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Home My WebLink AboutAPA317.. 1 ',_- the Egg and Alevin Incubation of Susitna River Chum and Sockeye Salmon r"..Effects of Various Water Temperature Regimes onI,., lim'--1i.CJJ iOOiOOOiiiiii; 10 ~n~~;.! I''01=~I.'.-----0 II'i~"..L";~I-..0=,l> •0 ~~rnO_i g (,1\)_:~t L;_~~ -.....1\),,," I\)-~c <.0--e!rt"101 ii ~l to :. I , ~; David B.Wangaard Carl V.Burger TK ~a15 A2:3 no •.J17 -- US Fish and Wildlife Service National Fishery Research Center Alaaka Field Station. A nc h 0 r a·g-e •A'I a a k a - August 1983 ·~ ...... f"".t, i'.'.', "","., If'" ~. [t, .~ [": fll;l::3 [I'.,""- '-1.·,t ·...'r ,~. 12 .-"t: r'··-•.l·..'., I ' -,'i-' I.~ Abstract This study was conducted to assess the potential effects of water tem- perature alterations (resulting from proposed hydroelectric development) on inc~bating salmon eggs and alevins in the Susitna River,Alaska.Chum (Onaorhynahu8 keta)and sockeye (0.nerka)salmon eggs from Slough 11, Upper Susitna River,were collected and fertilized on site during three occasions in September,19S2.The eggs were incubated in a laboratory in four separate temperature regimes until alevins achieved complete yolk absorption.The four regimes were designed to simulate 19S2-S3 tempera- tures in:(1)the main-stem Susitna River;(2)Slough SA (a known spawning area);(3)a regime 1°C colder than in Slough SA;and (4)a constant 4°C.Average temperatures for the four regimes described above were 2.1,3.9,2.9,and 4.0°C,respectively. Complete yolk absorption was delayed by up to two months in the 2.1 and 2.9°C temperature regimes,as compared to the regimes having average temperatures of 3.9 and 4.0°C.However,no biologically meaningful dif- ferences were observed in the mean size (mm)of alevins reared in any of the four regimes at complete yolk absorption.Regression equations are presented to predict development rates as a,function of water tempera- ture.For convenience,these rates have been converted to the number of days required for Susitna chum and sockeye to hatch and to attain com- plete yolk absorption for a given average incubation temperature. ARtIS Alaska Resources Library &Information SerVices }lnchorage,AJaska -n< \L\~S _S~ 1\8.'3 V)D.'?:,1"T' Effects of Various Water Temperature Regimes on the Egg and Alevin Incubation of Susitna River Chum and Sockeye Salmon Introduction- Hydroelectric development projects are in the planning or construction_stage r in several Alaskan rivers.Construction of these dams and their resultingl:~ ''- .... -, I I . i ~lc l, reservoirs are known to alter the normal downstream water temperature regimes (Baxter and Glaude 1980).Thermal effects from dam and reservoir operation in Alaska should be most pronounced during the fall and spring when the river's natural rapid cooling and warming may be modified by reservoir discharges. Thus t salmon eggs and alevins incubating downstream of a hydroelectric project may experience alterations from historical water temperatures which t in Al aska t generally range from 0 to 8°C. Much research has been conducted on the incubation of salmon eggs.While it has been reported that temperature changes within the range 0 to SaC have a more pronounced effect on development rates than those between 5 and 10 G C (Barns 1967).little information is available on egg incubation in water temperatures less than 4GC (Dong 1981;Raymond 1981;Alderdice and Velsen 1978).There is a regional need for this information as Alaskan salmon often ~-[spawn in water temperatures approaching or less than 4°C.There is a specific .'-f"~' ~,\~~..,. need for this information for Susitna River stocks due to the hydroelectric dams proposed for the Susitna River at river miles 153 and 184. - 2 The Susitna River in southcentral Alaska (Fig.1)drains about 19.000 mil into ~Cook Inlet.It is the sixth largest drainage in Alaska and supports a fisheryl~ resource that includes five species of salmon and other resident species such [] I""" r;l~,~ as grayling (ThymaZZus arcticus)and burbot (Lota lata).Many studies have been undertaken to evaluate the potential impacts of Susitna River hydro- electric development on fish and wildlife.This study was designed to inves- tigate the incubation of eggs and alevins from two species of Susitna salmon -~under varying temperature regimes. f1l~ POTeIlTIAL gAM SITIIS \--'------ ,- c.. ~r'~: i'!- Li -t ~r'1 U /. ''- r"'" }; L -r' L Figure 1.The Susitna River in southcentral Alaska and the location of two sloughs (used by spawning salmon)in relation to proposed hydro- electric dam sites. ~~ro: I -.b. 3 ..... r~;~ ,t'!While expected post-project river temperatures have not been fully identified at this time,it is understood that water temperatures downstream,of the dams will be less than pre-project temperatures in the summer,and greater than rJ pre-project temperatures in the fall and early winter.To help predict the -E .-r: [J-ntj r'~ IL 1""'r i r~' It _I" IL.. effects of various fall/winter water temperature regimes on Susitna River salmon eggs,the U.S.Fish and Wildlife Service,National Fishery Research Center (NFRC)developed the following study objectives in cooperation with the Alaska Department of Fish and Game (ADF&G)and the Alaska Power Authority (APA): 1.Incubate salmon eggs and alevins under controlled conditions using four temperature regimes which simulate:(1)the main-stem Susitna; (2)a side-channel slough system;(3)a second slough system differing from the first by-1°C;and (4)a constant water temperature of 4°C. 2.Collect and spawn five to seven pairs of chum (Onaorhynahus keta)and sockeye (0.nerka)salmon from a slough in the Upper Susitna on three different dates which include their normal peak spawning period. 3.Provide data on time to egg hatching and complete yolk absorption in temperature units (TUs)and days for each species.Also,measure lengths and record weights of alevins at time of hatch and yolk absorption and record data on survival and abnormalities of alevins during development. 4.Develop these data into a final report to help planners predict how certain temperature regimes will affect egg incubation and alevin --~----:--:-'~-- ~,;;;";.'..~~ 4.- L [..;.."'..'.'•... " .~c J ".,-- ..- _. l ~.- ~[ -1·····.t.0 development of Susitna chum and sockeye salmon. This study was conducted by the NFRC,U.S.Fish and Wildlife Service,in cooperation with its Division of Ecological Services and ADF&G.Su-Hydro Divi- sion.Major funding was provided by APA. Materials and Methods Well water was plumbed into eight insulated waterbaths in the NFRC laboratory. Water temperature control was achieved in the baths (heating or chilling) before the water flowed into eight separate Heath incubators.Control and monitoring of the incubator water temperatures was possible from 0.5 to 12°C with O.loC resolution and ±O.3°e accuracy.Four temperature regimes,each with a replicate.were monitored with a lO-channel temperature data logger . The data logger provided hourly printouts of water temperature for all eight incubators.The average temperature for 24 hours was used to compute the . accumul ated temperature units (TUs)for each temperature regime.Thus,if eggs were incubating at an average 5°C for 10 days,they would accumulate ~O TUs. Incubators were modified prior to egg collections to prevent water from mixing between the two species under study since chum and sockeye salmon were' to incubate simultaneously in all eight incubators.These modifications ensured that two water lines from a common source each fed only four of eight egg trays in each incubator,thus providing the ability to incubate each -r!I species independently.Because each water line fed only four trays,tempera-..L 5 ,- ~IJ (J .