic in streams that he s~tudied in southeast Alaska. Responses of incubating embryos and behavioral characteristics of cr:llevins to dewatering have been studied by Stober et al. (19c~2)on the Skagit River,Washington.Using chinook,chum, cohe),and pink embryos,the authors found that various periods of daily dewatering (with maintenance of humidity and temperature)for up to 24 hrs per day in several substrate type~s maintained prehatching survival for all species with a de:cI"ease in post-hatching survival in direct relationship to th.e length of daily dewaterings.Also,tolerance to single dewa,tering events of various times decreased as development of alevins progressed.Stober et al.(1982)qualified these resullts to state that they should be used cautiously during extrapolation to field conditions.such extrapolation would probably not be valid for the severe conditions (particularly cold)that occur on the Susitna River.The I Skagit River studies do point out,however,that alevins have some ability to avoid severe conditions by moving through the gravel. 4.2.5 Superimposition Superimposition can occur if salmon excavate existing redds that were developed by previous spawners.In addition to mechanical injury that can occur,existing embryos can be removed from the redd,thus exposing them to light (which can kill incubating embryos)and predators.Superimposition becomes more prevalent when the density of spawning adults incr,eases.No specific studies have been undertaken to determine effects of superimposition on the Susitna River. However,because competition exists both within and between salmlon species in certain limited areas of spawning (e.g., sloughs),it is suspected that superimposition does occur. 92 - 4.2.6 Predators on Live Eggs Numerous species of predators can consume live eggs.McNeil (1969)suggests that sculpins (Cottus sp.)and possibly other fish predators may be involved.Poten.tial predators;such as rainbow trout and Dolly Varden,are present in the Susitna River,but no information is availablE~on the effects of egg and embryo predation. 4.3 JUVENILE SALMON 4.3.1 Sockeye Salmon (1')Emergence The emergence of sockeye salmon in the Talkeetna-to-Devil Canyon reach (RM 98.6-152)occurs during the month of March (ADF&G 1983b,c)•In late April most:sockeye juveniles of age 0+have reached 33 mm in length.This obse~ed emergence timing is similar to the April to June emergence reported for sockeye by Morrow (1980)and Scott and Crossman (1973). (ii)Seasonal Movements In other river systems,sockeye usually·spend one to two years in lakes before going to sea (Morrow 1980,Scott and Crossman 1973).However,in the Talkeetna-to-:Oevil Canyon reach (RM 98.6-152),suitable lakes are not available for rearing sockeye.Therefore,juvenile sockeye either rear in sloughs or leave the Talkeetna-to-Devil Canyon reach during their first year of life (ADF&G 1984b).It is unknown if the age 0+ sockeye leaving this reach of river go directly out to sea as smolts or move to rearing habitats in lother sub-basins of the..,.. Susitna river.If they do go directly to the ocean,their survival is low (ADF&G 1981a,1982a;Barrett et ale 1984, 1985). 93 For those juvenile sockeye that rear and overwinter in the Talkeetna-to-Devil Canyon reach,upland sloughs and side sloughs are used most frequently.In 1982,over 90 percent of the 1325 juvenile sockeye collected ~tlere in upland and side slough habitats (ADF&G 1983b)•Similarly ,in 1983 densities were highest in side slough and upland slough habitats (Schmidt et al.1984).In 1983 rearing sockeye were about equally distributed between upland slough and side slough habitats (Figure 23).The most important Uplal'lld slough was Slough 6A, while Slough ~~was the most important side slough. The importance of Slough ~1 for rearing sockeye is likely due to two factors.First,Slough 11 is an important slough for sockeye spawning,accounting for over 75 percent of the total slough escapement for adult sockeye salmon in 1982 (Barrett et al.1984).And secondly,Slough 1~i13 breached only at high discharges (over 42,000 cfs)(Sautnelc et al.1984).This condition provides more favorable rearing conditions than breached sloughs.There have been decreased catches in natal side sloughs after breaching transforms the side slough to side channel habitat (Schmidt et al.1984). During July and August 1983 there was a redistribution of juvenile sockeye from natal side slc>ugh habitat to upland slough habitat (Schmidt et al.1984).Slough 6A was the most important upland slough for juvenile sockeye in 1982 and 1983 (ADF&G 1983b,Sch~idt et al.1984).This slough has low water velocity,clear water,adequate depth and abundant cover and is P quite different from the majority of sloughs in the Talkeetna- to-Devil Canyon sub-basin (Schmidt et al.1984). Some juvenile sockeye overwinter in the Talkeetna-to-Devil Canyon sub-basin.This has been docume:nted by winter sampling and the downstream outmigrant trap cat,ches of age 1+fish at RM 103 (ADF&G 1983b,Schmidt et a1.1984).However,catches of age 1+sockeye have been low (less 1:han 1 percent of the 94 ----,'c_~1 -"~~~--1 1 J J I }l Slough 20 Maln,t.m II S'VIn Maln,t.m SU ..Combin.d Nin.Slough, Combin.d \0 Ul SIDE SLOUGHS TRIB UTAR I ES O.S-/. ~ MAINSTEM 51 DE CHANNELS Slough 198.4-'_ UPLAND SLOUGHS COMBINED MACROHABITAT TYPES DISTRIBUTION OF JUVENILE SOCKEYE SALMON BY MACROHABITA T TYPE ON THE SUSITNA RIVER BETWEEN THE CHULITNA RIVER CONFLUENCE AND DEVIL CANYON,MAY THROUGH OCTOBER 1983. PERCENTAGES ARE BASED ON MEAN CATCH PER CELL.(SOURCE:SCHMIDT et a!.1984) ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 23 Woodward.Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SU8ITNA JOINT ·VENTURE - - I""'" I I I r outmigrant trap catches),which indicates that this reach of river is not used extensively for overwintering.Age 1+ sockeye have been observed in sloughs 9 and 11 (Schmidt et ale 1984)• (iii)Food Habits Juvenile sockeye food habits were exan1ined in July and August 1982 at sloughs SA and 11 (ADF&G 19 R 3b).Fish were found to be feeding primarily on chironomid larvae,pupae and adults. However,dominance of food items is based on numbers not biomass or volume.Since chironomids are small,their volumetric contribution may.be overemph.asized by the numerical method.Electivity indices suggested a positive selection for chironomid larvae.Cladocerans and clopepods were important food items of juvenile sockeye in Slough 11 during August.A variety of aquatic and terrestrial insects were also consumed. (iv)outmigration Timing Most juvenile sockeye salmon leave the Talkeetna-to-Devi1 Canyon reach (RM 98.6-152)during their first year of life. Over 99 percent (12,312)of the 12,395 juvenile sockeye caught in outmigrant traps at RM 103 in 1983 were age 0+fish,while only 83 fish were age 1+(Schmidt et ale 1984).If age 0+ sockeye go directly to the ocean their s;urvival is low,because less than one percent of returning cldult sockeye at Curry station (RN 120)outmigrated as age 0+s;molts (ADF&G 1982a). The peak outmigration of age 0+sockE~ye at RM 103 occurred during ear:y July in 1982 and 1983 (ADF~tG 1983b,Schmidt et ale 1984)(Figure 24).The outmigration was monitored from mid-June to mid-October in 1982 and fro:m mid-May to the end of August in 1983 (ADF&G 1983b,Schmidt et ale 1984).Catches of age 0+sockeye occurred throughout the sampling season.The 96 10 9 8 '"""II:1 5 %:, II:....5a. 18 Z3 28 2 1 12 11 22 11 2 "7 12 11 22 21 I 6 II 16 21 26 !---Il4AY-+I---JUN[----+ot----J'IJ1.T----j...--AUGUST---! DATE .CHUM SALMON FRY DAILY CATC::H PER HOUR RECORDED AT THE DOWNSTREAM MIGRANT TRAPS,MAY 18 THROUGH AUGUST 20,1983. (SOURCE:SCHMIDT et al.1984)' 12122211232a l--....AY'-+-----JUN[-+JUl..l--_-+o AUGUST ____' ,~~~. I I I j I I I I i 11'22 21 I 6 II 16 21 26 ]I 16.5 ISO 13.5 12.0 ~10,3 0 %:90 II: 1.1.1 15a. ::c 60to) ~c to) OATE SOCKEYE SALMON FRY DAILY c::::ATCH PER HOUR RECORDED AT THE DOWNSTREAM MIGRANT TRAPS,MAY 18 THROUGH AUGUST 30, 19 83.(SOURCE:SCHMIDT et al.1984)' ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 24 Woodward-Clyde,Consu Itants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE 97 - outmigration of age 1+sockeye occurrE~d primarily during May and June and was over by the end of July in 1982 and the end of June in 1983. - Analyses were done to compare 1.983 juv{:.nile sockeye outmigration catch rates at RM 103 with mainstem discharge (Schmidt et ale 1984).The coefficiel:'lt of determination (r2 ) between mainstem discharge and outmigration rate was 0.12 for age 0+fish and 0.06 for age 1+fish. r-(v)Size r The average size of outmigrating age 0+sockeye in 1982 at RM 103 was 42 mIn in late June and incr,eased to 72 mm by early October (AOF&G 1983b).Age 1+sockeye in 1982 averaged 77 mm in early June and 87 mm in late July.In 1983 age 0+and 1+ fish were separated by length analysis..In early May age 0+ sockeye were less than 56 mm,while agle 1+·fish were 56 mm or greater.In lat,e June age 0+sockeye were less than 71 mIn, while age 1+fish were 71 mIn or greater (Schmidt et ale 1984). (vi)Population Estimates In 1983 the population size of age 0+sockeye was estimated in the Talkeetna-to-Oevil Canyon reach (E~98.6-152)•Fry were fin clipped and tagged with half-length coded wire tags at sloughs 8A,11 dnd 21 and recaptured in downstream outmigrant traps at RM 103.The popUlation size was an estimated 560,000 fish using the Peterson mark/recapture estimator and 575,000 fish using the Schaefer estimator (Schmidt et ale 1984). In 1983 survival estimates for egg to fry were calculated by dividing the fry popUlation estimate by the total potential egg deposition.survival from egg to fry was about 40.9 percent using the Peterson estimate of popUlation size and 42.0 percent using the Schaefer estimate of populaticm size (Schmidt et ale 1984)• 98 ~, f"'" I The high survival rate (41-42 percent)for egg to outmigrant for juvenile sockeye in the Talkeetna-i:o-Devil Canyon reach is not comparable to survival estimates for egg to fry in other studies (Schmidt et ale 1984).The study in the Susitna River covered a shorter period of ti::.'e (egg tiD age 0+sockeye),while other studies (Russell 1972 and Meehan 1966,cited in Schmidt et ale 1984)reported survival estimates of 0.6 to 8.5 percent from egg to age 1+or age 2+sockeye smlDl ts. 4.3.2 Chum Salmon (i)Emergence Chum salmon emergence in the Talkeetna-to-Devil Canyon reach (RM 98.6-152)occurred during 1982 in late February and March (ADF&G 1983b,c).By late April most j',ilvenile chum were 35 mIn in length.ThUS,it appears that chum salmon emergence occurs in this reach of the Susitna River from February through April. (ii)Seasonal Movements After emergence chum salmon may outmigrate to the estuary in a single night if.they are in systems cllose to the ocean (Scott and Crossman 1973).However,in other situations the chum outmigration may last for days or weeks (Morrow 1980). Most juvenile chum in the Talkeetna--to-Devil Canyon reach (RM 98.6-152)emerge by late April,while the peak outmigration (at RM 103)does not occur until early June or early July (ADF&G 1983b,c;Schmidt et ale 1984)II This indicates that juvenile chum from this reach c.'=the Susit"na River may spend one to three months rearing in freshwat.er.All juvenile chum in the Susitna River outmigrate as age 0+fish (ADF&G 1981a,b; 1982a;1983b;Barrett et ale 1984;Schmi.dt et ale 1984). 