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HomeMy WebLinkAboutAPA346Q Q FRESHWATER HABITAT RELATIONSHIPS DOLLY VARDEN-SALVELINUS MALMA (WALBAUM) ALASKA DEPARTMENT OF FISH & GAME HABITAT PROTECTION SECTION RESOURCE ASSESSMENT BRANCH JULY, 1982 FRESHWATER HABITAT RELATIONSHIPS DOLLY VARDEN CHAR (SALVELINUS HALMA (WALBAUM )) By e Steven W. Kru~er Alaska Department of Fish and Game Habitat Division Resource Assessment Branch 570 West 53rd Street Anchorage, Alaska 99502 May 1981 Acknowledgements Fisheries biologists from the Alaska Department of Fish and Game,the U.S. Forest Service.U.S.Fish and Wildlife Service,National Marine Fisheries Service-Auke Bay Laboratory.Bureau of Land Management,and the Arctic Environmental Information and Data Center provided insight into this project and deserve recognition.The assistance of librarians at the Alaska Resource Library,the U.S.Fish and Wildlife Service Library-Anchorage and the Commercial Fisheries Library-Alaska Department of Fish and Game-Juneau is heartily appreciated. This project was funded by the U.S.Fish and Wildlife Service.Western Energy and Land Use Team.Habitat Evaluation Procedure Group.Fort Collins. Colorado.Contract No.14-16-0009-79-119. • I TABLE OF CONTENTS •Page I.Introduction 1•A.Purpose 1 B.Distribution 2•C.Life History Sumnary 2 D.Economic Importance 14 II.Specific Habitat Requirements 15•A.Upstream Migration 15 I.Stream Flow 15•2.Water Temperature 15 3.light 16 4.Current Velocity 16•B.Spawning 16 l.Current Velocity 16 2.Substrate 16•3.Watpr Depth 17 4.Cover 17 •C.Inmigrant Migration to Overwintering Areas 17 •D.Inmigrant Overwintering Areas 18 E.Egg and Alevin Development 18 l.Water Temperature 18•F.Summer Juvenile Rearing 18 l.Water Depth 18•2.Current Velocity 18 3.Instream Cover 19 4.Substrate 19•G.Juvenile Migration to Overwintering Areas 20 l.Water Temperature 20•2.Stream Flow 20 H.Juvenile Overwintering'Areas 20•l.Water Temperature 20 2.Streanr Flow 21 3.Substrate 21• • • Page I.Juvenile Migration to Summer Rearing Areas 22 I.Water Temperature 22 2.Stream Flow 22 J.Inmigrant Migration to Sea 22 I.Water Temperature 22 2.Stream Flow 22 3.Light 23 K.Smalt Migration to Sea 23 I.Water Temperatures 23 2.Stream Flow 24 3.Light 24 II I.Conceptual Suitability Index Curves 25 IV.Deficiencies in Data Base 26 V.Recommendations and Further Studies 29 VI.Literature Cited 33 I I I I I I I I I I I I I I I I I I I I.INTROOUCTION A.Purpose The purpose of this project is to describe how selected physical and chemical features of lotic habitat within Alaska influence the survival and behavior of the various life stages of anadromaus 0011y Varden char (Sal.elinus malma (Walbaum». Objectives of this project are: 1.to gather data from published and unpublished sources within Alaska and from conversations with Alaskan fishery biologists concerning the relationships between lotic aquatic habitat.and anadromou5 Dolly Varden survival and behavi or. 2.to develop an Alaska data base for habitat-anadromoU5 Dolly Varden char relationships.Because there are not sufficient data for the relationships between anadromou5 Dolly Varden char and conditions of the habitat,habitat suitabil ity index relationships were not developed. 3.to identify data gaps and recommend appropriate projects to alleviate these gaps. The following Life History Summary and Specific Habitat Relationships/Requirements sections will identify the lotic habitat relationships of the various life history and seasonal behavior stages of the anadromous Dolly Varden char which include: upstream soawning migration, spawning, inmigrant migratio~to overwintering areas, -1- inmi grant overwi nteri ng areas, egg and alevin development, summer juvenile rearing, juvenile migration to overwintering areas, juvenile overwintering areas, juvenile migration to summer rearing areas, inmigrant migration to sea,and smelt migration to sea B.Distribution The taxon~of the Dolly Varden char,Sa1velinus malma (Wa1baum) is quite complex and a topic of debate.Morrow (1980)recognizes a northern and a southern form of Dolly Varden char,with the northern form equivalent to the anadromous Arctic char, Sa 1ve li nus a1pi nus (L i nnaeus),and the southern form compri sing the Dolly Varden char.Dolly Varden char is separate from the bull char.Salvel;nus confluentus,which occurs in British Columbia.Washington.Oregon.Idaho and Hontana (Behnke;1980). For purposes of this paper,Dolly Yarden char are defined as those fish which occur south of the Arctic char and north of the bull char.Anadromous and non~anadromous Dolly Varden char are distributed within Alaska south of the Alaska Range. C.Life HistOry S.......ry Migration of eature and i ...ture 0011y Varden char from the ocean to southeastern Alaska .ay be concurrent and can extend from July through October.I_ture individuals may stay in streams as long as spawners (two to three months)a1 though non-spawni ng 1rrmature Dolly Varden char seldom remain more than one month' prior to emigrating to other stream and lake systems,probably to overwi nter.About 80S of the non-spawn;ng inn1 grants 1eft Hood Bay Creek,Alaska before the spawning fish (Armstrong and -2- I I I I I I I I I I I I I I I I I I I Winslow,1968).Dur~ng 1966,tagged inmature fish remained in Hood Bay Creek for 14 days (Armstrong.1967).and mature fi sh for 85 days. Age at maturity is variable,most Dolly Varden in southeast Alaska reach maturity by age fOtU'or five.Hales may mature before females (Armstrong and Blackett,1965). Tagging studies in southeast Alaska (Annstrong,1965a and 1974; Blackett,1968.Heiser,1966)indicated that mature.anadromou5 Dolly Varden char use their natal streams to spawn and lakes to overwinter.Inmature f1sh or1 gi nati n9 '{n streams without lakes may enter several streams prior to finding a lake for ~ve".,intering.Innature fish of lake-stream origin probably re-enter the same system to overw1 nter.These taggi ng stud;es indicate that inmature and spawned-out anadromous Dolly Varden char from numerous stream systems may use the same lake for ovent1ntering. The Dolly Varden,like other chars,usually spawns between September and NoveniJer (Scott and Crossman,1973).B1 ackett (1968)determined that the peak of spawning activity in Hood Bay Creek occurred be~~een late October and early November.Spawning occurs in other southeastern Alaska streams from mid-September to mid-October (Blackett,1968;Blackett and Annstrong,1965).Both sexes display spawning coloration,although males are often scarlet on the ventral side and have black snouts. Selection of spawning sites by anadromaus Dolly Varden char appears to be influenced by various physical factors including curre;tt ve 1oei ty,water depth and substrate compositi on.Fi sh have been reported spawning in sidechannel and mainstem riffle/run and pool reaches of streams on Kodiak Island and in southeast Alaska (Blackett,1968;Wilson,Trihey,Baldrige, Evans,Thiele and Trudgen.1981). -3- Limited observations indicate that ...,.~fish's spawning behavior is similar to other chars (Blackett,1968;Scott and Crossman, 1973).Fish are usually paired.although more than one male may accompany a female (the largest male is usually dominant).The female is solely responsible for excavation of the redd (a depression in the stream substrate where fish spawn and deposit fertilized eggs).She forms the redd by turning on her side and thrashing the substrate with her caudal fin.The completed redd is typically oblong shaped.Dimensions of the redd .ary with the size of the female and substrate and current velocities;redds are generally 30 to 61 em (12-24 in)long and may be as deep as 30 em (12 in).The male spawner acti.ely defends the redd from male intruders and will nip and bite other males,sometimes grasping another male in the caudal peduncle for up to six seconds.Female spawners are not aggressive.