- D :-~ t1l~-- tures did not vary more than O.l°C as water passed through the trays. Unusually low water levels resulted in an insufficient adult salmon escapement (for experimental collections)into Slough 8A (RM 125).This site was pre- viously chosen to represent the temperature regime of a typical side-channel slough and provide a location for collecting the experimental salmon stocks. Slough 11 (RM 135.3)had adequate chum and sockeye salmon escapements and provided an alternate site for the egg collections while temperature recording E equipment remained in Slough 8A.Thus,three egg collections were made from """'!F ..... ( chum and sockeye salmon at ,Slough 11 (Fig.1).For each species at least seven pairs (males and females)were spawned on September 3,9 and 15.Egg fertilization and handling procedures followed the recommendations of Leitritz and Lewis (1980).After eggs were fertilized and rinsed they were allowed to []water harden for one hour in an 18 L bucket filled with water from the slough. -:I' l -[ Surface water temperatures in Slough 11 ranged from 5.8 to 5.0°C at point measurements taken during the three egg collections.The fertilized eggs were f then transported to the NFRC laboratory in Anchorage.L Ie -"~The eggs were measured out volumetrically in the laboratory and distributedL into eight equal lots.Each lot of eggs was allowed to acclimate to the incubating water temperature for one hour,before the eggs were placed into incubator trays.Eggs were placed into plastic rings (10 cm diameter x 5 cm depth)which were surrounded by styrofoam within the incubator trays.The styrofoam directed water flow through the rings where eggS (average 4.6 ml eggs/cm 3 ring volume)were held until hatching.Water flow was maintained at about 2.2 L/min throughout the study.Eggs were generally placed into the r-incubator trays within 10 hrs of fertilization.Dissolved oxygen was measuredL ·~f~L~ 6 '-iF"!~weekly until hatching was completed and then monthly thereafter. ~I.;.ii ".. ~ ",... ~'.'.',".'::,'i l"!il ['.-.•"." .-:>• .:. Because of their larger diameter the average number of chum eggs per tray (1.070)was less than the average number of sockeye eggs per tray (1,400).By the conclusion of the third egg collection,four incubators had three trays each of chum and three trays each of sockeye eggs representing the three egg takes (Table 1)and the four temperature "regimes.The four additional incuba- tors were used with an identical design to provide a complete replicate of the study. Table 1.Egg placement within a given incubator. (Each incubator and its replicate maintained a specific temperature regime.)u- _."l'i . I" Tray 1 2 3 4 5 6 7 8 Chum eggs Chum eggs Chum eggs Empty Sockeye eggs Sockeye eggs Sockeye eggs Empty Coll ected 09/03 Collected 09/09 Coll ected 09/15 Water to drain Coll ected 09/03 Collected 09/09 Coll ected 09/15 Water to drain -r L r'·''fJ ,~".... Two of the four water temperature regimes used in this study simulated natural temperatures in two reaches of the Upper Susitna River.The first regime simulated the record of a thermograph placed in the main-stem Susitna near Gold 'Creek at river mile 136.We designated this regime as "MS".The second regime simulated temperatures recorded by a thermograph within Slough 8A,a fl"known spawning area for chum and sockeye.We designated this regime as "52". L~ r t.i ,~ 7 r~· 1 Incubator water temperatures were adjusted up to twice weekly during the fall ...... and spring when the greatest river temperature fluctuations occurred.Person- nel from ADF&G~Su-Hydro Division~measured and informed NFRC personnel of all field water temperatures. .- .... - A third temperature regime (designated "51")was established as an intermedi- ary regime between M5 and 52.51 differed from 52 by 1°C.The fourth regime (designated 4°)was maintained at a constant 4°C for the duration of the study. Water from the main-stem 5usitna River overtopped Slough 8A during the winter of this study.The overtopping of,Slough 8A resulted in cold intragravel temperatures (near O°C)as determined by point measurements collected after i H the overtopping occurred.Because this condition did not represent typical -f"'-. ~'. t '-'1 \ i'• r-l - ~ l -L; '~['~ ...., I~i slough water temperature and due to the loss of the ADF&G continuous tempera- ture recorder~it was decided to use temperature data obtained from Slough 8A in 1981-1982 (Trihey 1982)as the new model for 52. Eggs were observed weekly during their early incubation and mortalities were removed from the egg rings.When eggs began to hatch~the alevins were re- moved from the egg rings daily and placed into additional plastic "al ev in rings"within the incubator tray.When 50 percent of the eggs had hatched within any given tray~30 alevins were removed~anesthetized and then weighed to the nearest 0.01 9 and measured (to 0.1 mm)for total length.After 95 percent of the eggs had hatched in any given tray~the styrofoam water block and rings were removed.Subsequently,a sample of 10 alevins was removed and anesthetized to obtain length measurements each week.Alevins removed from 8 incubator trays were not returned to the trays. Weekly samples continued until the alevins had completed yolk sac absorption. This stage was determined by observing the opening along the alevin's ventral surface which was separated by yolk sac.When the right and left ventral sides had sutured over the remnant yolk sac,the alevin was defined to have completed yolk absorption (CYA).When 50 percent CYA was achieved a sample of 30 alevins was removed and measured for total length • f'''Ito; L .- r'"'; IL;, r ( t ~ E ~i~i.i~ f'~ ~'" i'-" .- ,''''f::i ,~ f'~ i, ~ Data were compiled to provide comparisons for time to hatch and CYA in TUs and days.Mortalities and abnormalities for each temperature regime and egg co 11 ecti on were a1-so noted.The eggs withi n a few i ncuba tor trays ex peri enced , lethal stresses due to experimental errors and local power outages.Data from these trays were not used in analysis of length,weight and development rates but have been appended to this report (Appendix 1).For descriptive purposes, -data from replicates and the three egg-collection dates were often pooled.~ d~"When this was done,the raw data were entered into Appendix 1.° .-~" J :"~ ~ l " :"F L '.-f"", I,.---! A one way analysis of variance (Sakal and Rohlf 1969)for lengths and weights for each species at 50 percent hatch and complete yolk absorption was per- formed to compare all temperature regimes and egg-collection dates.If a significant difference was found (P<0.05)a Duncan multiple comparison test (Nie et aZ.1975)was performed to combine statistically similar groups (P=O.01)• Growth curves were constructed from weekly length measurements to evaluate 9 p.""r .>L"length as a function of temperature unit accumulation.Comparisons were also .~ made between development rates l (at various temperatures)for 5usitna River chum and sockeye and those of other chum and sockeye stocks reported in the .1j literature . .... Resul ts ..-r Water TemperatureI~ I]It was not possible to duplicate diurnal or within-week temperature variations taking place in the 5usitna River or Slough BA.However,a rough equivalence of temperature variation was produced during the salmon incubation period. The rapid temperature decline of the main-stem Susitna in the fall,its long winter period of O°C,and warming in the spring was simulated by the thermal (.'C Il.regime designated M5 in Fig.2.The coldest temperature we could maintain was 0.4 to 0.5°C because the water bath began to freeze if lower temperatures were .attempted.Because complete yolk absorption was achieved faster in 52 than in I 51,the 1°C temperature difference was maintained through late April only.We,..,-!.', i .... FI L I""\n U used intermittent reports from ADF&G to estimate subsequent temperatures for 51. The accumulated temperature units for all four temperature regimes and for the first and third egg collections (September 3 and 15)are presented in Figs.3 and 4.The major difference between the two egg-collection dates occurred within the main-stem temperature regime.Due to the declining water tempera- ture,eggs from the third collection that were incubated in the main-stem 1 Development rate is defined as the reciprocal of days from fertilization to a specific stage,such as complete yolk apsorption,multiplied by 1000 • ....