99 r r I Almost all juvenile chum (over 90 percent)were distributed in side slough and tributary habitats in the Talkeetna-to-Devil Canyon reach during 1983 (Figure 25).These side sloughs and tributaries were the same areas of adult chum spawning in 1982 (ADF&G 1~82a).Slough 21 supported 'the highest density of juveniles in side sloughs in 1983 while Indian River had the highest density of juveniles in tributaries (Schmidt et ale 1984). In early June 1983 juvenile chum densities dropped in side slough and tributary habitats and increased at side channels, upland sloughs and the downstream outJnigrant traps at RM 103 (Schmidt et ale 1984).Most juvenile chum salmon leave the Talkeetna-to-Devil Canyon reach by mid-~Tuly (Figure 24). (iii)Food Habits The food habits of juvenile chum have I1l0t been examined in the Susitna River.However,juvenile chum spend ,one to three months rearing in the Talkeetna-t:o-Devil Canyon reach (RM 98.6-152)before outmigrating and c:an gain up to 27 DIm in length during this period (ADF&G 1983b)..Morrow (1980)reports that they may feed on chironomids and cladocerans.Food habitat studies of juvenile chinook,coho and sockeye in the Talkeetna-to-Devil Canyon sub-basin indicate that chironomids comprised a significant portion of the diet for these three species (ADF&G 1983b).It is expected that juvenile chum al$o feed on chironomids in this reach of river.other food items may be important. (vi)OU.-migration Timing "f" ! All juvenile chum salmon in the susitna River outmigrate to ocean in their first year of life.The outmigration from Talkeetna-to-Devil Canyon sub-basin 'was monitored by downstream outmigrant traps (RM 10~1)from mid-June 100 the the the to -1 SlouOh 8A SI..,.n SlouOh. Comblnld 2.~.,. S louOh 8 6.~·1. SlouOh 9 7.8·1.1~1 SlouOh II ~~1 ~J ~"------l --)1 j l -, MAINSTEM SIDE CHANNEL I-'o I-' SIDE SLOUGHS Four Trlbutorl .. Combinld 2.0·1. ChOU Cr ..k TR IBUTARIES COMBINED MACROHABITAT TYPES Wh I,kl"eree k Slough Slough 22 ~ tOO -I. SlouOh 6A UPLAND SLOUGHS Ellvln Moinstem S ifu Combined 95"1. ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT DISTRIBUTION OF JUVENILE CHUM SALMON BY MACROHABITAT TYPE ON THE SUSITNA RIVER BETWEEN THE CHULITNA RIVER CONFLUENCE AND DEVIL CANYON,MAY THROUGH OCTOBER 1983.PERCENTAGES ARE BASED ON MEAN CATCH PER CELL.(SOURCE:SCHMIDT et al.1984) FIGURE 25 Woodward.Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE - I' i F I mid-October in 1982 and mid-May to thl9 end of August in 1983 (ADF&G 1983b,Schmidt et al.1984).In 1982,the peak outmigration occurred on June 21,just three days after the trap began fishing.Therefore,it is possible that the peak outmigration occurred before June 18 in 1982.By mid-July 1982 almost 90 percent of the outmigrantl3 (754 chum)had been caught.No juvenile chum were cau~Jht at the trap after mid-August in 1982 (ADF&G 1983b).In 1983 the outmigration peaked between early June and early July.By mid-August all juvenile chum had left the Talkeetn2L-to-Devil Canyon reach (RM 98.6-152)(Figure 24). Analyses were done to compare 1983 juvenile chum outmigration catch rates with mainstem discharge (Schmidt et al.1984). During mid-May to mid-July (this period.accounted for over 98 percent of the catch at the downstream lnigrant traps)almost 80 percent of the variation in catch rates was accounted for by mainstem discharge.The coefficient of determination (r2 ) between mainstem discharge and juvenile chum outmigration rates was 0.79;r =0.89 (Schmidt et al.1984). (v)Size Most juveniles had reached a length of 35 mm by late April 1982 (ADF&G 1983b).The mean size of juvenile chum in the Talkeetna-to-Devi1 Canyon reach (RM 98.6-152)was 42 mm (length range 29-55 rom)during the first two weeks of July 1982 (ADF&G 1983b)• (vi)Population Estimates The population size of juvenile chum was estimated in the Talkeetna-to-Devil canyon reach (RM 98.6-152)in 1983.Fry were fin clipped and tagged with half-lEmgth coded wire tags at sloughs SA,9,11 and 21 and at Indian River.outmigrating fry were captured at downstream outmigran,t traps at RM 103 and 102 r- i I examined for marks.The population size was an estimated 3,322,000 fish using the Peterson mark/recapture estimator and 3,037,000 fish using the Schaefer estimator (Schmidt et al. 1984)• Survival estimates for egg to fry were calculated by dividing the population estimate by the total pCltential egg deposition. Survival from egg to fry was 14.1 per1cent using the Peterson estimate of population size and 12.9 peJ:cent using the Schaefer estimate of population size (schmidt:et al.1984).The survival rate (13-14 percent)for egg tC)fry for chum salmon in the Talkeetna-to-Devil Canyon reach is within the range (0.4-35.4 percent)of those reported from other studies (Schmidt et al.1984). Daily outmigration rates,population si~~e and recruitment rates of juvenile chum were estimated at Slough 11 in 1983 (Schmidt et al.1984).Fish were tagged with half-length coded wire tags and marked with Bismark Brown dye so that fish marked over a three day period could be separated upon recapture by the particular day they were marked.On day two of the experiment, the juvenile chum population size in Slc>Ugh 11 was an estimated 2,068 fish,the daily emigration rate was 32.7 percent of the population,and the daily recruitment (emergence)rate was 1.84 percent of the population (Schmidt et al.1984). r A comparison of data from the east bank outmigrant trap at RM 103 for 1982 and 1983 indicates that in 1983 juvenile chum catch rates were 2.3 times higher 1:han 1982 catch rates (Schmidt et al.1984).This relative abundance of juvenile chum corresponds with the pLrent spawner relative abundance. The 1982 chum escapement (29,400 fi.sh)at Curry Station (RM 120)was 2.2 times higher than the 1981 escapement (13,100 fish)(Barrett et al.1984). 103 - ~- "'I ~. I 4.3.3 Coho Salmon (i)Emergence Coho emergence likely occurs before May in the Talkeetna- to-Devil Canyon reach (RM 98.6-15:n as the downstream outmigrant traps (RM 103)began catching age 0+juvenile coho in mid-May 1983 (Schmidt et al.1984).However,the emergence likely extends over a considerable tim,e period,based upon the shorter lengths of fish observed in ,June and July 1981,1982 and 1983 (ADF&G 1981b,1983b;Schmidt et al.1984).Scott and Crossman (1973)also report that coho emergence can occur from early March to late July,depending upon time of spawning and incubating water temperatures. (ii)Seasonal Movements There is a pattern of downstream movement of juvenile coho throughout the summer in the Talkeetna-to-Devil'Canyon river reach (RM 98.6-152)(Figure 26).Some juvenile coho of all age groups (age 0+,1+,2+)leave the Talkeetna-to-Devil Canyon sub-basin (ADF&G 1983b,Schmidt et al.1984). Most juvenile coho (96 percent)were distributed in tributary, upland slough and side slough habita1:s in the Talkeetna-to- Devil Canyon sub-basin during 1983 (Figure 27).Important tributaries for juvenile rearing in 1983 were spawning areas for adult coho in 1982 (ADF&G 1982a).Whiskers Creek,Chase Creek and Indian River had the highest juvenile coho densities, based upon mean catch per cell,of 1:he tributaries in 1983 (SchmiCt et al.1984). Sloughs 6A and 5 were important upland sloughs for juvenile coho rearing,while Whiskers Creek Slough and Slough 8 were important side sloughs in 1983 (Schmidt et al.1984).The 104 .~.~.-....,'-J ~-~J ~-,-:-1 .-]-1 -.J --1 1 }E oJ J 10 .-COHO,AGE to I _.-COHO,AGE·I9I 8 0: ::>10 r 6 0: Wa.S- :I:4U f- <l'3f-'I u 0 VI -2 .1 4 JULY '1" DATE COHO SALMON AGE 0+AND AGE t OR OLDER DAILY CATCH PER HOUR RECORDED AT THE DOWNSTREAM MIGRANT TRAPS.MA Y 18 THROUGH AUGUST 30.1983.(SOURCE: SCHMIDT et a!.1984).r------------- ~I•I ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 26 Woodward-Clyde Consultants . and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE --1 --1 -J -}j I ) VI h ia k.n Creell S I aug h \ • ./EI.nn Slough .--..../Comb In.d 1.2 .,. Whlah,. Crull \ Slough Fourl ..n Mainal.m Sid. Chann.l,Combln.d O.D .,. Slaugh 194·'. ""''----/ '"AND SLOUGHSUPL SIDE SLOUGHS MAINSTEM SIDE ~~CHANNEL V.a .,.4.0·'.four Trlbutorl..1./ Combined 3.2·'.IndlonRlv.r 6.9·'. whhura ' Crull ...... o 0'1 COMBINED MACROHABITAT TYPES DISTRIBUTION OF JUVENILE COHO SALMON BY MACROHABITAT TYPE ON THE SUSITNA RIVER BETWEEN THE CHULITNA RIVER CONFLUENCE AND DEVIL CANYON,MAY THROUGH NOVEMBER 1983.PERCENTAGES ARE BASED ON MEAN CATCH PER CELL.(SOURCE:SCHMIDT et al.1984) ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 27 Woodward·Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE ~ I r presence of juveniles in these sloughs coupled with the infrequent catches in side channel habitat suggests that juvenile coho are found primarily in low-velocity,clear water areas.Upland and side sloughs may al~;o attract juvenile coho due to higher water temperatures (Schmidt et ale 1984). Significant overwintering of juv1enile coho in the Talkeetna-to-oevil Canyon reach occur:s in side sloughs and upland sloughs (Schmidt et ale 1984).In 1981 through 1983, Whiskers Creek Slough (side slough)and Slough 6A (upland slough)were used for overwintering by age 1+and 2+coho. Some coho may also use the mainstlsm,side channels and tributaries for overwintering. (iii)Food Habits Food habits were examined in August and September 1982 in the Talkeetna-to-Devil Canyon reach (RM 98.6-152).Chironomids were the dominant food item numerically in samp~es collected. Since chironomids are small,their vol'umetric contribution is probably less than their numeric cOlntribution.Electivity indices suggested a positive selection for chironomid larvae. other dipterans,and mayfly and stonefly nymphs were occasionally eaten.Riis and Friese (ADF&G 1978)found that juvenile coho in the Susitna River fed on drifting aquatic insect larvae in the spring,while the adult stage of aquatic insects were major food items during thE~summer and fall. Scott and Crossman (1983)report that :juvenile pink,chum and sockeye can be important food items for age 1+and older coho. These food :tems are more likely to occur in coho diets between May and August,when juvenile pink,chum and sockeye are more numerous in the Talkeetna-to-oevil Canyon sub-basin. 107 ,... r r 'I r (iv)outmiqration Timing The outmigration of juvenile coho from the Talkeetna-to-Devil Canyon reach (RN 98.6-152)was monitored by downstream migrant traps (RN 103)during 1982 and 1983 (;t1)F&G 1983b,Schmidt et ale 1984).There was a downstream movement of juvenile coho throughout the summer (Figure 26).Age 0+fish accounted for over 90 percent of the trap catch of 5;,646 coho,whil Ea age 1+ and 2+fish comprised the remaining portion (Schmidt et ale 1984). From November 1980 to May 1981 age 2+c«:>ho were captured in the Talkeetna-to-Devil Canyon reach (ADF&G 1981b).After May in this reach of river and mid-June in the Cook Inlet to Talkeetna reach no age 2+coho were caught.Catc:hes of age 2+coho were low at the outmigrant traps at RN 103,however it appears that catches peaked in early June in 1982 and 1983 (ADF&G 1983b, Schmidt et ale 1984).Analyses of scales in 1982 and 1983 from returning adult coho salmon at Curry s'tation (RMI120)indicate that most coho outmigrate from the Susitna River as age 1+or 2+smolts (ADF&G 1981a,1982a,Barrett et ale 1984). Analyses were done to compare juvenile coho outmigration catch rates at RM 103 with mainstem discharge (Schmidt et ale 1984). The coefficie~t of determination (r2 )between mainstem discharge and outmigration rates was 0 ..17 for age 0+fish and 0.22 for age 1+fish. (v)Size The average size of age 0+coho in the Talkeetna-to-Devil Canyon sub-basin (RM 98.6-152)was 56 mlm in late June 1981 and 41 rom in late June 1982.The size increased to 63 rom in late September in 1981 and 65 rom in late September 1982 (ADF&G 1981b,1983b).In 1983,age 0+coho wez:'e separated from age 1+ and older coho by length frequency and scale analyses~age 0+ 108 r I coho were less than 46 mm in early May,less than 66 mm in late June,and less than 96 mm in late September (Schmidt et al. 1984)• Length frequency and ;:;cale analyses oj:coho salmon cannot be used to separate age 1+and 2+coho because of overlapping lengths (ADF&G 1983b).Therefore,aHe 1+and 2+fish were combined as age 1+and older in most analyses (Schmidt et al. 1984)• (vi)Population Estimates Population size and survival estimates of juvenile coho have not been done in the Susitna River.Catches of juvenile coho in 1982 suggest that the river reach downstream of RM 98.6 is used more for coho rearing than the res\ch upstream of RM 98.6. About 80 percent of the 1,857 juvenile coho caught in 1982 were captured downstream of RM 98.6 (ADF&G 1983b). A comparison of data from the east bank outmigrant trap at RM 103 for 1982 and 1983 indicates that in 1983 juvenile coho catch rates were 2.8 times higher than the 1982 catch rates (Schmidt et al.1984).This relative abundance of juvenile coho corresponds with the parent spawner relative abundance. The 1982 coho escapement (2,400 fish)a1:Curry station (RM 120) was 2.2 times higher than the 1981 E!SCapement (1,100 fish) (Barrett et al.1~84). 