(Blackett,196B) Fecundity of Dolly Varden char is variable among anadromous Alaska stocks ~nd is greater with increasing female fish age and length (Blackett,1968).For exa""1e,fema 1es about 300 mm f1 (fork length)from Hood 8ay Creek,Alaska contained less than 1000 eggs and females exceeding 450 mm f1 supported at least 2000 eggs.Ripe eggs are usually 0.45 to 0.6 em in diameter (Blackett,1968). The spawning pair descend into the redd and press against each other laterally.After the pair completes spawning the female may dig at the upstream end of the redd and displace gravel over the ferti1 ized eggs.This gra.e1 layer probably protects the eggs from sunlight and predation,reduces mechanical disturbance by ice and other objects while allowing water to transport oxygen to and metabolic wastes from the developing eggs. Fish may spawn again with the same or a different partner and. unlike salmon,are capable in subsequent years.Males are less likely to survive spawning than females (Annstrong and Kissner, I I I I I I I I I I I I I I I I I I I 1969).Armstrong and Kissner (1969)estimated that post-spawning mortality in Hood Bay Creek,Alaska was about 61%for male fish and 4:for female fish in 1967 and about 49%for male fish and 9% for fema 1e f;sh in 1968.Th i 5 di fferent;a1 morta 1i ty 15 not understood"but the aggressive behavior of male spawners is pr~bab'y a factor. Emigration of spawned-out Dolly Varden char to the sea or to overwintering areas usually occurs w1thin two weeks after completion of spawning.Fish surveys in Hood Bay Creek indicated that all spawned-out adults left the stream by late November (Armstrong and Winslow,1968).These fish may have entered the ocean to feed for several months or moved to overwintering areas (Armstrong,1974). longevity of Dolly Varden char is variable but fish in southeast Alaska may live nine to twelve years (Heiser,1966;Annstrong. 1963). Development of Dolly Varden eggs and alevins to the emergent fry stage requires about 210 days (Blackett,1968).Hatching has been documented from 129 to 136 days at 8.S·C.The 1.5 to 2.0 em long alevin typically remains in the gravel for an additional 60 to 70 days. Limfted research has focused on the survival of anadromous Dolly Varden eggs and ale.ins.Blackett (1968)est1mated that egg to alevfn survival ~fthfn an area of Hood Bay Creek,Alaska was about 41 percent. Intrag ..vel flow,dissolved oxygen and sed1ment cOll1llosition can influence the development and sUl"'YiYal of salmonfd eggs and· alevins.Little work has focused on egg and alevfn survival in relation to physical and chemical factors.Inferences can be made from work on other salmonid species.For example,transport -5- of dissolved oxygen to and metabolic wastes from developing eggs and a1evi ns by i ntragrave 1 flow is cruci a1 for surv;va 1 of salmonid eggs and alevins (Vaux,1962;Wickett,1958). Relatively low intragravel dissolved oxygen levels during the egg development stage of various salmonids may increase egg mortality,delay or hasten egg development or reduce the fitness of alevins (Alderdice,Wickett and Brett,1958;Silver,Warren and Quodoroff,1963).Coble (1961)and other investigators have determined that salmonid egg survival 15 enhanced by increased intragravel flow despite sufficient intragravel dissolved oxygen levels.Factors wh"ich could reduce the quantity or quality of intragravel water include reduced streamflow,sedimentation,and acculrlJlation of organic debris (McNeil and Ahnell,1964;Koski, 1966;Reiser and Bjornn,1979). Severt streamflow alterations can ham developing salmonid eggs and embryos.Mechanical scouring of the redd could dislodge substrate and destroy developing eggs and embryos.HeNei1 (1966) observed damaged pink and chum salmon redds and displaced eggs of both species in several southeastern Alaska streams following autumn spates.Koski (1966)reported low survival of coho salmon eggs subjected to freshets several days after 'Odd construction. Low flows and cold winter temperatures could cause