~~-L......-. 10 MS '"'68 98 188 128 141 168 188 2B8 228 241 268 ~IU 388OCTt«lY DEC JAN FEB MAR APR MAY ,lUi' DAYS FROM FERTILIZATION ..... ;..,..~~~..-.......;.....~_/---4°..---------52 Temperature regimes for the Susitna River egg-incubation study which simulated the main-stem river (MS),Slough 8A (52),an intermediate regime (51),and 4°C Constant (4°).Regimes were plotted from 3 September 1982,the first egg collection period • 11 1 u 0 UJ 0:::::) ~< 0::: UJa.. :::E UJ ~ 0::: UJ ~<:-2 1 • "I 28 SEP Figure 2. .... .- ..!"""' - j{'. L F-f"C L w 959o U') ~-S 1.IJ 0::: ::) ~<0::: UJa.. ::::E UJ ~ C UJ ~<-J ::) :::E ::) U W-< SEP OCT NOY MS' 1..128 148 168 188 288 228 241 268 288 388 DEC "AN FEB MAR APR MAY "UN DAYS FROM FERTILIZATION ~.Figure 3.Accumulated temperature units at four different temperature re- gimes for the Susitna River egg-incubation study.Data were plot- ted from 3 September 1982,the first of three egg collection dates. The four regimes simulated the Susitna main stem (MS),Slough 8A (52),an intermediate regime (51),and 4°C Constant (4°). -I" II . \,:,,021) 11 Figure 4.Accumulated temperature units at four different temperature regimes for the Susitna River egg incubation study.Data were plotted from 15 September 1983,the third of three egg collection dates when chum and sockeye ova were fertilized.The four regimes simulated the Susitna main stem (MS),Slough 8A (52), an intermediate regime (51),and 4°C Constant (4°). r'I .iL r: ~o u 95B 0 U) I-..,... 768:z: :::::) lJJ 66Sa:: :::::) I-578-<a:: lJJ 475Q... ::::E lJJ l- e lJJ I--<...J :::::) ::::E :::::) U U-< .···51 )IS 48 68 88 188 128 148 ~6lI 188 2B8 228 248 26liJ 288 388 OCT NOV OEC JAN FEB MAR APR MAT JUN DAYS FROM FERTILIZATION I""'"f'" t'L~ .-r J .. j l-,,,,, thermal regime required 88 days to reach 200 TUs,while eggs from the first collection period required only 31 days to reach 200 TUs. Chum Salmon Five of the 24 incubator trays containing chum salmon were eliminated from analysis of growth and survival due to uncontrolled (lethal)stresses.These represented 52 (first and second egg collections)and the 4°C Constant repli- cate for all three egg collections.When 50 percent or more of the eggs remained viable,however,the subsequent data from those trays were included in the evaluations of time to hatch and complete yolk absorption . f 12 l:J ~t~,Incubation timing and survival: ~Computations of the average temperature (for each regime)to various develop- B mental stages allowed for standardized comparisons between temperature re- ~gimes.The average water temperature from egg fertilization to complete yolk absorption described a colder to warmer trend between the main stem,51,52 and 4°C Constant temperature regimes (Table 2). Table 2.Average water temperature during incubation of chum eggs and alevins to 50 percent hatch and complete yol k absorption in four temperature regimes.(Data were pooled from replicates and egg collections.) ~ .- E .~~ C Temperature regime Main stem 51 52 Constant 4°C Average water temperature (OC) 50 Percent hatch Complete yolk absorption 1.7 2.2 3.6 2.9 4.6 3.9 4.0 4.0 ~'f ~ I The number of days required from egg fertilization to 50 percent hatch and , complete yolk absorption (Appendix 1)is inversely proportional to increases in temperature between the four temperature regimes (Fig.5).Eggs required about 61 more days to reach 50 percent hatch and alevins required 70 more days to complete yolk absorption in the main-stem temperatures,as compared to the Constant 4°C or 52 temperatures. -[In contrast,the accumulation of TUs is directly proportional to the increases -fe:'in temperature between the four study regimes for egg hatching and compl ete .~ -~:~" .} !bi 13 rL yolk absorption (Fig.6).Eggs required about 187 fewer TUs to 50 percent hatch and alevins required 239 fewer TUs to complete yolk absorption in the main-stem temperatures as compared to the Constant 4°C or S2 temperatures (Appendix 1). 300 uChumSalmon°Chum Salmon iiic:+J 0 ''- .'-c: +J 250 :=:l rc:l N QJ 900 ''-~ ~:::::I .'-~800..j.J ~200 ~ u..~700 e e 0 ~600 ~ C+-"VI 150 ~SOD >,rc:l rc:l ';400Qe G 300100uc:r:MS SI S2 4°MS Sl S2 4° Temperature Regimes Temperature Regimes I \. -:n t F""'~., L r--, I "< ...., I . IL., -r ~ .Ii _ Figure 5.Days from fertilization to 50%hatch (cross- hatched bars)and complete yolk absorption (open bars) for chum salmon at four different temperature regimes which simulated the 5usitna main stem (MS), Slough 8A (52),an inter- mediary (51),and 4°C Constant (4°)•.(D~ta were pooled from three fertilization dates in September and from study replicates.) Figure 6.Accumulated temperature units (Oe)to reach 50% hatch (cross-hatched bars) and complete yolk absorp- tion (open bars)for chum salmon at four different tempe~ature regimes which simulated the Susitna main stem (M5),Slough SA (52), an intermediary (Sl),and 4°e Constant (4°).(Data were pooled from three fertilization dates in September and from study replicates.) - f"'=! l~.. ~~ .-. 'f'-A ~ ~ f ,.,..~ 1"t .:.... rL,~-r,'. t ';"~ r~.~-.~~ f""" rr~..I,J ~r.~ ..,.... 'c .. l :.- I"~t -Fe ,L~ [ .."""'(' .~ .-1'; i L 14 Thus,if chum salmon were spawning from early to mid-September in temperature regimes similar to those in this study,hatching would take place from mid- December to mid-March,and complete yolk absorption from early April to late June (Tabl e 3). Table 3.Dates for hatching and complete yolk absorption for chum eggs and alevins incubated in four temperature regimes based on spawning dates of September 3 and 15. Temperature Spawning 25 Percent 50 Percent 75 Percent Complete yolk regime date hatch hatch hatch absorption Main stem 03 Feb 06 Feb 11 Feb 16 Jun 16 Main stem 15 Mar 08 Mar 16 Mar 20 Jun 24 Sl 03 Dec 28 Dec "29 Jan 01 May 08 Sl 15 Jan 20 Jan 22 Jan 24 May 22 S2 03 Dec 15 Dec 17 Dec 18 Apr 06 S2 15 Dec 27 Dec 29 Dec 31 Apr 17 Constant 4°C 03 Dec 29 Dec 31 Jan 02 Apr 07 Constant 4°C 15 Jan 07 Jan 09 Jan 13 Apr 14 Chum egg and alevin survival was greater than 90 percent (Appendix 1)for all four temperature regimes (Fig.7).Abnormalities .noted in the main-stem temperature regime (0-2.2 percent)included curved spines,deformed body parts,and "head-first"hatching.The number of abnormalities noted in the other three temperature regimes was generally less than 0.1 percent in each incubator tray (Appendix 1). Lengths and weights: Weight measurements were taken through 50 percent hatch,and for selected alevins at complete yolk sac absorption.However,the weighing process was value between temperature regimes t 'so the measurements were discontinued.The time consuming and the results (from blot drying)had little interpretive Figure 7.Percent survival for chum salmon eggs and alevins reared to com- plete yolk absorption at four different temperature regimes which simulated the Susitna main stem (MS)t Slough 8A (S2)t an interme- diary (Sl)t and 4°C Constant (4°).Cross-hatched area represents percent of abnormalities among survivors.(Data were pooled from three fertilization dates in September and from study replicates.) 15 Chum Salmon 95 100 92 .5~~~~~~~MS Sl S2 4° Temperature Regimes 97.5 id Ii ..