4.3.4 Pink Salmon (i)Emergence The emergence of pink salmon probably oc:::curs in March and April in the Talkeetna-to-Devil Canyon reach (RM 98.6-152).Limited information obtained in 1981 indicated that fry appeared in Slough 11 and Indian River on April 11 (ADF&G 1981b). 109 r I r (ii)Seasonal Movements After emergence juvenile pink salmon move almost immediately downstream to the ocean (ADF&G 1981.b,1983b;Schmidt et al. J984).All juveniles in the Susitna River outmigrate in their first summer (age 0+fish)and little if any freshwater rearing occurs. Most juvenile pink salmon were captulred in the downstream outmigrant traps (RM 103)in May and June (Figure 28).In 1982,the downstream outmigrant trap caught only seven juvenile pink during early July (ADF&G 1983b).In 1983 the downstream outmigrant traps caught few juvenile pink after JUly (Schmidt et ale 1984). (iii)Food Habits It is uncertain if juvenile pink salmi::ln feed in the Susitna River.They apparently spend little time in the Talkeetna- to-Devil Canyon reach (RM 98.6-152)aftEtr emergence (Schmidt et ale 1984).Scott and Crossman (1973)indicate that juvenile pink salmon remain in freshwater for lsuch a short time that many do not feed at all.However,thc)se that migrate longer distances to the estuary may eat nYmphal and larval insects. It is likely that juvenile pink salmon in the Talkeetna-to- Devil Canyon sub-basin may feed occasionally on chironomid larvae and other aquatic insects during their outmigration. (iv)outmigration Timing After emergence in April and Ma~,juvenile pink move almost immediately downstream to the estuary.In 1983 juvenile pink catches were highest at the outmigrant,traps (RM 103)during late May and early June (Figure 28). 110 .~.-'i '---'-l -~J ).~» 1.0 3 8282324 29 3 8 !3 !8 I-MAY ~l"JUNE .1_JULY ~ o ,\.J \....-J '--I iii I iii I I 19 0.6 a: ::> 0:c 0.6 a: w Q.. 0.4 ::c 0 I- ~I c( ~0 0.2 ~ DATE PINK SALMON FRY DAILY CATCH PER HOUR RECORDED AT THE DOWNSTREAM MIGRANT TRAPS, MA Y 18 THROUGH JULY 8,1983.(SOURCE:SCHMIDT et al.1984) ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 28 Woodward-Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE Analyses were done to compare 1983 ju~reni1e pink outmigration :"'"'catch rates at RM 103 with mainstem discharge (Schmidt et a1. 1984)•During mid-May to mid-July about 30 percent of thervariationincatchrateswasaccountedforbymainstem I discharge.The coefficient of determinatio~(r2 )between mainstem discharge and outmigration raltes was 0.30;r =0.55 (Schmidt et ale 1984). (v)Size The average size of juvenile pink,bebween RM 79 and 136,was 36 mm (length range 29-43 mm)during late May to late July 1982 (ADF&G 1983b).No increase in size was observed between fish measured in May compared to those measured in July.However, the sample size was small (28 fish).It appears that juvenile pink grow little,if any,during their freshwater residence. (vi)Population Estimates No estimation of the population size of juvenile pink salmon in the Talkeetna-to-Devil Canyon reach (RM 98.6-152)has been done.Catches have been low for this species.In 1982,only six fish were caught in the downstream migrant trap (RM 103), while in 1983,245 juveniles were captured (ADF&G 1983b, Schmidt et al.1984). Adul t runs of pink salmon are numerically dominant in even years in the Susitna River,with even-year escapements about 10 times greater than odd-year escapement,s (ADF&G 1981a,1982ai Barrett et ale 1984,1985).The progeny of even-year pink salmon emerge and outmigrate in thE~following odd year. Therefore,the abundance of juvenile pink salmon is likely greater in odd years than in even years. r 112 4.3.5 Chinook Salmon (i)Emergence Most chinook salmon emerge from the gravel in tributaries of the Talkeetna-to-Devil Canyon reach (RM 98.6-152)in March or April (ADF&G 1983d).Juvenile chinook had emerged prior to mid-April in Indian River in 1981 (ADF&It;1983c). (ii)Seasonal Movements In.other river systems juvenile chinoc)k usually spend one or two years in freshwater residence befe>re outmigrating to the ocean (as age 1+or 2+smolts)(Scott and Crossman 1973,Morrow 1980)•Most juveniles in the Talkeetna-to-Devil Canyon sub-basin (RM 98.6-152)spend one year in freshwater before going to sea as age 1+smolts (ADF&G 19~3la,b;1982a,Barrett et ale 1984;Schmidt et ale 1984). One to two months after emergence 'there is a downstream movement of some juvenile chinook (age 0+)from areas of high post-emergent densities (natal tributaries)to rearing and overwintering areas (mainstem,side channels,side sloughs, upland sloughs and tributary mouths)(ADF&G 1981b,1983b; Schmidt et ale 1984).The downstream redistribution of age 0+ juvenile chinook has been observed in the Deshka River (RM40.6).by Delaney et ale (1981),in !1:ontana Creek (RM 77)by Riis and Friese (ADF&G 1978)and in tlle Little Susitna River (eight miles east of the Susitna Rivel:'mouth)by Delaney and Wadman (ADF&G 1979).Some juveniles move downstream and leave the Talkeetna-to-Devil Canyon reach.The downstream out~igrant traps (RM 103)in 1983 captured age 0+juvenile chinook throughout the season with a maj or peak catch occurring in r August (Schmidt et ale 1984). I 113 i""'" I I r Important rearing habitats for juvenile chinook are side sloughs,side channels,upland slough.s and tributary mouths (ADF&G 1981b,1983b;Schmidt et ell.1984)•Apparently juveniles prefer areas of moderate wat.er velocity and depth, and utilize turbidity for cover (Schmidt et a1.1984).These conditions are often present in side channels.Consequently, densities of juvenile chinook were highler in side channels than in side or upland slough habitats (Figu:l:"e 29). side sloughs,tributaries,the mainstem,and side channels are used by juvenile chinook for overwintering areas (ADF&G 1981b, 1983b;Schmidt et ale 1984).Side sloughs may attract overwintering juvenile chinook because of the warmer water temperatures that are associated with groundwater upwelling in sloughs (Schmidt et al.1984). In 1981 juvenile chinook were captured throughout the Susitna River from Alexander Creek (RM 10.1)upstream to Portage Creek (RM 148.8)(ADF&G 1981b):in 1982 fish were collected between Goose Creek (RM 73.1)and Portage C:l:"eek (RM 148.8)(ADF&G 1983b)•In both years juvenile chinook abundance was higher downstream of the Chulitna River (RM 98 ..6). (iii)Food Habits Juvenile chinook food habits were examined in August and September 1982 at sloughs 8A,11,20,21 and at Indian River and Fourth of July Creek (ADF&G 1983b).Fish were found to be feeding primarily on chironomid larvae,pupae and adults. However,dominance of food items was bSlsed on numbers and not biomass or volume.Since ,~hironomids are small,their volumetric importance may be overemphasized by the numerical method.Electivity indices indicated thLat juvenile chinook had a positive selection for chironomid lsLrvae.Terrestrial and .other aquatic insects were also eaten (.A.DF&G 1983b). 114 ~~'---,~1 1 )'1 Moln'tem II 9.3·/.Oxbow One Eight Siles \/8.2·'. Combined 4.0% Slough 22 Whisker,Creek Slough Side Channel 10 Oxbow One f 10.7·'. .-#--.SidlChonnl1 10 J 17.9·/. TWIlvl Sit.. Combined Slough 9 SIDE CHANNELS Slough 6A ,~6'~UPLAND SLOUGHS COMBINED MACROHABITAT TYPES SLOUGHS~SiDE Five Trlbutorles Comblnld 10.4% 48.4"10r ....(;,70)/ Portage I~dion Cree k R.ve r "-l// TR/8UTAR/ES ~ ~ 111 DISTRIBUTION OF JUVENILE CHINOOK SALMON BY MACROHABITAT TYPE ON THE SUSITNA RIVER BETWEEN THE CHULITNA RIVER CONFLUENCE AND DEVIL CANYON,MAY THROUGH NOVEMBER 1983.PERCENTAGES ARE BASED ON MEAN CATCH PER CELL.I (SOURCE:SCHMIDT et al.1984) ,I ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 29 Woodward-Clyde Consultants and ENTRIX,INC. HARZA-EBASCO SUSITNA JOINT VENTURE F"" I I r I r I r r (iv)outmigration Timing There is a downstream movement of age 0+chinook throughout the summer (mid-May through August)with a major peak occurring in August (Figure 30).These age 0+chinook likel~redistribute to rearing and overwintering areas downstream of RM 103. Age 1+chinook leave the Talkeetna-to-Devil Canyon sub-basin primarily in May and June (ADF&G 1983b).In 1983,the outmigration of age 1+chinook at RM 103 was over by mid-July (Figure 30).Age 1+chinook apparently leave the Susitna River by September as no age 1+juveniles wel:e captured between Cook Inlet and Talkeetna Station (RM 103)sLfter the end of August (1981b)• Analyses were done to compare 1983 juvenile chinook outmigration catch rates at RM 103 with mainstem discharge (Schmidt et ale 1984).The coefficient of determination (r2 ) between mainstem discharge and outmigra1l:ion rates,was 0.25 (r = 0.50)for age 1+fish and 0.19 (r =0.44)for age 0+fish. Thus 25 and 19 percent of the variatio,n in outmigration rates was accounted for by mainstem discharge" (v)Size Age 1+chinook averaged 90 mm in length during May and June in 1981 and 1982 (ADF&G 1983b).This is when most age 1+chinook leave the Talkeetna-to-Devil Canyon s111b-basin (RM 98.6-152). In this reach of the Susitna River,age 0+and age 1+chinook can be separated by length frequency analysis (Schmidt et ale 1984).In early May age 0+chinook upst:ream of RM 103 are less than 56 mm,in early June they are lE!SS than 71 mm,and in early July they are less than 81 mIn.After August 1 all chinook upstream of RM 103 are considered age 0+fish (Schmidt et ale 1984). 116 150 12.5- 10.0a: ::> 0:r; I n:1.5 wa. :I:u I-'I I-5.0- I-'et -...J U ~~4 I-CHINOOK,AGE tOl -·-CHINOOK,AGE -I .~--,~-l ))1 1 2~-·-'....\1\,I ~,.~.,.....-----.f\"~.i.)__Q"',<11'...~.Q_ 0-.r'I .,I . . I I '>I I I I I I I 18 26 3 II 19 21 lS 21 29 6 14 22 30 ~MAY .1.JUNE .1-JULY .,. OIlTE AUGUST .1 C ...·NOOK SALMON AGE 0+AND AGE 1+DAILY CATCH PER HOUR RECORDED AT THE DOWNSfREAM MIGRANT TRAPS.MAY 18 THROUGH AUGUST 30.1983.(SOURCE:SCHMIDT et at 1984): ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FIGURE 30 Woodward.Clyde Consul~ants and ENTRIX.INC. HARZA-EBASCO SUSITNA JOINT VENTURE Downstream of Talkeetna station (RM 103),it is not possible to separate age 0+and age 1+chinook fro,m length frequency data alone because of overlapping lengths of the two age groups. After September 1 all juvenile chinook downstream of RM 103 are considered to be age 0+fish (A~F&G 1981b). (vi)Populat1on Estimates No estimate of popu].ation size for juvenile chinook has been done in the Susitna River.In 1982 juvenile chinook abundance in the Talkeetna-to-Devil Canyon sub-basin was lower than in 1981 and 1983 (Schmidt et al.1984}.Comparisons of the catches at the east bank downstream migrant trap (RM 103) between 1982 and 1983 indicate that juvenile chinook abundance was over four times greater in 1983 'than for the same time period in 1982 (Schmidt et al.1984). 