redds to desiccate or to freeze.HeNei1 (1966)noted low survival of pink and chum salmon eggs in streams with low winter flows during harsh winter conditions in southeast Alaska. Koski (1966)determined that significant accumulations of fine sediments within chum salmon redds can retard or prevent the emergence of fry.Deposition of fine sediments in anadromous Dolly Varden char spawning areas could retard or prevent fry from . emerging. -6- I I, I I I I I I I I I I I I I I I I I I I I I I Water temperature affects hatching rates of salmcnid eggs;warmer than normal water temperatures can accelerate hatching and result in earlier than normal fry emergence (Sheridan,1962).Black.ett (1968)determined that Dolly Varden be9an hatching after 129 days in water with a mean temperature of 8.5°C.No upper or lower temperature tolerance limits of Dolly Varden char eggs or alevins were found in the literature. Upon emergence,anadromous Dolly Varden char occupy relatively quiet stream reaches.Blackett (1968)and Armstrong and Ell iot (1972)noted yoy fish in shallow stream margins of Hood Bay Creek,Alaska.Armstrong and Elli ott also found yoy fi sh in rivulets along Hood Bay Creek during early summer.These stream margins were efte"only 1 m wide and 4 em deep.No evidence of yay fish entrapment ~y dewatering within these stream margins was detected in the literature.Yoy Dolly Varden,which feed primarily from the benthos.characteristically remain on or near the substrate.sometimes remaining motionless and occupying gravel interstices.Yoy coho salmon.however.feed primarily from the surface within these same areas (Blackett,1968). Earlier research indicates that juvenile salmonids occupy areas (Wickham,1967)with relatively slow current velocities often adjacent to areas with faster current velocities and with higher densities of drifting invertebrates (Everest and Chapman,1972). A fish moves periodically into the areas of greater food availability to forage and returns to resting positions in areas of slower current.This minimizes energy expenditures and maximizes foeding success (Chapman and Bjomn,1969).As fi sh grow they a.=ten occupy deeper and faster areas of the stream (Everest and Chapman,1972).This behavi or probab ly app1;es to juvenile O<lly Varden char.Leggett (1969)suggested that the' cyl1ndricai body shape of bull char,which is IIIllrphologically similar to Dolly V.rden,probably enables these fish to occupy -7- areas of faster current velocities than most other salmonids. Other salmanids typically have laterally compressed bodies. Habitat selection by older pre-smalt Dolly Yarden char is not well documented 9 although the char are distributed in deeper. sometimes faster habitat than yay fish.Heiser (1966)noted that yearling and older pre-smalt Dolly Varden char occupied both still and flowi ng reaches of severa 1 in 1et tri butaries of Eva Lake.This lake was characterized by gravel and silt substrate! with varying amounts of vegetation.Researchers studying Hooc Bay Creek classified it into ten habitat types ranging frerl sloughs.undercut bank margins.pools and riffles.Baited minn~1 traps were placed in each habitat type 9 and length and frequenc' of pre-smalt coho salmon and Dolly Varden char were ;ompared fron each habitat type during July and August 1971.Pre-smolt Dolly Varden char and coho salmon were taken from all habitat types. The smallest Dolly Varden char (41-50 am)were taken in sloughs and sidechannel undercut bank a~as.and the largest Dolly VardE' were found in riffles. Yearling and older pre-smalt Dolly Varden char occupy "pools. quiet sidechannels and sloughs and tributaries off the mainstem! of both .