-r-o ~[ ~- r''''i L _'J.... r"'L,.... ij .....L n::J> ""'".... >['"~ ~ L ,:Vl +J "...c: ["CLlu L.:~ CLl Q. fP- r"IL·; .... mean weight for all chum alevins at 50 percent hatch was 0.20 g ±0.01 g (95 percent Cl).No weight analysis was performed between egg collections. -I I . l A one-way analysis of variance (ANOVA)for alevin lengths at 50 percent hatch for all temperature regimes and egg collections (minus the deleted trays mentioned earlier)revealed a statistically significant difference existed between the groups (P<O.Ol)(df=ll).With some exceptions,temperature regimes with colder average temperatures resulted in smaller alevin lengths at 50 percent hatch (Fig.8).A Duncan multiple comparison test (P=O.Ol)combined statistically similar groups which resulted in a separation of the warmest -I temperature regime from the coldest (Table 4).The difference in length from 16 -a; i.!~, i~the smaller to larger alevins was 2.5 mm (11 percent). r~"...;..,.,:.-,; ~~~ Table 4.Mean lengths of chum alevins at 50 percent hatch which are brack- eted into statistically similar groups (P=O.OI)and their corres- ponding temperature regime and egg collection.(Data were pooled within replicates.) t Mean 1ength (mm) 21.7 22.5 22.9 22.9 23.1 23 •I---1H-r 23.2 23.5 23 .7 --....,1--1 23.7-..-.J 24.1 24.2--..... 1.5 1.7 2.0 4.6 3.4 4.0 3.6 3.9 4.7 4.0 4.0 4.7 Chum Salmon Complete Yolk Absorption Average t t ( OC)empera ure 15 9 3 15 15 9 9 3 9 15 3 3 Egg collection date (September) > QJ t+++fO oO ++t t +rgoO +·~38.0 tt t+t <:22.0 +<: c c ~21.2 ·~37 .O~~~~~~~~~~ 123123123 123 123123123123 MS SI S2 4°MS SI S2 4° Temperature Regimes Temperature Regimes Mean lengths (horizontal lines)of chum salmon alevins at 50%hatch and at total yolk absorption from three fertili- zation dates (I=September 3;2=September 9;3=September 15) within each of four different temperature regimes.The temperature regimes simulated the Susitna main stem (MS), Slough 8A (S2),an intermediary (SI),and 4~C Constant (4°). (Data were pooled from study replicates.Vertical lines represent 95%confidence intervals.) c:..... 24.5 E 24.0 E- Figures 8 and 9. Temperature regime Main stem Main stem Main stem S2 SI Constant 4°C SI SI S2 Constant 4°C Constant 4°C S2 '-I~ L~ .~r.i··u i E ~i~ [f~-L~ ·~F f~, ib> 17 p ~::;~Length analysis (one-way ANOVA)of churn alevins at complete yolk absorption Growth and temperature unit accumulation: gimes and egg collections (P<O.Ol)(df=ll).Mean lengths and 95 percent confi- dence intervals of these groups are plotted in Fig.9.The difference in length between the smallest and largest group was 1.9 mm (5 percent). also revealed a significant difference between the groups of temperature re- Alevin growth (total length)was plotted versus accumulated temperature units (OC)for all four temperature regimes of the first egg collection (Figs.10 and 11)and for three temperature regimes of the third egg collection (Fig. 12).Comparative differences (TUs and days to 50 percent hatch and CYA) within a single egg collection were mentioned previously.Variations in growth curves (length vs TUs)are noted here.-A---greater deflection in the slope of the main-stern growth curves as compared to 51 and 52 was observed (Figs.10 and 12).The greatest change in slope for the main-stern growth curves appeared at about 380 TUs for the first egg collection and about 315 TUs for the third egg collection.For both egg collections in the main-stern temperature regime the decrease in slope in Figures 10 and 12 represented the effect of increased water temperature (greater than laC)which occurred during the first week in May.Thus~while development and growth were faster over ~i time (days)in the 4°C and 52 temperature regimes than the 51 or M5 regimes t", (Figs.5 and 10)~the alevin growth rate increased as a function of accumu- ....., 1 il~_,f"'" i -I ~U '~-"...;.•',y-:f ~':';; f0.-.'.•Ii ,..... E·· -·'······'···,.':~ :!,.~ "".'el"1·1 ~r: ~O .;-p l.:::lated temperature units when water temperature was less than laC (Figs.10 and -p..""..-.:..,l'b' ~r1' ,l,,~ 12). -f It........ 18 i'!r t; r~ I _ -:r; I.~,.: [~ 40 - .=. +oJ 0'1s::: ClJ -I 30 s::: .~ > ClJ.-c:x:: 20 Chum Salmon -Length Range -Mean 250 315 380 445 510 575 640 705 770 835 900 Accumulated Temperature Units (oC) Figure 10.Alevin growth (total length)from 50%hatch to complete yolk ab- sorption for chum salmon incubated at three different temperature regimes.The regimes simulated the Susitna main stem (MS),Slough 8A (52),and an interme~iary (51).(Data are based on a fertili- zation date of September 3.Data from replicates were pooled.) -lil>' 1 The constant 4°C water temperature regime is presented in a separate figure because of an almost complete overlap of data points with S2.Similarly,the growth curves for SI,S2 and Constant 4°C are almost identical when the first ,.....r 'L and third egg collections are compared.Differences between the main-stem ~a·~~"'t L _I j L growth curves for the first and third egg collections are due to the colder average water temperatures experienced by eggs from the third egg collection. ;,~ 19 45 40 Chum Salmon I II-I I.~~··~····i ~I ••~···(·I I I-35.s::: Constant 4.cl••·~··r I . ~ C'lc: QJ I • -l I J.··~·······Ic:30'...>QJ fltI'°*I....c:e l//[25 •.. I -Length Range,,,~ i 20 ,,,-t4ean I''"' L G ~r-id ~r lk '-F t Fi gure 11. I 445 536 627 718 809 900 Accumulated Temperature Units {oC} Alevin growth {total length}from 50%hatch to complete yolk absorption for chum salmon incubated at Constant 4°C.{Data are based on a fertilization date of September 3.} "... ··rr~ 'L; '~r~ L Development rates: Development rates were computed {to 50 percent hatch and complete yolk absorp- tion}and plotted from results of this study and available literature on chum incubation (Figs.13 and 14).A regression analysis was performed on the data for each incubation stage.In each regression r is equal to 0.99 (Table 5). Thus chum development rates are predictable for known temperature regimes. 20 i~ r-- I I 'c: ,.~ 40 -35~-s::. +-' g'30 11l -l c:::.... >11l:=:25 20 Chum Salmon ,,, ,,,, S2 -Length Range -t1ean r~,'.'IJ .-. -1, i ~t4,_ ~'. f -'! 250 315 380 445 510 575 640 705 770 835 900 Accumulated Temperature Units (oC) Figure 12.Alevin growth (total length)from 50%hatch to complete yolk ab- sorption for chum salmon incubated at three different temperature regimes.The regimes simulated the Susitna main stem (MS),Slough 8A (S2),and an intermediary (Sl).(Data are based on a fertili- zation date of September 15.Data from replicates were pooled.) ,... U1>-Chum-<c.......1 50%HatchlSI lSI "lSI--....,, UJ I-12 "-<a::: I-..:z UJ ,.."..~ 0-"C ......J ....UJ>4 *This ReportUJcoRaymond(1981 )~ ~#Bakkal a (1970):J:u 1111 3 6 9 12 AVG.INCUBATION TEMPERATURE(OC) ~-'Figure 13.Development rates to 50%hatch for chum salmon incubated at various temperatures (oC).The reciprocal of the days to 50% hatch was multiplied by 1000. I·' ~; 21 - Chum Complete Yolk Absorption + + ".a ..B *This Report l1J Raymond (1981) +Graybill et aZ.(l979) 3 6 9 AVG •INCUBATION TEMPERATURE(OC) BB~---------""'!:""""------~---------" 2 I· . '''..'.' .~ ',~ .~ Figure 14.Development rates to complete yolk absorption for chum salmon incubated at various temperatures (GC).The reciprocal of the days to complete yolk absorption was multiplied by 1000 . Table 5.Regression analysis of development rates at various average incubation temperatures for chum alevins to 50 percent hatch and complete yolk absorption from data in Figs.13 and 14. I""" I ! j -, i Y t- Incubation stage Analysis n Slope intercept r statistic 50 percent hatch y =mx +b 12 1.40 3.23 0.99 P<0.001 Complete yolk absorption y =mx +b 11 0.59 2.25 0.99 P<0.001 ,rr' 1-~ i-V 1 Soc keye Sa lmon -,f L -[ ,r-I~ .~I..!...;,t Six of the 24 incubator trays containing sockeye salmon were eliminated from analysis of growth and survival due to uncontrollable (lethal)stresses. These represented the thermal regimes from Sl (second egg collection),52 (second egg collection),S2 replicate (all three egg collections)and the :-1'Constant 4°C replicate (second egg collection).As with our analysis for chum 22 - salmon,when 50 percent or more of the eggs remained viable,the subsequent r'L- data from those trays were included in the evaluation of time to hatch and complete yolk absorption. Incubation timing and survival: Average temperature (for each regime)was calculated (Appendix 1)to make comparisons between temperature regimes and timing to 50 percent hatch and R[complete yolk absorptio'n (Table 6)• ..