4.4 RESIDENT SPECIES 4.4.1 Rainbow Trout Rainbow trout occur throughout Canyon (ADF&G 1983b).upstream tributaries for spawning and occurs primarily in the mainstem the Suslitna Basin below Devil from Talkeetna,they mainly use rearin~J,while overwintering (schmidt et al.1984). r I, upstream of the·Chulitna River confluence (RM 98.6),rainbow trout move into tributaries to spawn in late May and early June (Schmidt et ale 1984).Whiskers Creek (RM 104.4),Lane Creek (RM 113.6)and Fourth of July Creek (F/M 131.1)are the major spawning areas in this r~ver reach,whereas the larger tributaries (Indian River and Portage Creek)are of lesser importance (Schmidt et al.1984).Both sexes mature by age 5+ (schmidt et al.1984). 118 ,.... r r r r There is a post-spawning movement from spawning areas to feeding areas (Schmidt et al.~984).These feeding areas may be located in the same tributaries in which spawning occurred, or in other tributaries and at tributary mouths (ADF&G ~983b, Schmidt et aL 1984).During August and september rainbow trout can be found in sloughs and at tJ:ibutary mouths that are occupied by adult salmon (ADF&G 1983b ' l Schmidt et al.1984). It is suspected that rainbo~trout feed on salmon eggs at these sites (Schmidt et al.1984). Juvenile rainbow trout rear mainly in tributaries (ADF&G ~983b, Schmidt et al.1984).Some juveniles also rear in the mainstem and sloughs,but the use of these habitats appears to be limited (ADF&G 1983b,Schmidt et al.1984).Fourth of July Creek (RM 131.1)is an important reaJ:ing area for juvenile rainbow trout (Schmidt et al.1984). In the fall,rainbow trout move out Clf tributaries into the mainstem to overwinter (ADF&G 1983b,Schmidt et al.1984).By early December in 1983,most radio-tagged rainbow trout were located in mainstem areas that were not influenced by tributary inflow (Schmidt et al.1984). Based on recaptures from three years c:>f tagging (1981-1983), the popUlation size of rainbow trout in the Talkeetna-to-Devil Canyon reach was estimated to be about 4,,000 fish.(greater than 150 mm in length)(Schmidt et al.1984).This estimate s~lould be viewed as an approximation because it does not account for annual recruitment,mortality or emigration (Schmidt et al. 1984)• 4.4.2 Arctic Grayling Arctic grayling are found throughout the Susitna Basin (ADF&G 1983b).In the Ta1keetna-to-Devil Canyon reach,Arctic grayling primarily use mainstem habitats for overwintering and 119 r tributaries for spawning and rearing (ADF&G 1983b,Schmidt.et al.1984). Upstream of Talkeetna,Arctic grayling move into tributaries to spawn in May and early June (ADF&G 1983b,Schmidt et al.1984). High catches occurred in Whiskers Creek Slough (RM 101.2),Lane Creek (RM 113.6),Fourth of July Creek (RM 131.1),Indian River (RM 138.6),Jack Long Creek (RM 144.5)and Portage Creek (RM 148.8)in 1982 and 1983 (Schmidt e~t al.1984).Although these tributaries have not been identified as spawning areas, they are likely candidates.Spawning may also occur in the mainstem.In 1983,it was suspected that spawning occurred at or near RM 150.1 (Schmidt et al.1984). After spawning,most adults and juveniles remain in tributaries or move to tributary and slough mouths until early September (ADF&G 1983b,Schmidt et al.1984).Some juvenile fish rear in mainstem areas (ADF&G 1983b,Schmidt et a1.1984).These juveniles may be displaced from tributary hal:;litat by the territorial behavior of older,larger fish (ADF&G 1983b, Schmidt et al.1984). Durinq September,Arctic qray1ing move into the mainstem from tributaries (ADF&G 1983b,Schmidt et a.l.1984).It is sus- pected that this movement to the mainstelJl is for overwintering, however specific areas have not been identified (Schmidt et al. 1984)•Some fish may use the larqer,deeper pools in Portage Creek for overwintering (Schmidt et al.'1984). 4 •4 •3 Burbot Burbot occur throughout the Susitna Riv4sr basin (ADF&G 1981d, 1983 b).Burbot appear to be more abunda,nt downstream from the Chulitna River confluence (RM 98.6)(Schmidt et at.1984). 120 r Burbot are associated almost exclusively with the mainstem and mainstem-influenced areas. Burbot apparently move to spawning areas in the winter and then disperse to feeding areas after spawn.ing is completed (ADF&G 1983b,Schmidt et ala 1984).Other than these migrations, burbot are generally sedentary (ADF&G 1983b).Burbot spawning takes place from mid-January to early February in mainstem- influenced areas (ADF&G 1983a,Schmidt et ala 1984).Tributary and slough mouths are thought to be important areas of spawning,as are mainstem areas with groundwater upwelling (ADF&G 1983a,Schmidt et ala 1984).Spawning areas have not been located in the Talkeetna-to-Devil ICanyon reach (Schmidt et ale 1984).Downstream of Talkeetna,the mouth of the Deshka River (RM 40.5)is a known spawning areia (ADF&G 1983a). Due to the limited catch data,juvel1ile rearing areas are unknown.It is suspected that j uven:Lle burbot rear in the mainstem,tributary and slough mouths,and clea~ater sloughs (ADF&G 1981d,1983b). In 1983,15 burbot were estimated to occur between RM 138.9 and 140.1 (Schmidt et ala 1984).This population estimate should be viewed as an approximation because fE!w fish were caught dur- ring this stUdy (Schmidt et ala 1984).However,it appears that the burbot population size in the middle Susitna River is low. 4.5 OTHER SPECIES 4.5.1 Round Whitefish Round whitefish occur throughout the Susitna River drainage (ADF&G 1981d).Downstream from Devil Catnyon,they appear to be 121 r more abundant in the middle river reacb (ADF&G 1983b).Within this reach,round whitefish are most numerous between RM 132.6 and 150.1 (Schmidt et al.1984). Round whitefish were found in tributaries c..nd sloughs more often than mainstem areas in 1982 and 1983 (Schmidt et al. 1984)•The mainstem is used for somE~spawning and juvenile rearing,and as a migrational corridor. During September,there is an upstrEaam migration of round whitefish that is thought to be associa'ted with spawning (ADF&G 1983b).This species spawns in the mainstem and at tributary mouths in October (ADF&G 1983b,Schmidt et al.1984).During 1981 through 1983,nine spawning areas 'l.I7ere identified upstream of Talkeetna.Mainstem sites were:RM 100.8, 102.0,102.6, 114.0,142.0 and 147.0 (Schmidt et al.1984).Round whitefish may also spawn in tributaries,such as :Indian River and Portage, Creek (Schmidt et al.1984). .r Juvenile round whitefish rear mainly in the mainstem and sloughs (ADF&G 1983b,Schmidt et al.1984).Slow velocities and turbid water are apparently preferred (Schmidt et al. 1984)•overwintering areas of round ~lhitefish have not been identified (ADF&G 1983b). 4.5.2 Longnose Sucker Longnose suckers occur throughout the Susitna Basin (Schmidt et al.1984,Sautner and Stratton 1984).They appear to be more abundant downstream of the Chulitna River confluence (RM 98.6) (Schmidt et al.1984).In the Talkeetna-to-oevil Canyon reach (RM 98.6-152),longnose suckers are primarily associated with tributary and slough mouths,although the mainstem is also used throughout the open-water season (ADF&G 1983b,Schmidt et al. 1984).The major overwintering and juvenile rearing areas of this species are unknown (ADF&G 1983b).The mouths of Trapper 122 r r Creek (RM 91.5)and Sunshine Creek and side channel (RM 85.7) are known spawning areas (AOF&G 1983b). 4.5.3 Humpback Whitefish ~ Humpback whitefish are found downstream of Devil Canyon between RM 10.1 and 150.1 (Schmidt et ale 1984).They appear to be more abundant downstream from the Chulitna River confluence (RM 98.6)(Schmidt et ale 1984).In the Talkeetna-to-oevil Canyon reach,tributary and slough mouths are used by adults - most frequently,with the mainstem serving mainly as a migrational corridor (ADF&G 1983b,Sch~~idt et a1.1984).Due to low catches of humpback whitefish,little is known of their overwintering,spawning and juvenile rearing areas (ADF&G 1983b,Schmidt et ale 1984).It is suspected that they spawn in tributaries during October (Schmidt et ale 1984). 4.5.4 Dolly Varden Dolly Varden occur throughout the Susitna Basin (Schmidt et ale 1984).In the Talkeetna-to-Devi1 Canyon reach,Dolly Varden are found primarily in the upper reaches of tributaries and at tributary mouths (ADF&G 1983b,Schmidt et al.1984).They apparently use the mainstem for overwintering (Schmidt et al. 1984).Spawning and juvenile rearing areas are suspected to be in tributaries (ADF&G 1983b).The po,pulation size of Dolly Varden in the Talkeetna-to-Devil Canyon reach appears tc be low and they are apparently more abundant downstream from the Chulitna River confluence (RM 98.6)(Scb~idt et al.1984). 4.5 5 Arctic Lamprey Arctic lamprey have been found in the:Susitna River as far upstream as Gash Creek (RM 111.5),however they are more abundant downstream of RM 50.5 (ADF&G 1.983b,Schmidt et al. 123 r 1984).Most fish have been found in tributaries and tributary mouths (ADF&G 1983b,Schmidt et ale 1984). 4.5.6 Threespine Stickleback Threespine stickleback have been caught:in the Susitna River as far upstream as RM 146.9,but they are more abundant downstream of the Chulitna River confluence (RM 98.6)(ADF&G 1983b, Schmidt et ale 1984).Spawning and juvenile rearing apparently occur in tributary and slough mouths;(ADF&G 1983b).Over- wintering areas of this species are unknown (ADF&G 1983b). 4.5.7 Bering cisco Bering cisco occur mainly downstream of the Chulitna River confluence (RM 98.6)in the Susitna River (Barrett et al. 1984)•In 1981 and 1982,the major spawning areas for this species were in the mainstem between PM 75 and 85 (Barrett et al.1984).In 1982,most spawning fish were age 5 that had gone to the ocean for rearing in their first summer (ADF&G 1982a). 4.5.8 Eulachon Eulachon occur in the Susitna River as far upstream as RM 50.5, but are more abundant downstream of RM 29 (Barrett et al. 1984).Because eulachon are not found in the middle reach of the Susitna River,they are not discussed in great detail. Information on preferred habitat and life history information can be found in reports by Barrett et al.(1984)and Vincent-Lang and Queral (1984).Eulachon enter the Susitna River in two runs (Barrett et al.1984).The first run enters the river during the last two weeks of May,while the second run follows during the first two weeks of June (Barrett et al. 1984)•Fish from both runs spawn in the mainstem (Barrett et al.1984).The first-run population size is likely several 124 r I. r I hundred thousand fish,while the second run is probably several million fish (Barrett et al.1984).:rn 1982,most returning adults were age 3 that had gone to the ocean for rearing in their first summer (ADF&G 1982a). 4.5.9 Sculpin Slimy sculpin occur throughout the Susitna River drainage (ADF&G 1981e,1983b).They are most abundant in tributaries and tributary mouths,although the mainstem is also used (ADF&G 1983b)•Sculpin in the Susitna Riv4er are sedentary with spawning,juvenile rearing and adult I1tlovements confined to a limited area (ADF&G 1983b).In addit:ion to slimy sculpin, other species of sculpin may occur in the lower Susitna River (ADF&G 1981d). 4.5.10 Lake Trout Lake trout occur throughout the Susit;na Basin t primarily in larger,deeper lakes.Occasionally thE~y can be found in the inlet or outlet streams of these lakes.Lake trout have not been captured in the mainstem-influence:d areas of the Susitna River below Devil Canyon (ADF&G 1981b,1983b;Schmidt et al. 1984)• 4.5.11 Northern Pike Northern pike were apparently illegally transplanted into several lakes in the Yentna River drainage (RM 28)during the 1950 l s (ADF&G 1981d).During 1981 one northern pike was captured in the susitna River at Kroto Slough (&~30.1)(ADF&G 1981d)• 125 r r r 4.5.12 Ninespine stickleback Ninespine stickleback are apparently raJre in the Susitna River. This species has been captured in the vicinity of the Deshka River (RM 40.5)(ADF&G Su Hydro,unpublished data). 