-r(,1 Table 6.Average water temperature during incubation of sockeye eggs and a1evins to 50 percent hatch and complete yolk absorption in four temperature regimes.(Data were pooled from replicates and egg collections.) Average water temperature (OC) 50 Percent hatch Complete yolk absor~tion -["~,"'" ') j ~ r:l,;LJ r 1 ~ f" L -'-" L Temperature regime Main stem Sl 52 Constant 4°C 1.5 3.3 4.2 4.0 2.1 3.0 3.9 4.0 ....f' <; L Sockeye eggs in the main-stem temperature regime required about 71 more days ~{to reach 50 percent hatch and a1evins required 56 more days to complete yo1 k L absorption as compared to the Constant 4°C or S2 temperatures (Fig.15). "'"'[" ,.t£ In comparison,eggs required about 291 fewer TUs (Appendix 1)to 50 percent hatch and alevins required 301 fewer TUs to complete yolk absorption in the main-stem temperatures than in the Constant 4°C or S2 temperatures (Fig.16). 23 Accumulated temperature units (OC)to reach 50% hatch (cross-hatched bars)and complete yolk absorption (open bars) for sQckeye salmon at four different tempera- ture regimes which simu- lated the Susitna main stem (MS),Slough 8A (S2),an intermediary (51),and 4°C Constant (4°).(Data were pooled from three fertilization dates in September and from study replicates.) Sockeye Salmon Figure 16. 950u 0"850 VI· +..> ~'c 750 +..>:::l ~eLl 650 ::l~ 3E 550 U/13 ~~450 0-s:~350 250 MS Sl S2 4° Temperature Regimes 285 Sockeye Salmon Days from fertilization to 50%hatch (cross- hatched bars)and com- plete yolk absorption (open bars)for sockeye salmon at four different temperature regimes which simulated the Susitna main stem (MS)~ Slough 8A (52),an intermediary (Sl),and 4°C Constant (4°). (Data were pooled from three fertilization dates in September and from study replicates.) VI>, ~125 M5 Sl S2 4° Temperature Regimes .-. 'r- +..> ~ eLl LI.. E 185o ~ l.f- s::o 'r- +..> /13 .~235 Figure 15. P'IS ,[".'.' >,,' '~ o rL, .- flI'!"IIL. f'"L f3:'.".'.'i\,Li :..... .PlIIlIi Therefore,if sockeye salmon were to spawn from early to mid-September in temperature regimes similar to those in this study,hatching would take place from late January to early May and complete yolk absorption would take place from mid April to late June (Table 7). ~r ~~ ~r~ :i l,; Sockeye egg and alevin survival was greater than 90 percent (Appendix 1)for all temperature regimes (Fig.17).Developmental abnormalities noted in incu- bator trays with main-stem and Constant 4°C temperatures (~0.3 percent) :-r' 't", 24 '- F"'" I If~tj -Table 7.Dates for hatching and complete yolk absorption for sockeye eggs and alevins incubated in four temperature regimes based on spawning dates of September 3 and 15. Temperature Spawni ng 25 Percent 50 Percent 75 Percent Complete yolk regime date hatch hatch hatch absorption Main stem 03 Mar 24 Mar 29 Apr as Jun 14 Main stem 15 May 01 May as May 10 Jun 25 SI 03 Feb 05 Feb 11 Feb 15 May 26 SI 15 Mar 01 Mar as Mar 09 Jun 09 S2 03 Jan 16 Jan 20 J'an 23 Apr 14 S2 15 Feb 04 Feb 10 Feb 12 May as Constant 4°C 03 Jan 28 Feb 01 Feb 04 Apr 12 Constant 4°C 15 Feb 11 Feb 14 Feb 17 Apr 26 95 IZ~I-e 100 .-- ~>0;97.5 ~ ::::len +Jc Ql U ~ Qlc.. Sockeye Salmon MS SI S2 4° Temperature Regimes Figure 17.Percent survival for sockeye salmon eggs and alevins reared to complete yolk absorption at four different temperature regimes which simulated the Susitna main stem (MS),Slough 8A (S2),an intermediary (SI),and 4°C Constant (4°).Cross-hatched area represents percent of abnormalities among survivors.(Data ~l were pooled from three fertilization dates in September and'L.from study replicates.) -\ L,,, ~,.I 6 included curved spines,twinning,double heads and tails,and head-first hatching (Appendix 1).Abnormalities in SI and S2 temperature regimes re- mained less than 0.1 percent in all incubator trays. -- 25 Lengths and weights: Analysis of sockeye weights at 50 percent hatch provided little interpretive r"~information.The mean weight of sockeye at 50 percent hatch was 0.11 g.Not; variation was observed between temperature regimes or egg collections when evaluated by a one-wayANOVA and a Duncan multiple comparison test (P=O.Ol) (df=10). F'«L. ['" I L· A one-way ANOVA for alevin lengths at 50 percent hatch for all temperature regimes and egg collections (minus the deleted trays mentioned earlier)re- vealed a statistically significant difference between the groups (P<O.Ol) (df=10).Similar to the chum lengths at 50 percent hatch~a trend was ob- served wherein colder average temperatures resulted in smaller alevin lengths (Fig.18).A Duncan multiple comparison test (P=O.Ol)combined statistically similar groups which resulted in the separation of the coldest and warmest l.temperature regimes (Table 8).The difference in length from the smaller to I l. !1I. la'rger alevins was 1.8 mm (8 percent). Length analysis (one-way ANOVA)of sockeye alevins at complete yolk absorption. also revealed a significant difference between the groups of temperature L regimes and egg collections (P<0.01)(df10).No trend was observed between r-[~mean lengths of alevins within the four regimes (Fig.19).The difference in length between the smallest and largest groups was 1.7 mm (5.7 percent).(If .11--those two groups were eliminated the range difference would be 0.6 mm.) II 26 Table 8.Mean lengths of sockeye alevins at 50 percent hatch which are bracketed into statistically similar groups (P=0.01)and their corresponding temperature regime and egg collection.(Data were pooled within replicates.) 24.0 32.0 tf +t ++ --eeee--t.c .c ~23.~31.0 s::++s:: ++t t t ++t ClJ t ClJ -l -l s::s:: .~.~ ~30.0 I.....+..... et:et:Sockeye Salmon 1-Sockeye Salmons::s::Complete Yolkn:J 50%Hatch n:J ClJ ClJ Absor tion~21.0 ::E:29 .0 1 23 123 123 123 1 23 123 123 1 2 3 MS S1 S2 4°~1S S1 S2 4° Temperature Regimes Temperature Regimes Egg collection date Average Mean Temperature regime (September)temperature (OC)length (mm) Main stem 09 1.5 21.8J Main stem 03 1.7 22.0 Main stem 15 1.3 22.5 S1 15 3.1 22.7 Constant 4°C 09 4.0 22.8 S1 09 3.3 22.9 S2 03 4.3 23.1 Constant 4°C 15 4.1 23.2 Constant 4°C 03 4.0 23.2 S1 03 3.4 23.3 S2 15 4.2 23.6 Figures 18 and 19.Mean lengths (horizontal lines)of sockeye salmon alevins at 50%hatch and at total yolk absorption from three fertilization dates (1 =September 3;2 =September 9; 3 =September 15)within each of four different tempera- ture regimes.The temperature regimes simulated the Susitna main stem (MS),Slough SA (S2),an intermediary (S1),and 4°C Constant (4°).(Data were pooled from study replicates.Vertical lines represent 95%confi- dence intervals.) ......·l·.··'·'. ;:..'~ .~ 27 Growth and temperature unit accumulation: Alevin growth (total length)was plotted versus accumulated temperature units-~(Oe)for all four temperature regimes of the first egg collection (Figs.20lJ ~~and 21)and for three temperature regimes of the third egg collection (Fig.rt,~ ,,- r:' L .-[:.'.~...';"".' -.;~ '" 22).The greatest change in growth-curve slope for the alevins of the first egg collection occurred in the main-stem temperature regime at about 380 TUs. This coincides with the increase in incubation temperature above 1°C . 3 Sockeye Salmon ..... ,r-r"-~, I ' t .... f< i 3 -E E .J:: oj-) C'l 25c: <IJ ....l c:..... > <IJ 2 ,,, ,,, -Length Range -Mean F""'i 1, ,,~ l \l L ..';" I I I I •I I 325 387.5 450512.5 575 637.5 700 762.5 825 887.5 950 Accumulated Temperature Units (oC) Figure 20.Alevin growth (total length)from 50%hatch to complete yolk ab- sorption for sockeye salmon incubated at three different tempera- ture regimes.Regimes simulated Susitna main stem (MS),Slough 8A (52)and an intermediary (51).(Data are based on a fertilization date of September 3.Data from replicates were pooled.) 28 -; 35 Sockeye Salmon Constant 4°C "... E t ~, ~:I:j; F.'..L ""'"B 30-EE.-.c -+.) C'l ~25 -I c .~ >OJ < 20 !It I 1111.)l······11 I II .1....·Ii rI I .I•••••••II [ !.l.»ji 1 Il~..f···i III q -Length Range ,, ;'"-Mean,,, 575 650 725 800 875 950 Accumulated Temperature Units (oC) ~ J ;ji i; Figure 21.Alevin growth (total length)from 50%hatch to complete yolk ab- sorption for sockeye salmon incubated at Constant 4°C.(Data are based on a fertilization date of September 3.) ,. ( ~.. \L; ..~T(•.·.L l' .~ The largest change in growth-curve slope for the alevins of the third egg collection occurred in the main-stem temperature regime at about 530 TUs. This coincides with an increase of water temperature above 10°C.The eggs of this regime (MS)had not reached 50 percent hatch until early May,when water temperatures were greater than lOC (Fig.22). The Constant 4°C water temperature regime is presented separately (Fig.21) -r because of an almost complete overlap of data points with S2.Similarly,the b 29 -Length Range I--I-+--I"M MS ~....I.....I,......S1 J.....).,J . ....., Il J){(I .'." .'[......j ........... .,.. Sockeye Salmon 30 -.r:.25 +-l C'l C ClJ ....J C .~ > ClJ <:20 - .-~ , "-Mean,,, 300 365 430 495 560 625 690 755 820 885 950 Accumulated Temperature Units (oC) Figure 22.Alevin growth (total length)from 50%hatch to complete yolk ab- sorption for sockeye salmon incubated at three different tempera- ture regimes.Regimess imulated--Susitna main stem (MS),Slough 8A (S2),and an intermediary (SI).(Data are based on a fertil iza- tion date of September 15.Data from replicates were pooled.) ~,. I t L - growth curves for SI,S2 and Constant 4°C are almost identical when the first and third egg collections are compared. Development rates: ~ l<~ ~r ~"" .......... :I.·.·.'.·~ Development rates were computed (to 50 percent hatch and complete yolk absorp- tion)and plotted for data from this study and from data available in the literature (Figs.23 and 24).A regression analysis was performed on the data for each incubation stage.The r value for each regression line was equal to -[.,'..•...;..0.99 (Table 9). ..F"'" E [J nU IT F,"!(j n,1tj Figure 23 . 30 2k1 ,...Sockeye U'l 50%Hatch>-160<+0....... lSI lSI lSI-12'""LlJ iiiI- 0<IIa:: 8 IlI-:z /1>.LlJ *This Report:::E •c-~Vel sen (1980)0 4 ... ....J • LlJ +Olsen (1968)> LlJ #revl eva (1951)0 Bil 3 6 9 12 AVG.INCUBATION TEMPERATURE coC) Development rates to 50%hatch for sockeye salmon incubated at various temperatures (OC).The reciprocal of the days to 50% hatch was multiplied by 1000. IlB!:------:-3------::-5-------::g:---------:?t2 ..... : ~[ i...r..).,~".. ,... U'l>-0<o....... lSI lSI lSI-'"" LlJ I- 0<a:: I-:z LlJ :::Ec-o ....J LlJ> LlJo 12 9 6 Sockeye Complete Yolk Absorption + +. + , + *This Report #01 sen (1968) +Do n9 (1981) ~r'~~: L. / Fi gure 24. AVG.INCUBATION TEMPERATURE coC) Development rates to complete yolk absorption for sockeye salmon incubated at various temperatures (Oe).The reciprocal of the days to complete yolk absorption was multiplied by 1000. - 31 Discussion tureranges. Thus,sockeye development rates are highly predictable within known tempera- t- statistic P<O.OOl P<O.OOI r 0.99 0.99 y intercept 3.71 2.61 Slope 0.15 0.14 n 11 13 Table 9.Regression analysis of developm~nt rates at various average in- cubation temperatures for sockeye alevins to 50 percent hatch and complete yolk absorption from data in Figs.23 and 24. Incubation stage Analysis 50 percent hatch lny =lnb +mx Complete yolk absorption lny =lnb +mx il".\:. .'W o Field observations indicate that chum and sockeye fry achieve complete yolk ,-absorption in Susitna sloughs by early April,and mid to late April,respec-r 1 tively (ADF&G 1983).These findings agree well with our results (Tables 3 and'-,~7)for the S2 (Slough 8A simulation)and Constallt 4°C temperature regimes. i .<-r' L F"'"!.'~ I t: Our study shows that Susitna River chum salmon achieve complete yolk sac absorption within 218 days of fertilization (Fig.5)when incubated at an average 3.9°C (see S2,Table 2)in a regime which simulated temperatures in Slough 8A.Incubation at a constant temperature of 4°C produced essentially the same result.Incubation at our two coldest regimes (SI and MS),however, lengthened ~he amount of time required for complete yolk absorption by about one and two months,respectively.These findings were similar for Susitna sockeye salmon which were incubated simultaneously within the same four temperature regimes (Fig.15 and Table 6). 32 ,~ It has been suggested that some salmonids can regulate development rates ,~(which determines incubation time)when subjected to altered temperature - regimes (Dong 1981).The ability of an egg or alevin to compensate their development rate for temperature changes could assist in achieving yolk absorption at the most optimal time for fry emergence.In thi s study the similarities in incubation time (TUs and days)between S2 and 4°C (constant) for chum and sockeye to reach complete yolk absorption is explalned by the similar average incubating temperature to yolk absorption within each regime and Sl)were also proportional to the decrease in the number of TUs accumu- ,.lated.Therefore~it is evident that chum and sockeye from Slough 11 "do not ""'"r, ,4c. have the ability to regulate their development rates to result in a similar number of days to complete yolk absorption when average incubation tempera- units (particularly below laC,see Figs.10 and 20). It is possible that the ,average post-project temperature regime will be out- _,side the range we evaluated in this study (2.1 to 4°C).As our data are directly applicable to a range at or below 4°C,it would be useful if a pre- - dictive model could estimate incubation timing for chum and sockeye beyond this range.This information is presented below.First however,we will suggest two possible temperature scenarios (which may result from reservoir construction)so that subsequent data presentations may be placed into per- [ '..~spective. ~~ l.·.;;.i ".": .~ },~r, b~J 33 First,a slight increase in the annual average water temperature of the 5usitna main stem may elevate winter ground-wate~temperatures in the sloughs. A warmer average,post-project temperature (for example,4.5°C)could result in an earlier fry emergence as compared to our warmest temperature regime (4°C constant). Conversely~fluctuations in winter discharge in the main stem could result in increased channel ice formation.Increased ice staging in the river may divert main stem flows and inundate sloughs with O°C water.This event occurred naturally in 510ugh 8A duri ng the winter of thi s study.If com- pletion of the incubation process were delayed by one to two months (as occurred in our main stem and 51 temperature simulations).smoltification of to the historical smolt timing because temperature has decreased or increased r'"rt;;,alevin development (Folmar et aZ.1982).The effect on sockeye salmon is less clear as this species will rear for another one to two years outside of the slough habitat before their outmigration as smolts. 1'" j1 ~, f .. ,[iI'll!lDIII; Our results with 5usitna River salmon indicate slight increases in mortalities and abnormalities begin when average incubation temperatures to hatch are less than 3.4°C for chum and sockeye.or when initial incubation temperatures are equal to 4°C for sockeye (Figs.7 and 17,Tables 4 and 8).Our coldest tem- perature regime was represented by the egg collection of 15 September incuba- ting in the main-stem simulation.Chum and sockeye eggs were incubating for 31 days with about 156 TUs (5°C average)before water temperatures were de-' rfa creased to 1.4°C in this regime.Sockeye eggs are noted for being vulnerable L. ~;-r; ; L r'" f \', i.) ,[~:; ,'""J.