126 r I r I r r r 5.0 SUMMARY OF HABITAT UTILIZATION 5.1 MAINSTEM AND SIDE CHANNEL HABITATS Mainstem habitat is comprised of those portions of the Susitna River that normally convey streamflclw throughout the year (Figure 2).Both single and multiple c:hannels are included in this habitat category.The mainstem is typically characterized by high water velocities and armored streambeds.Substrates generally consist of gravel and cobble size materials with interstitial spaces filled with a grout-like mixture of small gravels and sands.Suspended sediment concentrations and turbidity are high during summer dUE~to the influence of glacial melt-water.Streamflows recede in early fall and the mainstem clears appreciably in October.An ice cover forms on the river in late November or December and lasts until late April or May (Trihey 1982,ADF&G 1983e).. side channel habitat consists of those portions of the Susitna River that normally convey streamflow during the open-water season but become appreciably dewatered during periods of low flow (Figure 2).Side channel habitat may exist either in well-defined overflow channels,or in poorly defined watercourses flowing through partially submerged gravel bars and islands along the margins of the mainstem river.Side channels are characterized by sha.llower depths,lower velocities and smaller streambed materials than the adj acent habitat of the mainstem river (Trihey 1982,ADF&G 1983e). 5.1.1 Adult Salmon Five species of Pacific salmon utilize:the mainstem and side channels upstream of the Chulitna confluence (RM 98.6), primarily as a migrational corridor (ADF&G 1981a,1982a; Barrett et ale 1984,1985).Migrational periods for adults of each species are: 127 Sockeye Chum Coho Pink Chinook -July through mid-September: -mid-July through mid-September: -mid-July through mid-September: -mid-July through August;and -Ju~e through July. r -1 I 'i' 1 ,I . Escapement estimates based on 1981 through 1984 data indicate that the mainstem and side channels of:the Talkeetna-to-Oevil Canyon reach (RM 98.6-152)serve as'a lnigrational corridor for less than 5 percent of the total Susitna River salmon escapement (ADF&G 1981a,1982a;Barrett et al.1984,1985). Generally,the upstream migration of adult salmon corresponds with the summer high-flow season.However,peak river discharge events apparently cause slowed upstream movements of salmon until high flows subside (Figures 13,15,17,19,21). Slowed upstream migration was obser~ed in the Talkeetna- to-Devil Canyon reach at flows above 40,000 cfs at Gold Creek (RM 136.8)(Sautner et al.1984). Mainstem and side channel spawning upstream of RM 98.6 has been observed for sockeye,chum and coho salmon (ADF&G 1981a,1982a; Barrett et al.1984,1985).Chum SalmOJl apparently utilize the mainstem margins and side channels for spawning more than coho or sockeye do.Peak counts of chum salmon spawning in mainstem and side channel habitats were:14 fish in 1981,550 fish in 1982,219 fish in 1982 and 1,266 fish in 1984 (Table 14).Only five coho and 44 sockeye were observed spawning in mainstem and side channel habitats during 1981-1984.Most mainstem spawning has been observed in late August to mid-September.The armored streambed material,high water velocities and infrequent upwelling sites apparently limit spawning in mainstem habitat. In 1984,about 5 percent of the 68,750 salmon spawning upstream of RM 98.6 used the mainstem for spatwning (Barrett et al. 1985). 128 r I r r 5.1.2 Juvenile Salmon Juvenile salmon of all five species utilize the mainstem and side channels upstream of RM 98.6 as a migrational corridor. Addit.ionally,mainstem and side channels are important overwintering areas for chinook and coho,and summer rearing areas for chinook salmon.Periods of juvenile salmon mainstem and side channel use in the Talkeetna-to-Devil Canyon reach (RM 98.6-152)are outlined be19w. Sockeye -Juvenile sockeye use the mainstem and side channels mainly for movements and outmigration.During 1982 and 1983 most juvenile sockeye moved out of the Talkeetna-to-Devil Canyon reach during June and July (ADF&G 1983b,Schmidt et ale 1984)(Figure 24).Mainstem and side channel habitats are relatively unimportant rearing habitats for this species (Figure 23). Chum -Juvenile chum leave natal tributaries and sloughs in June and move into side channels and the mainstem (Schmidt et ale 1984).During 1982 and 1983 most juveniles had migrated downstream of RM 103 by mid-July (ADF&G 1983b,Schmidt et ale 1984)(Figure 24).Juvenile chum use mainstem and side chann,els for rearing in low densities (Schmidt et al.1984)(Figure 25). C'oho -Relatively few juvenile coho utilized mainstem and side channel habitats for rearin9 in 1983 (Figure 27). They use these habitats primarily as a migrational corridor and for overwintering.outmigration of juvenile coho peaked during June in 1982 and in June,July and August during 1983 (ADF&G 1983b,Schmidt et ale 1984) (Figure 26). 129 r I rI, Pink -Juvenile pink salmon use the mainstem and side channels mostly as migrational cor:l:'idors.Most fish moved downstream of RM 103 during Mi3.Y and June in 1983 (Figure 28).Minimal freshwater rtaaring and growth occurs for juvenile pink salmon because clf their short residence time (Schmidt et ale 1984). Chinook -Mainstem and side channels are important summer rearing and overwil",tering habitat.s for juvenile chinook (ADF&G 1981b,1983b;Schmidt et ale '1984)(Figure 29). Additionally,these habitats are used as migrational corridors.Most age 1+chinook m~/ed downstream of RM 103 in May and June in 1981 through lS183 (ADF&G 1981b,1983b; Schmidt et ale 1984),while age 0+,chinook moved downstream throughout the open water season/(Figure 30). Analyses were done to compare 1983 juvenile salmon outmigration rates with mainstem discharge (Schmidt et ale 1984).The correlation coefficient was highest f'or juveniJle chum (r = 0.89;r 2 =0.79),indicating that loutmigration rates for juvenile chum may be influenced by river discharge levels. Correlation coefficients were moderate t:o low for the remaining juvenile salmon and ranged from r =0.55 (r2 =0.30)for juvenile pink to r =0.24 (r2 =0.06)fClr age 1+sockeye. 5.1.3 Resident Species Most resident species migrational corridors. whitefish,also spawn et ale 1984). use the mainsteIll and side channels as Some species,such as burbot and round in these habitatsl (ADF&G 1983a,Schmidt The mainstem appears to be an important overwintering area for many resident fish.Rainbow trout,Arctic grayling and burbot apparently use the mainstem extensively during the winter (Schmidt et ale 1984).Other species,such as Dolly Varden, 130 r r whitefish,and suckers,likely,overwinter in the mainstem. However,overwintering areas have not bE~en identified for these species. Juvenile burbot,round whitefish and longnose suckers rear primarily in mainstem and side channel habitats (ADF&G 1983b, Schmidt et al.1984).Some Arctic grayling and rainbow trout juveniles also use these habitats (Schmidt et al.1984). 5.2 SIDE SLOUGH AND UPLAND SLOUGH HABlfJ~ATS The clear water in sloughs originatesfJ:~om local surface runoff and groundwater upwelling.Groundwater of 2-4 o C upwells in some slough channels throughout the ye!ar,thus keeping these areas relatively ice free in the winter.The shallow infiltration from the Susitna River is the primary source of the groundwater in many of the sloughs (APA 1984).Local runoff can be an important source of water for some sloughs in the summer. The stage in the mainstem controls the water surface elevation of the lower portion of the sloughs by forming a backwater that can extend some distance upstream irlto the slough.This backwater is divided into two parts-'-clear water from the slough and turbid water from the mainstem.At high mainstem discharges,the water level in the mouth of the slough raises and backs up the clear water in the slough.As th3 stage in the mainstem drops,the size and char2lcter of the backwater changes,reducing the depth of water a't the entrance to most sloughs. When high mainstem flows overtop the upstream (head)end of the sloughs,the flows flush out fine sediments that accumulate in the lower portion of the sloughs.;~s peak flows in the mainstem subside and the stage in the mainstem drops below the head of the slough,discharge through the slough drops and the water begins to clear,with sand in susplension settling out. 131 ----,--~- r r r-.. I Because of the diversity in the mClrphology of individual sloughs,the flows at which they are overtopped by the mainstem vary considerably.Most side sloughs are overtopped at flows between 15,000 to 25,000 cfs,although some sloughs are only overtopped at high discharge leve~s (e.g.Slough 11 at 42,000 cfs). In general,slough water temperatures eire warmer than ~mainstem water temperatures in the winter,due to the strong influence of groundwater upwelling in the sloughs.This may attract overwintering juvenile anadromous and resident fish to these areas (Schmidt et al.1984). Upland sloughs differ from side sloughs in that the upstream (head)end of the slough is rarely connected with the mainstem Susitna River or its side channels (Fi~~re 2).Upland sloughs are characterized by near zero velocities and an accumulation of silt covering the substrate resulting from the absence of mainstem scouring flows.Beaver activity is common in upland sloughs,and large backwater areas of the Susitna River. 5.2.1 Adult Salmon Sockeye,coho ,pink and chum salmon havE~been observed spawning in slough habitat in the Talkeetna··to-Devil Canyon reach (RM 98.6-152)(ADF&G 1981a,1982a;Barrett et al.1984,1985). Results of escapements and spawning surveys in 1981 through 1984 indicate that chum and sockeye are the most numerous salmon in sloughs while pink and coho are less abundant. Total slough escapements upstream of RM 98.6 for 1981 through 1984 are summarized below: 132 r Species 1981 1982 1983 1984 Average Sockeye 2,178 1,488 1,060 2,203 1,732 Chum 4,501 5,057 2,944 14,634 6,784 Coho °2 ° ° 1 Pink 38 297 °647 Odd-years 19 Even-years 472 In 1984,about 25 percent of all spawni.ng salmon (68,742 fish) upstream of RM 98.6 spawned in slough habitat (Barrett et ale 1985). Most slough-spawning salmon upstream of RM 98.6 spawn in August and September (ADF&G 1981a,1982a;Barrett et ale 1984,1985). During 1981 through 1984,spawning activity occurred mainly during the first three weeks of August.for pink salmon,the first week of September for chum salIll0n,and the first two weeks of September for sockeye (ADF&G 1981a,1982a;Barrett et ale 1984,1985). 5.2.2 Juvenile Salmon Sloughs are important habitats for juvenile Talkeetna-to-Devil Canyon reach (RM 518.6-152) serve as rearing and overwintering areas.The hab;tat by juvenile salmon ~s discussed below. salmon in the because they use of slough ,r Sockeye -Most sockeye rear in sloughs (Figure 23).Natal sloughs (8A,11 and 21)and upland sloughs are used most frequently.Some sockeye also ovel~inter in slough habitat (Schmidt et ale 1984). Chum Sloughs provide important rearing habitat for juvenile chum salmon (Figure 25).Chum salmon rear for one to three months before they move downstream as smolts. 