-,\·1 [.. -.'~.:.•...':' r···,,' LJ E'·~···;l ""_:~1 ~:~>-i: ·r."'"·,·'···. .,.." .;.. [ nu 34 to temperature stress before closure of the blastopore,which occurs at about 28 days and 140 TUs (5°C average)(Velsen 1980;Barns 1967;Combs 1965).Thus, our coldest temperature regime did not subject the eggs to thermal stresses before they could successfully adjust. Bailey and Evans (1971)reported an increase in mortalities for pink salmon (0.gorbusaha)when initial incubation was below 4.S o C,and complete,mortality occurred when initial incubation was below 2.0°C.Studies with coho salmon (0.kisutah)have also noted 100 percent mortality when eggs were initial,ly incubated in temperatures below I.O°C (Dong 1981). This type of cold-water stress (early in the incubation process)does not appear to be a likely post-project event in the Susitna.The inundation of sloughs later in the winter however,could quickly reduce incubating tempera- tures by 2 to 3°C.While this would definitely alter the timing of develop- , t ment processes,it appears that salmonid eggs are riot lethally stressed by-~such water-temperature changes when they are past closure of their blasto- pores. The mean length of chum and sockeye alevins was significantly smaller at hatching when incubated in colder average temperature regimes (MS and Sl vs S2 and 4°C)(Tables 4 and 8).These results have also been noted for variations r-f');L. rF L ....r c Il....... of other environmental conditions such as volume of eggs per incubator,dis- solved oxygen levels,substrate type and water flow (Kapuscinski and Lannan 1983;Fuss and Johnson 1982;Peterson et al.1977;Garside 1959;Hayes et al. 1953).Hatching can be advanced or delayed depending upon incubating condi- tions (Garside 1959),and Hayes et al.(1953)suggested cold water tempera- -.,~.,--'.-:. r'l'tL I'""" 35 If'"L tures would be expected to promote early hatching (relative to alevin length hatching,but rather,the alevins in colder water temperatures had hatched earlier relative to length development.Dong (1981)also concluded that the we dtd not observe a less efficient development process in cold water at development).In addition,the mean alevin lengths at complete yolk absorp- tion for chum and sockeye (Figs.9 and 19)did not reveal the corresponding differences between temperature regimes found at 50 percent hatch.Therefore, metabolic efficiency in coho alevins was comparable or higher at 1.3°C as [;opposed to 4.0 or 6.1°C.Temperatures higher than 6.1°C resulted in smaller Ft}'o·t,.... r"I- f""'" [" i.... ( ( I,..... ~, [' ['"I ," -,je, o f?' I l~l~~ alevin lengths at complete yolk absorption (Dong 1981). While the metabolic efficiency appears to be similar in our study tempera- tures,the growth rate did not.A clear increase in growth rates (as a function of days)resulted from increasing water temperatures above 1.0°C in the main-stem temperature regimes for both species (Figs.10,12,and 20;note April 15 in Figs.10 and 20).The increased growth rate with increased tem- perature overshadows the compensation that takes place with growth rates as a :l ~function of accumulated temperature units.i .. .... I !l, j L -r l __~ -[ 1'"""[ rr't A literature review and results from this study have produced a useful predic- tive tool for estimating the number of days needed from fertilization to hatching or complete yolk absorption for chum and sockeye salmon in the Susitna River System.Development rates have been calculated for both species given several average incubation temperatures and the information in Tables 5 and 9.The development rates were then converted to produce estimates of days to 50 percent hatch and complete yolk absorption (Table 10). rL:- - i.[j .k I {. -1······I.• -1 I I ~_< ~..--, 36 Table 10.Estimates of days to 50 percent hatch and complete yolk absorption (CYA)for Susitna River chum and sockeye salmon for a range of average incubating temperatures. Average Incubating Chum Sockeye Temperature (OC)50 percent hatch CYA 50 percent hatch CYA-- 1.5 188 319 217 313 2.0 166 292 200 292 2.5 149 269 186 272 3.0 135 249 172 254 3.5 123 232 160 238 4.0 113 217 148 222 4.5 105 204 138 207 5.0 98 193 128 193 Most water temperature scenarios that could occur downstream of operational dams on the Susitna River should be addressed by the range of average incuba- ting temperatures in Table 10.If,for example,a model of post-project water temperature predi cts that a slough (with incubati ng salmon eggs)will have an average temperature of 4.5°C from September to May,the number of days re- quired for chum and sockeye to reach complete yolk absorption would be esti- mated at 204 and 207 days (Table 10),respectively.This is 13 days earlier for chum and 15 days earlier for sockeye as compared to an average 4°C incu- bating regime (Table 10).Acceleration of the incubation process by 15 days would not be considered deleterious to chum and sockeye populations spawning within Susitna River sloughs.Those populations are spawning naturally for over a 30-day period with a large percent of the population in good spawning condition for over 15 days (ADF&G 1983).Conversely,ice processing may re- direct main-stem flows which could inundate sloughs and reduce average incu- bating temperatures to 2.0°C (as an example).If this were to occur,complete yolk absorption would be delayed about 75 days for chum alevins and 70 days for sockeye alevins as compared to an average 4°C temperature regime (Table 10). G 37 t"l~It is reasonable to assume that delaying the incubation process beyond 15 to .~. c ~ f)L1 ~nu D 20 days will begin to adversely affect the chum populatio~within the Susitna River sloughs.One hypothesis suggests that adult salmon run timing and sub- sequently their spawning time is genetically controlled (Ricker 1972)and adapted to historical water temperatures in their specific drainage (Miller and Brannon 1981).This hypothesis also identifies the selection pressure for a specific spawning period as the optimum time for fry emergence for each species.If the timing of chum fry emergence is altered beyond the range of historical emergence dates,and the run timing is genetically controlled,it would seem the population may not be able to rapidly compensate for any re- sulting poor survival of smolt.As mentioned previously,the timing of the parr-smolt transformation is known to playa role in the successful ocean survival of salmon smolt.It may be possible to indirectly quantify chum smO-lt-survival as it is affected by various-emergence times via salt water ~challenge tests.This stress test is referenced as an indicator of smolt r~ I L viability (Wedemeyer and McLeay 1981). An adverse effect on sockeye fry survival would also be anticipated i~the '~l·:' I:preceeding hypothesis is correct.However,quantification of survival for L, -r ~t . ,r[ "'-[.'~",,'. ,.'"d rr~ ,i"l~ sockeye fry from Susitna sloughs would be difficult as they generally move out of the sloughs after emergence and rear for one to two years throughout the Susitna drainage prior to outmigrating as parr/smolt (ADF&G 1983). Altering the thermal regimes and discharges of a major river may have many effects beyond those observed on salmon eggs and alevins.The results from this study indicate incubation timing is a factor which will be affected i~rG depending on the degree of water temperature alteration.All salmon fresh l.; .