133 Most juvenile chum leave the Tc:llkeetna-to-Devil Canyon reach by mid-July (Schmidt et ale 1984). Pink -The extent of slough utili.zation by juvenile pink is limited because they spend little time in freshwater (ADF&G 1983b,Schmidt et ale 19B4).Pink salmon natal sloughs are listed in Table 18. Coho -Some juvenile coho move fJ:~C"m natal tributaries to upland and side sloughs for rearing (Figure 27).Juvenile coho apparently prefer clear wab:ar and lower velocities (Schmidt et ale 1984).These conditions usually occur in upland sloughs more frequently than in side sloughs.Some juvenile coho use sloughs for overwintering. Chinook -Juvenile chinook used Iside sloughs and upland sloughs for rearing in relativel~r low densities in 1983 (Figure 29).However,sloughel apparently provide important feeding areas for juvenile chinook during the fall,salmon-spawning period.During the period,juvenile chinook move into sloughs to feed on salmon eggs (Schmidt et ale 1984).Sloughs may be important overwintering habitat for juvenile chinook. 5.2.3 Resident Species Sloughs are rearing areas for some resident fish.Rainbow trout,Arctic grayling and round whitefish use sloughs and slough mouths for rearing,while some burbot rear in slough mouths (Schmidt et ale 1984).These fish apparently feed on salmon eggs in-sl~ughs during the :salmon-spawning period. Spawning in sloughs by resident fish appears to be limited. Burbot and longnose sucker may spawn in slough mouths (ADF&G 1981a,1984b).The extent of overwi.ntering in sloughs by resident fish is unknown. 134 r 'I 5.3 TRIBUTARY AND TRIBUTARY MOUTH HABITATS Tributary streamflow,sediment,and theJ~al regimes reflect the integration of the hydrology,geolo~{,and climate of the tributary drainage (Figure 2).Hence,the physical attributes of tributary habitats are not dependent on mainstem conditions. Tributary mouth habitat extends from the uppermost point that the tributary is illfluenced by either the mainstem or the slough backwater to the downstream e:Ktent of the tributary plume (ADF&G 1981c).The tributary pl'arne is clearwater which extends downstream in the mainstem,:side channel or slough before mixing with the more turbid water.The extent of the plume is influenced by both mainstem and tributary flows.At higher mainstem flows,the plume is usucllly restricted.Depths and velocities in the plume are a~function of channel morphology and mainstem stage.Physic::al characteristics and fish utilization of tributary mouths arE~also influenced by the type of confluences:tributary/slough,tributary/side channel or tributary/mainstem (Sandone et al.1984).Water temperature and water quality are those of the tributary. 5.3.1 Adult Salmon r Tributaries serve as the primary spawni:ng habitat for chinook, coho and pink salmon (Barrett et al.1984,1985).About one-third of the chum salmon escapemeni:upstream of Talkeetna spawned in tributaries during 1984 (Barrett et al.1985). Tributaries are rarely used by adult sockeye salmon (Barrett et al.1984,1985). The peak counts in tributaries upstre2lm of RM 98.6 for 1981 through 1984 are summarized below: 135 r I r I Species 1981 1982 1983 1984 Average Chinook 1,121 2,474 4,432 7,180 3,802 Chum 241 1,737 1,500 3,814 1,623 Pink 378 2,855 1,329 17,505 Odd::'year 854 Even-year 10,180 Coho 458 633 240 1,434 691 Sockeye 1 4 1 13 5 In 1984,about 70 percent of all spawning salmon upstream of RM 98.6 (68,742 fish)spawned in tributaries (Barrett et al. 1985)• All five salmon species spawned in tributary mouth habitat in 1984 (Barrett et al.1985).Sockeye salmon spawning is limited in this habitat type (Barrett et al.1985).In contrast, chinook,pink,chum and coho salmon frequently spawned in tributary mouths in 1984 (Barrett et cll.1985).I Index counts of spawning salmon in tributary mouth habitats are unavailable, as counts are included in tributary clounts.It appears that more spawning occurs in tributaries than in tributary mouths (Barrett et al.1985).water depth and velocity may limit spawning in tributary mouths (Sandone et al.1984). 5.3.2 Juvenile Salmon The significance of tributary and tributary mouth habitats for juvenile salmon in the Talkeetna-to-Devil Canyon reach (RM 98.6-152)is discussed below. Sockeye Juvenile sockeye utilize tributary habitat incidentally (Schmidt et al.1984)"In 1983,few juvenile sockeye were captured in tributary habitat (Figure 23). Chum -Tributaries likely provide rearing habitat for chum salmon for about one to three l1:tonths (Schmidt et al. 136 r I :r 1984)•Tributaries upstream of RM 98.6 that are natal areas for juvenile chum are listed in Table 13. Coho -Tributaries serve as the :primary coho natal areas upstream.of RM 98.6.Some ~uveni.le coho use tributaries for rearing throughout the summer,while others redistri- bute downstream from areas of eme:rgence to other rearing habitats,including tributary mouths (Schmidt et al. 1984)•This redistribution occurs throughout the summer as fish become more mobile.Tributary mouths apparently provide important rearing areas for age 0+coho (ADF&G 1981b,1983b).Some of the largE~r tributaries,such as Indian River and Portage Creek,likely provide overwintering habitat for juvenile coho. Pink -Tributaries upstream of FlM 98.6 are the primary natal areas for pink salmon (Barrlatt et al.1984,1985). However,the extent of tributary utilization by juvenile pink is limited because they move downstream to the ocean shortly after emergence (Schmidt et al.1984). Chinook -Tributaries are import:ant rearing areas for chinook in the spring and early summer (Schmidt et al. 1984).The redistribution of some juveniles from tributaries to other rearing habitat,including the mainstem,sloughs and tributary m01uths,occurs throughout the summer (Schmidt et al.19 ~J4)•Tributary mouths apparently are important rearing areas for juvenile chinook.Tributaries,such as Indian River and Portage Creek,are likely utilized by juvenile chinook for overwintering. 5.3.3 Resident Species In the Talkeetna-to-Devil Canyon reach,tributaries are the primary spawning and rearing areas for l:~ainbow trout and Arctic 137 r "r r I r grayling (Schmidt et al.1984).The larger tributaries in this reach,such as Portage Creek,may provide overwintering habitat for some rainbow trout and Arctic grayling (Schmidt et al. 1984).However,it appears that overw'intering in tributaries is limited (Schmidt et al.1984). Round whitefish,humpback whitefish,DCllly Varden and longnose suckers likely spawn in tributary or t:ributary mouth habitats (ADF&G 1983b,Schmidt et al.1984).Juvenile Dolly Varden are thought to rear in the upper reaches of tributaries (Schmidt et al.1984).Tributary mouths are import,ant rearing and feeding areas for many resident species,such clS rainbow trout,Arctic grayling and whitefish (ADF&G 1981d,1983b;Schmidt et al. 1984). 138 r,, r r 6.0 FACTORS AFFECTING PRODUCTION Each life stage of fish has factors that may limit production. Some of these factors are complex and the mechanisms are not easily understood (e.g.,the relationships among food availability,growth,and survival).,In contrast,other factors are readily defined,such as freezing of redds causing direct mortality.Although biological organisms have the ability to adjust and adapt to various environmental conditions,overall they may not be highly successful.For example,survival of salmon eggs from deposition to fry emergence may be 5 percent or less under natural conditions • In contrast,survival rates of 95 pE~rcent,or greater occur frequently under artificially contrc)lled conditions (e.g. hatchery or laboratory conditions)that exclude many of the limiting factors.Following is a summary of the major limiting factors that may affect the freshwatE~r phases of anadromous salmonids in the Susitna River.Although specific studies may not have identified some of these as factors Ln the Susitna River,they have been described in other similar river systems. 6.1 ADULT SALMON When adult salmon enter the Susitna River,several potential situations can prevent them from succe:ssfully spawning.These include: (i)Sport Fishing the system. Susitna River -sportfish harvests remove fish The primary fishing effort in is for chinoo}~and coho salmon. from the The r \ effect of sport fishing is most evident on the coho salmon run.In 1983,almost one of every five coho entering the Susitna River "-I'as caught by an angler (Table 3).The extent of harvest is governed by regulations,water conditiolns,access to fishing sites,etc. 139 r f"" I I l\ t (ii)Predation -in areas where salmon are available, predators can remove adult,s prior to spawning. Alaska Department of Fish and Game personnel (1984a) have noted predation by bears,otter,weasels and eagles in the Susitna River,but this removal of fish is unquantified.Predation by animals is probably less significant than the effE~cts of sport fishing. (iii)Access -barriers to upstream ~igration such as Devil Canyon,impassable reaches in sloughs during low flow conditions and beaver dams can prevent fish from reaching spawning areas.It is unknown if this precludes successful spawning.Salmon strandings in passage reaches of sloughs,which can result in mortality,have been noted (Barrett et a1.1984). Additiona1 factors such as high or 10''''temperature extremes, low dissolved oxygen,and turbid waters have been implicated as potential factors limiting upstream migration,(Reiser and Bjornn 1979).However,these have not~been shown to prevent successful migration in the Susitna RivE~r,probably because the adults are exposed to ranges of these factors that are within their range of tolerance.Other factl:lrS such as high flows have been shown to result in cessaticm of upstream movement (Barrett et a1.1984,1985)(Figures 1:3,15,17,19,21),but movement does resume following thesE~events and fish do successfully move to their spawning sites.Therefore, mortality associated with high flow E~vents is likely not a significant factor. 6.2 SPAWNING AND INCUBATION Each species within the Susitna Basin c:haracteristica11y tends to utilize specific areas for spawning (see section 4.1).The lack of a particular type of area can limit production for a specific species. 140 I"'" I r \ r (v)Upwelling certain species,particularly chum salmon,seek areas of grollndwater upwelling for spawning and incubation (Vin.cent-Lang et al.1984, Barrett et al.1985).TheSE!areas offer potential temperature and flow benefits.BeCa\lse upwelling areas often support maj or spawning,it is assumed that areas lacking upwelling would likely limit the spawning and incubation success of species like chum salmon. (vi)Predation -Sculpins and oth~ar fish species such as Dolly Varden and rainbow trout have been implicated as taking significant numbers of salmon eggs.For example,Hunter (1959)found 1:hat,with pink and chum fry,the mor-tality from predat.ion could range from 23 to 86 percent.Predation on salmon eggs and embryos in the Susitna River has not been quantified. (vii)Low Streamflow -Low water call dewater spawning areas and expose incubating eggs and.alevins (McNeil 1969). Reduced winter flows may caUSEa significant mortality, if adult fish spawned under high water conditions and redds were located along the margins.This may have occurred during 1982 spawning and 1982-1983 incubation periods (Schmidt et al.1984).The occurrence of groundwater upwelling may reduce mortalities in areas of upwelling when natural flows in the Susitna River are lower during the winter. (viii)High Streamflow -Extremely high flows can scour redd~'and destroy eggs and alevins.High scouring flows are uncommon in fall and winter in the Susitna River.Thus,scouring is prc)bably not an important limiting factor. 