-r-~ il .. - 38 water life stages will be affected by changes in temperature regimes which act in concert with other factors as physiological regulators (metabolism and growth)and behavioral stimuli (migration and overwintering strategies).To the extent that post-project temperature regimes can be predicted,resource planners should be able to use data from this report to determine if incuba- tion timing will be affected and to attain management,mitigation or enhance~ r ment objectives. i;;; Acknowledgements Dana Schmidt (ADF&G)suggested the need for this study and,assisted in project design and review.Richard Fleming (APA)and Wayne Dyok (formerly ACRES)were instrumental in successfully contracting this project to NFRC.Special thanks are extended to.John McDonnell who helped construct and implement the incuba- tion facilities.His many late nights and weekends at the lab ensured the ~ I successful completion of this work.Keith Bayha and his staff (Ecological I.i, Services Division,USFWS)ensured the timely commencement of administrative contracting. trip to Slough 11. 39 - r"'l Several (USFWS)people also provided support.Among those we thank Martha Ronaldson (typing),Tim Whitley (technician),Brad Grein (graphics)and Jo Gorder (contracting).We appreciate the assistance of NMFS employees such as Sid Korn,Adam Moles and Stanley Rice,all of whom provided helpful advice. - rI., I[ B- Literature Cited Alaska Department of Fish and Game.1983.Susitna Hydro Aquatic Studies Phase II Final Data Report Vol.2 and 3,1982. Alderdice,D.F.and F.P.J.Velsen.1978.Relation between temperature and incubation time for eggs of chinook salmon (Oncorhynchus tshawytscha).J. Fish.Res.Board Can.35:69-75. r~ 1i Bailey,J.E.and D.R.Evans.1971.The low-temperature threshold for pink -salmon eggs in relation to a proposed hydroelectric installation.Fish. Bull.Vol.69(3). Bakkala,R.G.1970.Synopsis of biological data on the chum salmon,Oncor- hynchus keta (Walbaum).FAO Fisheries Synopsis No.41.U.S.Fish Wild. f't Servo Circ.315.t~ r-r"Barns,R.A.1967.A review of the literature on the effects of changes in L" rT·· i L--" temperature regime or developing sockeye salmon eggs and alevins.J. Fish.Res.Board Can.,MS,949:14-22. .-:..•.:.'--~ 40 .~ [}Baxter,R.M.and P.Glaude.1980.Environmental effects of dams and impound- ments in Canada:experience and prospects.Can.Bull.Fish.Aquat.Sci. 205:34 p. Combs,B.D.1965.Effect of temperaturezon the development of salmon eggs . Prog.Fish.Cult.27(3). """" Dong,J.N.1981.Thermal tolerance and rate of development of coho salmon embryos.M.S.thesis,Univ.Washington. Folmar,L.C.,W.W.Oickhoff,C.V.W.Mahnken,and F.W.Waknitz.1982.Stunt- ing and parr-reversion during smoltification of coho salmon (Oncorhynchus kisutch).Aquaculture 28:91-104. ~Fuss,H.J.and C.Johnson.1982.Quality of chum salmon fry improved byp lZ incubation over artificial substrates.Prog.Fish.Cult.(44)4. Garside,E.T.1959.Some effects of oxygen in relation to temperature on the development of lake trout embryos.Can.J.Zool.Vol.37. '-I. L~ rr~ !i'L Graybill,J.P.,R.L.Burgner,J.C.Gislason,P.E.Huffman,K.H.Wyman,R.G. Gibbons,K.W.Kruko,Q.J.Stober,T.W.Fagnan,A.P.Stayman,and O.M. Eggers.1979.Assessment of the reservoir-related effects of the Skagit project on downstream fishery resources of the Skagit River,Washington. FRI-VW-7905.Univ.of Washington,Seattle. Hayes,F.R.,O.Pelluet,and E.Gorham.1953.Some effects of temperature on r'rt..: '- 41 the embryonic development of the salmon (SaZmo saZar).Can.J.of Zool. Vo 1.31. ,.... c [1 r- ["" ·i-0;....~ .,.,ji r-r 1 . (.:-,F' 1-,,~ "'J'i '~r-"-,,I i .l.~ :-1 ., "L~ Ievleva,M.Ya.1951.Morphology and rate of embryonic development of Pacific salmon.Jzvestiya Tikhookeanskogo nauchno Vol.34,pp.123-130 •. Kapuscinski,A.R.D.,and J.E.Lannan.1983.'On density of chum salmon (Oncorhynchus ketal eggs in shallow matrix substrate incubators.Can.J. Fish.Aquat.Sci.40:185-191. Leitritz,E.and R.C.lewis.1980.Trout and salmon culture (hatchery methods).Calif.Fish Bull.No.164.University of California,Berkeley. Miller,R.J.and E.l.Brannon.1981.The origin and development of life history patterns in Pacific salmonids,p.296-309.In:E.l.Brannon and E.O.Salo,editors,Proceedings of the salmon and trout migratory behavior symposium.School of Fisheries,Univ.Wash.,Seattle,Washington. Nie,N.H.,C.H.Hull,J.G.Jenkins,K.Steinbrenner and D.H.Bert.1975. Statistical package for the social sciences.McGraw-Hill Book Co. Olsen,J.C.1968.Physical environment and egg development in a mainland beach area and an island beach area of Iliamna lake.In:Further Studies of Alaska Sockeye Salmon.Univ.Wash.Pub.in Fisheries.New Series Vol. III,Robert l.Burgner Ced.). r'[J Peterson,R.H.,H.C.E.Spinney,and A.Sreedharan.1977.Development of ;.';-",-,-""..-,,-,-,':.... rto<, r---, I I '. l If•.'."it' il" [......•..(" :il E n E ..... 42 Atlantic salmon (SaZmo saZaP)eggs and alevins under varied temperature regimes.J.Fish.Res.Board Can.34:31-43. Raymond,J .A.1981.Incubation of fall chum salmon (Oncorhynchus keta)at Clear Air Force Station,Alaska.Alaska Dept.of Fish and Game Info. Leaflet No.189. Ricker,W.E.1972.Hereditary and environmental factors affecting certain salmonid populations,p.19-160.In:R.C.Simon and P.A.Larkin,editors, The stock concept in Pacific salmon.H.R.Mac Millan Lectures in Fish- eries.Univ.of British Columbia,Vancouver. Sokal,R.R.and F.S.Rohlf.1969.Biometry.State Univ.of New York at Stony Brook.W.H.Freeman and Co.;San--Francisco.------ Trihey,E.W.1982.1982 Winter temperature study.Acres American Inc. Buffalo,New York • r:'i.Vel sen,F.P.J.1980.Embryonic development in eggs of sockeye salmon (Oncor- ir' I "l:,', hynchus nerka).Canadian Special Publication of Fisheries and Aquatic Sciences 49. Wedemeyer,G.A.and D.J.McLeay.1981.Methods for determining the tolerance of fishes to environmental stressors.In:A.D.Pickering,editor,Stress and Fish.Academic Press. '~~~J r-~=1 I;.j r=~] r~...",..):~__'Jl "') G,--::J ~l k,..•1 ~!.J- '~1 )i"ilL'~'~~',J.~,~» k,':',.j t<·;,.',j b,·,·",.d ~--,1 .l " 1 ._..'J 'j 1 .1 1 Appendix 1.Experimental design and associated data for chum (trays 1-3)and sockeye (trays 5-7)salmon to achieve 50%hatch and complete yolk absorption at four different temperature regimes.Regimes (each was replicated)simulated the main-stem Susitna River,Slough 8A (52),an intermediary regime (51),and a Constant 4°C. (Eggs for this study were fertilized on three occasions during September,1982.) i Incubator Main 5tem SI S2 Cons tant 4·C -- Tray 1 2 3 5 6 7 1 2 3 5 6 7 1 2 3 5 6 7 1 2 3 5 6 7 .<:TU'sl 320 293 262 349 321 299 457 446 444 552 558 535 491 508 478 606 607 613 476 473 471 610 618 595 ~u 0 ....- Ul ~Days since 161 172 182 211 217 235 lIT 122 131 161 173 172 105 112 106 140 142 147 119 117 116 152 152 146fertilization .>.<TU's1 614 635 638 594 583 616 733 746 721 793 818 810 860 -842 883 -895 865 863 871 889 875 909 .-c:•g,.~Days Slnce 287 286 284 285 281 282 246 253 250 264 269 268 218 -216 225 -232 216 213 214 222 216 223~~fertilization +'s..Percent 94 91 92 95 98 97 96 98 97 98 99 97 99 99 97 98 98 97 98 97~° .1 ----'O-J::surVlva _.-----~--.._--._.--,-'.._--'---I-- ~r<I Percent D 0.9 1.8 <0.1 0.1 0.1 0 0 0.2 0 -<0.1 --0.1 ,0 -0 0 0.1 0 0 o 0.3 u ~hnn ..m"1 i Hoc Incubator Hain Stem Replicate 51 Replicate 52 Replicate Constant 4°C Replicate Tray 1 2 3 5 6 7 1 2 3 5 6 7 1 2 3 5 6 7 1 2 3 5 6 7 .<:TU's1 320 292 266 344 320 294 457 444 435 546 534 521 493 486 478 620 616 622 -473 472 602 605 607"",U o+'---...,jg Days since 162 173 182 204 215 230 118 122 128 161 164 168 105 104 105 145 147 149 -117 117 151 150 150fertl1ization .>.<TU'sl 594 604 606 584 584 648 731 730 708 791 772 792 849 854 834 876 938 919 -856 843 889 906 910 .-C:_..._-.- g,00ays since 285 283 281 284 281 285 249 252 249 266 262 266 213 216 213 222 241 238 212 208 223 224 224'::;fertll ization - ~c::l--=----.--,.-...._..-'----_.-----------.~-~~---~--~'--- +'s..Percent 96 95 94 96 98 98!!!.g survival 98 98 99 98 99 98 97 96 93 -I -----98 92 98 1;1..0 .-~._.-------'1---------_____0 _._.-..---'-'--_..._-_..------.3 r<I Percent .0.3 1.5 2.2 0.2 0 0 0 0 0 0 -0.1 0 °0 0 - - 0 0 0.1 1 TU's _accumulated temperature units (OC). -Dashes indicate that data were lost due to uncontrolled stresses. ...".,w