142 r i (i,x)Freezing If redds are fJ:,ozen,mortalities will occur.Alevins may be able to move through the gravel to avoid adverse conditions.Freezing of redds is associated with low streamflows and sub-freezing temper?tures;'these conditions occur annually in the Susitna Riv,er.However,mortality due to frozen redds is unquantified in the susitna River.Dependence on upwelling areas by adult salmon may reduce embryo losses due to freezing. (x)Sedimentation -An influx of fine sediments can shut off the water flow through the substrate and result in increased mortality.Sedimentation of spawning areas in sloughs and side channels by high mainstem discharge,ice processes and local flows occur in the Susitna River.During spring breakup in 1982, Slough 9 suffered a heavy influx of silts and sands, reducing the amount of usable spawning habitat (ADF&G 1983a). (xi)Intraspecific Competition -l~dult salmon of the same species may compete for spec::ific spawning areas if the density of spawning adu11:s is high.competition for redd sites can lead to superimposition of redds (the excavation of existing redds).Based on egg retention studies,Barrett E!t al.(1984)concluded that the adult salmon density'was not excessive for chum salmon in slough habitats in 1983. (xii)Interspecific competition -Adult salmon of two or more species may compete for specific redd sites (e.g.chum and sockeye may utilize similar spawning habitats in sloughs).Thi.s can cause problems similar to those for intraspecific competition. 143 r r (xiii)Dissolved Oxygen -If sufficient dissolved oxygen is not present,growth of embryos can be retarded and mortality may occur.Dissolved oxygen is strongly tied to permeability of gravels and intragravel flow. Density of salmon eggs can also be a significant factor.If only a few eggsl are present,a given level of dissolved oxygen,intragravel flow,and substrate permeab~lity may be sufficient.At higher egg densities,this level might be insufficient and would cause poorly developed fry or,in severe cases, mortality.studies by ADF&G (1983a)have indicated that dissolved oxygen levels :Ln the Susitna River are generally not a problem for incubating embryos. (xiv)Ice Processes -In certain instances,staging due to ice cover can raise the level of the river diverting cold mainstem water (OoC)into sloughs that are predominantly supplied by warmer upwelling water (e.g.Slough 8A in 1982-1983;ADF&G 1983a).This can lead to reduced intragravel water temperatures,which can delay embryo development c,r cause mortality. 6.3 REARING Factors that limit the rearing phase of salmonids are complex and vary with species,size,and time of year.These factors may affect species fo~only a short period of time (e.g.,pink salmon fry may only be in freshwater for a few days before they outmigrate)or for more than a year (e.g.chinook,coho or sockeye juveniles).Following is a bri.ef summary of the major factors that affect rearing fish: (i)primary and secondary production -the amount of available food at specific times of the year can be 144 ---------------------------------------- r I critical to assuring the growth and survival'of rearing fish.In the Susitna River,the highly turbid water in the ice-free season reduces light penetration and primary production;primary and secondary production in the winter may be severely restricted by the ice cover and low levels of light. These,in turn,can severely reduce secondary production and potential sou:rces of fish food from within the system (atLtochthcmous production).The extent of either autochthonou!;or allochthonous (food sources from outside the syst:em such as insects that fall into the water)food pr,oduction in the Susitna River is presently unknown,although a study is currently underway to determine primary productivity relationships.Nutrients that support primary production may not be limiting in the Susitna River: extensive blooms of benthic algae have been noted during brief clear-water periods that occur prior to freeze-up. (ii)Water Velocity -This factor is important both for allowing production of fo()d organisms and for optimization of energy expellditures by fish.For example,fish will seek areas in which they do not have to needlessly expend energy.Low to moderate stream gradients and water velocities generally are considered productive juvenile rearing habitat (Canada Fisheries and Oceans 1980).Peak flow events that affect mainstem rearing areas may cause a downstream displacement of juvenile chinook (Schmidt et ale 1984). (iii)Water Depth -Small fish appeiar to utilize shallower areas with greater frequency.Unless too shallow to allow free movement,depth does not usually cause mortality in the Susitna River.Juvenile fish utilize water depth for cover in some situations. 145 ------_._-----_._-~--------------- r r r I ,...,. I - (iv)Substrate The number of benthic invertebrates generally decreases in the progression of rubble to bedrock to gravel to sand (Reiser and Bjornn 1979). This affects fish food production.Substrate also provides cover for juveniles and areas of decreased velocity.Cementing of interstitial spaces in mainstem and side channel substrates likely reduces their utility to rearing juvelniles. (v)Water Quality Temperature,dissolved oxygen, turbidity,pH and other water quality parameters can all limit production if they are not within a specific range.Even with this range,an optimum may not be available under natural conditions (e.g.an optimum temperature for growth of salmonids may be around lS o C,but temperatures do not reach this level in the Susitna). (vi)Cover Juvenile salmonidl;require,cover that provides protection from predators.Cover can include turbid water,vegetation,substrate and depth.Large substrates cmd turbidity commonly provide cover in mainstem and side channel habitats. Vegetation and organic debris provide cover in upland and side slough habitats. The end result of exposure to limiting factors in any system is the number of fish that are able to sur~ive and reproduce.The on-going studies to document the fish resources and habitats of the Susitna River are designed to establish these numbers. 146 r r \ - ACKNOWLEDGEMENTS Fundinq for this report was provided by the State of Alaska, Alaska Power Authority. The draft of this report was complet.ad when the author was employed by Woodward-Clyde Consultclnts.Two sUbsequent editions,the draft final and final reports,were done by the author as an employee of Entrix,.Inc.In the draft final and final reports,substantial revisions and additions were made: information on 1984 adult anadromous es~capement monitorinq was added,as were the sections on resident species,Berinq cisco and eulachon. The assistance of Don Beyer,Harzcl-Ebasco susitna Joint venture,in preparinq the sections on incubation and factors affectinq production is qreatly apprecic:s.ted. Thanks is extended to Rhonda Steward of Entrix,Ire.for typinq the many drafts of the manuscript,and Andrea Shoulders and Emily Berry of Woodward-Clyde Consult:ants for draftinq and preparinq the figures. staff of the followinq Proj ect participants provided helpful review comments: Alaska Department of Fish and Game,SU Hydro Alaska Power Authority Arctic Environmental Information and Data Center E.Woody Trihey and Associate!; Harza-Ebasco Susitna Joint vmlture R&M Consultants Woodward-Clyde Consultants 147 LITERATURE CITED Acres American.1983a.FERC applicatio:n for license for major project:Susitna Hydroelectric project,Initial statement Exhibit A,C,and D.Prepared for Alaska Power Authority,Anchorage,AX.Volume 1:189 pp. Acres American.1983b.FERC license application for major project:Susitna Hydroelectric Project,Exhibit E. Prepared for Alaska Power Autll0rity,Anchorage,AX. Volume 6A:Chapter 3.603 pp. Alaska Department of Fish Salmon Status Report. 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Aquatic Studies -Phase I Final anadromous fish study on the Prepared for Acres American,Inc. 148 1981a.SusitnaHydro Draft Report:Adul t Prepared for Acres Alaska Department of Fish and Game.1981c.Susitna Hydro Aquatic Studies Phase I Repclrt (Vol.1):Aquatic habitat and instream flow proj ect.Prepared for Acres American,Inc.BUffalo,NY.260 pp. Alaska Department of Fish and Game.1981d.Susitna Hydro Aquatic studies -Phase I Final Draft Report:Resident fish investigations on the Lower Susitna River.Prepared for Acres American,Inc.BUffalo,NY.166 pp. Alaska Department of Fish and Game.1981e.Susitna Hydro Aquatic studies Phase I R1eport:Resident fish investigations on the Upper SusitJ1a River.Prepared for Acres American,Inc.Buffalo,NY.137 pp. Alaska Department of Fish and Game.1982a.Susitna Hydro Aquatic Studies -Phase II Final Data Report:Volume 2. 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Neilson,J.D.and G.H.Geen.1981.l~numeration of salmon from spawner residence time and aerial Transactions of the American.Fisheries 110(4):554-556. spawning counts. Society. R&M Consultants,Inc.1982.Susitna Tributary Stability Analysis. American,Inc.BUffalo,NY.33 pp. Hydroe1ec~ric Project: Prepared for Acres +attachments. R&M ConSUltants,Inc.1984.Susitna RivEtr Ice study,1982-1983. Prepared for Alaska Power Authority.Anchorage,Alaska. 136 pp.+appendices. Reiser,D.W.and T.C.Bjornn. range land management on western United States and of anadromous sa1monids. Rept.PNW-96.54 pp. 1979.1:nf1uence of forest and anadromous fish habitat in the Canada.1.Habitat requirements USDA Forest Service Gen.Tech. Sandone,G.,D.vincent-Lang,and A.Hof'fman.1984.Chapter 8: Evaluations of Chum Salmon-spawning Habitat in Selected Tributary-Mouth Habitats of the Middle Susitna River.In Report No.3:Aquatic habitat and instream flow 153 investigations (May-October 1983]1,by C.Estes and D. Vincent-Lang,eds.Susitna Hydro Aquatic Studies.Alaska Department of Fish and Game.Anch.orage,AK.70 pp. sautner,J.S.,and M.E.Stratton.1984.Chapter 1:Access and Transmission Corridor Studies.In Report No.4:Access and transmission corridor investigations (July -October 1983),by D.schmidt,C.Estes,D.Crawford and D. Vincent-Lang,eds.Susitna Hydro ,Aquatic Studies.Alaska Department of Fish and Game.Anchorage,AK.89 pp. sautner,J.S.,L.J.Vining,and L.A.Rundquist.1984.Chapter 6:An Evaluation of Passage Cond,itions for Adult Salmon in Sloughs and Side Channels of the Middle Susitna River. In Report No.3:Aquatic habitat and instream flow investigations (May-october 1983),by C.Estes and D. Vincent-Lang,eds.Susitna Hydro ;~quatic Studies.Alaska Department of Fish and Game.Anchorage,AK.70 pp.and appendices. schmidt,D.,S.Hale,D.Crawford,and P.Suchanek,eds.1984. Report No.2:Resident and juvenile anadromous fish investigations (May-october 1983).Susitna Hydro Aquatic Studies.Alaska Department of Fil;h and Game.Anchorage, AK.395 pp. and E.J. Volume 19. Canada. scott,W.B. Canada. Ottawa, Crossman.1973.Freshwater Fishes of Fisheries Research Board of Canada Stober,.Q.J.,S.C.Crumley,D.E.Fast and E.S.Killebrew.1982. Effects of hydroelectric dischargu fluctuation on salmon and steelhead in the Skagit River,washington.University of Washington,College of li'isheries Conts.No. FRI-OW-8218. 154 Trihey,E.W.1982.Prelim.inary asseSSmelt'lt of access by salmon to side slough habitat abclve Talkeetna. for Acres American,Inc.Buffalo,NY.26 pp. spawning Prepared r(I Trihey,E.W.1983.Preliminary asseSSmelt'lt of access by spawning salmon into Portage Creek and Indi.an River.Prepared for Alaska Power Authority,Anchorage,AK.31 pp. Vincent-Lang,D.,A.Hoffman,A.E,ingham,C.Estes,D. Hilliard,C.Steward,E.Trihey and.S.crumley.1984. Chapter 7:An Evaluation of Chum and Sockeye Salmon ppawning Habitat in Sloughs and Side Channels of the Middle Susitna River.In Report l~o.3:Aquatic habitat and instream flow investigations (May -October 1983),by C.Estes and D.Vincent-Lang,eds.susitn~Hydro Aquatic Studies.Alaska Department of Fish and Game.Anchorage, AK.178 pp. Vincent-Lang,D.,and I.Queral.1984.Chapter 5:Eulachon I Spawning Habitat in the Lower Susitna River.In Report No.3:Aquatic habitat and instream flow investigations (May -October 1983),by C.Estes and D.Vincent-Lang, eds.Susitna Hydro Aquatic Studies.Alaska Department of Fish and Game.Anchorage,AK.32 pp.and appendix. Wangaard,D.and C.Burger.1983.Effects of various water temperature regimes on the egg and alevin incubation of Susitna River chum and sockeye ~lalmon.U.S.Fish and Wildlife Service,National Fishery Research Center, Anchorage,Alaska. 155 APPENDICES APPENDIX A -ADF&G susitna Hydro Reference List in Chronological Order 1.Barrett,B.M.1974.An assessmen11:of the anadromous fish populations in the upper Susi1:na River watershed between Devil Canyon and the Chulitna River. Division of Commercial Fisheries,Alaska Department of Fish and Game,Anchorage,l~.57 pp. r r I 2. 3. Friese,N.V.1975.Preauthorization assessment of anadromous fish populations of the upper Susitna River watershed in the vicinity of the proposed Devil Canyon Hydroelectric Project.Division of Commercial Fisheries,Alaska Department of Fish and Game. Anchorage,AX.108 pp. Alaska Department of Fish and Game.1977.Corps of I Engineers Susitna River llydroelectric Project: Baseline inventory study (1 July 1976-30 September 1976).Prepared for u.S.Depalrtment of the Interior, Fish and Wildlife Service,Anchorage,AX.91 pp. T 4.Riis,J.C.1977.Preauthorizatio~l Assessment of the Susitna River Hydroelectric Pz:'oject:Preliminary investigations of water quality and aquatic species composition.sport Fish Division,Alaska Department of Fish and Game.Anchorage,AX.50 pp. 5.Alaska Department of Fish and Giime.1978.PrC"'liminary environmental assessment of hydroelectric development on the Susitna River.Prepared for the u.s.Fish and Wildlife Service.Anchorage,AX.207 pp. 156 6.Alaska Department of Fish and Game. Aquatic Studies -Phase I Final anadromous fisheries project. American,Inc.Buffalo,NY. 1981.Susitna Hydro Draft Report:Adult Prepared for Acres 7.Alaska Depa.rtment of Fish and Game.1981.Susitna Hydro Aquatic Studies -Phase I Report:Resident fish investigation on the Upper Susitna River.Prepared for Acres American,Inc.Buffalo,NY.137 pp. 8.Alaska Department of Fish and Game.1981. Aquatic Studies Phase I Final Resident fish investigation on the River.Prepared for Acres American, NY.166 pp. susitna Hydro Draft Report: lower Susitna Inc.Buffalo, r T T 9.Alaska Department of Fish and Ganle.1981.Susitna Hydro Aquatic Studies -Phase I Report:Juvenile anadromous fish study on the Lower Susitna River.Prepared for I Acres American,Inc.Buffalo,NY.121 pp. 10.Alaska Department of Fish and Gaml!.1981.Susitna Hydro Aquatic Studies -Phase I Report (Vol.1):Aquatic habitat and instream flow Jproject.Prepared for Acres American,Inc.Buffalo,NY.260 pp. 11.Alaska Department of Fish and Game.19a1.Susitna Hydro Aquatic Studies -Phase I il:eport (Vol.2 Pt.1): Aquatic habitat and instream flow project.Prepared for Acres American,Inc.Buff'alo,NY.305 pp. 12.Alaska Department of Fish and GamEl.1981.Susitna Hydro Aquatic Studies -Phase I Report (Vol.2 Pt.2): Aquatic habitat and Instream J~low Project.Prepared for Acres American,Inc.Buffalo,NY.541 pp. 157 13.Alaska Department of Fish and Game.1982.Susitna Hydro Aquatic Studies -Phase I Rep4~rt:Aquatic Studies Program.Prepared for Acres ~~erican,Inc.BUffalo, NY.137 pp. 14.Alaska Department of Fish and Game.1982.Susitna Hydro Aquatic Studies -Phase II Fillal Data Report:Volume 2.Adul t Anadromous Fish S1:udies.Anchorage,AK. 239 pp. 15.Alaska Department of Fish and Game.1982.Susitna Hydro Aquatic Studies -Phase II RElport:Volume 2:Adult Anadromous Fish Studies,Pal:"t B:Appenqices A-H. Anchorage,AK.318 pp. 16.Alaska Department of Fish and GaDile.1983.Susitna Hydro Aquatic Studies -Phase II RElport:Summarization of Volumes 2,3 , 4 ;Parts I'and II ,and 5 -Su Hydro Basic Data Reports,1982.Pr'epared fo~Alaska Power Authority,Anchorage,AX.12Ei pp. 17.Alaska Department of Fish and Gam.!.1983.Susitna Hydro Aquatic Studies Phase II Data Report:winter aquatic studies (October,1982 May,1983), Anchorage,AX.137 pp. 18.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic Studies,'Phase II Report:SYnopsis of the 1982 aquatic studies and anal~rsis of fish and habitat relationships.Anchorage,Ak.152 pp. 19.Alaska Department of Fish and Game.1983.susitna Hydro Aquatic Studies -Phase II RE~port:Synopsis of the 1982 aquatic studies and anal~'sis of fish and habitat relationships.Appendices A-K.Anchorage,AK. 357 pp. 158 r T 20.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic Studies.Phase II Basic Data Report. Volume 3:Resident and jU1iTenile anadromous fish studies below Devil Canyon,1982.277 pp. 21.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic Studies.Phase II Basic Data Report. Volume 3:Resident and ju"enile anadromous fish studies below Devil Canyon,1982 (Appendices). 22.Alaska Department of Fish and Gam49.1983.Susitna Hydro Aquatic Studies:Phase IJC Basic Data Report. Volume 4:Aquatic habitat and instream flow studies, 1982,Part I and II.367 pp. 23.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic stUdies.Phase II Basic Data Report. Volume 4:Aquatic habitat andl instream flow studies, 1982,Appendix A (Draft).Anc~orage,~.182 pp. 24.Alaska Department of Fish and GamEl.1983.Susitna Hydro Aquatic studies:Phase II:Basic Data Report. Volume 4:Aquatic habitat andl instream flow studies, 1982,Appendix B (Draft).Anchorage,AK.99 pp. 25.Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic Studies:Phase II Basic Data Report. Volume 4:Aquatic habitat and.instream flow studies, 1982,Appendix C (Draft).Anchorage,AK.221 pp. 26.Alaska Dep~rtment of Fish and Gam~.1983.Susitna Hydro Aquatic Studies:Phase II Basic Data Report. Volume 4:Aquatic habitat and.instream flow studies, 1982,Appendices D and E (Draft).Anchorage,AK. 168 pp. 159 27.Alaska Department of Fish and Gam.e.1983.Susitna Hydro Aquatic Studies:Phase II Basic Data Report. Volume 4:Aquatic habitat and instream flow studies, 1982,Appendices F-J (Dri!ft)•Anchorage,AX. 236 pp. 28.Alaska Department of Fish and Game. Aquatic Studies Phase II Volume 5:Upper Susitna River 1982.Anchorage,AX.150 pp. 1983.Susitna Hydro Basic Data Report. impoundment studies, T 29.Barrick,L.,B.Kepshire and G.CW~ningham.1983.Upper Susitna River Salmon Enhancemlant Study.Division of Fisheries Rehabilitation,Enhc!ncement and Development,Alaska Department:of Fish and Game. Anchorage,AX.15 pp. 30.Barrett,B.M.,F.M.Thompson,and S.N.Wick.1984. Report No.1:Adult anadromous fish inyestigations (May-October 1983).Susitna Hydro Aquatic Studies. Alaska Department of Fish and Game.Anchorage,AX. 380 pp. 31.Schmidt,D.,S.Hale,D.Crawford,and P.Suchanek,eds. 1984.Report No.2:Resident:and juvenile anadromous fish investigationsl (May-October 1983). Susitna Hydro Aquatic Studies.Alaska Department of Fish and Game.Anchorage,AX.395 pp. 32.Quane,T.,P.Morrow,and T.Withrow.1984.Chapter 1: stage and Discharge Investigat:ions.In Report No.3: Aquatic habitat and instream :f:1ow investigations (May-October 1983),by C.Estes and D.Vincent-Lang, eds.Susitna Hydro Aquatic St~dies.Alaska Department of Fish and Game.Anchorage,AX.136 pp. and appendices. 160 33.Quane,T.,I.QUeral,T.Keklak,and D.Scagven.1984. Chapter 2:Channel Geometry Investigations of the Susitna River Basin.In Report No.3:Aquatic habitat and instream flow investigations (May-October 1983),by C.Estes and D.Vin1cent-Lang,ed~.Susitna Hydro Aquatic Studies.AlaskiCi Department of Fish and Game.Anchorage,AK.81 pp.and appendices. 34.Keklak,T.and T.Quane.1984.Chapter 3:Continuous water Temperature Investigations.In Report No.3: Aquatic habitat and instream :Elow investigations (May-October 1983),by C.Est~~s and D.Vincent-Lang, eds.Susitna Hydro Aquatic S1:udies.Alaska Department of Fish and Game.Anchorage,AK.112 pp. and appendices. 35.Sandone,G.and T.Quane.1984.Chapter 4:Water Quality Investigations.In Report No.3:Aquatic habitat and instream flow invElstigations (May-October I 1983),by C.Estes and D.Vinc::ent-Lang,eds.Susitna Hydro Aquatic Studies.Alaska Department of Fish and Game.Anchorage,AK.30 pp.and appendices. 36.Vincent-Lang,D.and I.Queral.1984.Chapter 5: Eulachon Spawn~ng Habitat in the Lower Susitna River. In Report No.3:Aquatic habitat and instream flow investigations (May-October 1983),by C.Estes and D. Vincent-Lang,eds.Susitna Hydro Aquatic Studies. Alaska Department of Fish and Game.Anchorage,AK. 32 pp.and appendix. 37.Sautner,J.S.,L.J.Vining,and L.A.Rundquist.1984. Chapter 6:An Evaluation of }>assage Conditions for Adult Salmon in Sloughs and Si.de Channels of the Middle Susitna River.In Repclrt No.3:Aquatic habitat and instream flow invE!stigations (May-October 161 1983),by C.Estes and Hydro Aquatic Studies. Game.Anchorage,AX. D.Vin4:::ent-Lang,eds.Susitna Alaskl!l Department of Fish and 70 pp.and appendices. r 38.Vincent-Lang,D.,A.HoffI1'~n,A.Bingham,C.Estes,D. Hilliard,C.Stewart,E.Trihlay,and S.Crumley. 1984.Chapter 7:An Evaluation of Chum and Sockeye Salmon Spawning Habitat in SlcJughs and Side Channels of the Middle Susitna River.In Report NO.3: Aquatic habitat and instream flow investigations (May-October 1983),by C.Est.~s and D.Vincent-Lang, eds.Susitna Hydro Aquatic S1:.udies.Alaska Department of Fish and Game.Anchorage,AX.178 pp. 39.Sandone,G.,D.Vincent-Lang,and 1~.Hoffman.1984. Chapter 8:Evaluations of Chum Salmon-Spawning Habitat in Selected Tributary··Mouth Habitats of the Middle Susitna River.In Repc)rt No.3:Aquatic habitat and instream flow invElstigation~(May-October 1983),by C.Estes and D.Vinc:ent-Lang,eds.Susitna Hydro Aquatic Studies.Alask2L Department of Fish and Game.Anchorage,AK.70 pp. r ,I 40. 41. Vincent-Lang,D.,A.Hoffman,A.Bi.ngham,and C.Estes. 1984.Chapter 9:Habitat Sui.tability criteria for Chinook,Coho,and pink Salmo~L Spawning in Tributaries of the Middle Susitna River.In Report No.3:Aquatic habitat and instream flow investigations (Kay-October 1983),by C.Estes and D. Vincnet-Lang,eds.Susitna Hy'dro Aquatic Studies. Alaska Department of Fish and Game.Anchorage,AK. 61 pp.and appendices. Sandone,G.and C.Estes.1984.Chapter 10:Evaluations of the Effectiveness of Applying Infrared Thermal Imagery Techniques to Detect Upwelling Groundwater. 162 r r In Report No.3:Aquatic habitat and instream flow investigations,by C.Estes alrld D.Vincent-Lang,eds. Susitna Hydro Aquatic studies.Alaska Department of Fish and Game.Anchorage,AK.27 pp. 42.sautner,J.S.and M.E.stratton.1984.Chapter 1: Access and Transmission Corricior Studies.In Report NO.4:Access and transmissic)n corridor investigations (July-October 1983),by D.Schmidt,C. Estes,D.Crawford and D.Vinc:ent-Lang,eds.Sus i tna Hydro Aquatic Studies.Alaskn Department of Fish and Game.Anchorage,AK.89 pp. 43.Schmidt.D.C.and M.E.stratton.1984.Chapter 2: PopUlation Dynamics of Arctic Grayling in the Upper Susitna Basin.In Report NO.4:Access and transmission corridor investigations (July-October 1983),by D.Schmidt,C.Estesl,D.Crawford and D. Vincent-Lang,eds.susitna H~'dro Aquatic Studies. t Alaska Department of Fish and Game.Anchorage,AK. 26 pp. 44.Alaska Department of Fish and Game.1984.susitna Hydro Aquatic Studies:Procedures )J[anual,May 1983 -June 1984.Prepared for Alaska POlr,irer Authority, Anchorage,AX.255 pp. 45 •Alaska Department of F ish and GamE~.1984 •Sus i tna Hydro Aquatic Studies:Procedures !{anual,May 1983 -June 1984.(Appendices)•Prepalt:"ed.for Alaska Power Authority,Anchorage,Ak.1.19 pp. 46.Barrett,B.M.,F.M.Thompson,and S.N.Wick.1985. Report No.1:Adult anadromou.s fish investigations (MaY-October 1984).Draft.susitna Hydro Aquatic Studies.Alaska Department of Fish and Game. Anchorage,AR.177 pp.and appendices. 163