••"the Terror and Kizhuyak Rivers.Alaska.althollgh juvenile fish are occasionally found behind boulders in faster water (Wilson.Trihey.Baldrige.Thiele and Trudgen.1981). Minnow traps were found to give a biased indication of habitat occupancy by fish because the bait may attract fish from a considerable distance.Habitat conditions where the fish are actually residing may be quite different from conditions immediately around the trap. Reed and Armstrong (1971)noted that juvenile coho salmon and Dolly Varden char were capable of entering and exiting baited mi nnow traps fi shed for 24 hours.The placement of two i engths -8- I I I I I I I I I I I I I I I I I I I of wire across the entrance to each trap resu'1ted in a higher fish retention rate. Distribution and abundance of pre-smalt Dolly Varden char may be i nfl uenced by ;ntra and i nterspec;fi c fi sh interact;ons. Observations of juvenile coho salmon,Oncorhynchus kisutch (Walbaum).and D~1iy Varden char in Hood Bay Creek.and in aquariums (Annstrong and Ell iott.1972)reveal ed that Dolly Varden fry are aggressive among themselves and in association with coho fry.Dolly Varden were frequently attacked by coho sa 1mon fry but were never observed attack i n9 coho fry.More Dolly Varden fry remained near the substrate when associated with coho fry than when they were alone.Coho fry occupied the upper half of the aquaria when alone and with Dolly V~rden char fry. Aquaria tests with older~pre-smolt Dolly Varden char and coho salmon indicated that Dolly Varden established and defended territories when a lone and when with 'coho fi ngerl ings.Do 11 y Varden fingerlings generally occupied positions within the aquaria at or near the bottom,but when alone,they occupied more mi d and sha 11 ow depth positi ons.Coho fi ngerl i ngs were consistently found in the upper strata of aquaria ard seldom attacked Dolly Varden char fingerlings (Annstrong and Elliott. 1972). Juvenile.anadromous Dolly Varden char grow relatively slowly during the three to four years prior to emigrating to the Pacific Ocean.Young of the year fish from Hood Bay Creek.Alaska grew about 10 rrm between July 7 and October I.1965.reachi ng a rr.ean fork length of about 38 rrm (Blackett,1968).Growth rates of pre-smelt fish may vary and length ranges of yoy and older age classes often overlap.Pre-smolt fish in Alaska generally grow· 10 to 30 mm annually.primarily during the summer months (Armstron9.1963;Heiser,1966;Blackett,1968). -9- The summer diet of stream rearing pre-smolt Dolly Varden char is influenced by food availabfl ity.fish size and stream habitat selection (Armstrong and Elliott.1972).Gut analysis of pre-smolt fish from Hood Bay Creek during the sumner rearing period (April to November)showed that substantial nuRbers of inrnature and adu1t aquatic insects were eaten throughout this period.8mergent and emigrant yoy salmon consumed invertebrates from April to June and sa lmon eggs from Ju ly to November. Relatively large pre-smalt Dolly Var'den char ate more and larger food iteDIs than smaller fish.Pre-smalt fish occupying stream reaches characterized b)overhanging vegetation and relatively low current velocities (such as sloughs and stream margins) generally consumed more terrestrial and surface floating insects than fish occupying mid-channel areas with moderate to fast current velocities and with greater invertebrate drift.ho drift samp 1es were taken to compare dri ft compos iti on with fi sh gut contents.Prl!-smalt Dolly Varden char occupy areas at or very near the substrate in streams with coho salmon.The char may browse along the substrate Or consume drifting invertebrates (Armstron9 and Elliott.1972). Land practices which result in removal of vegetation along stream margins and deposition of fine sediments in the stream channel cou 1d pass;bly reduce the abundance and fitness of pre-sma It Dolly Varden char (Armstron9 and Elliott.1972;Elliott and Dinneford.1976). The seasonal distribution of pre-smolt Dolly Varden char is apparently influenced by fluctuating flows and declining water temperatures during the late sumner and fall.Fish appeared to be distributed evenly throughout Hood Bay Creek.Alaska from Juiy through September.By November there were considerably fewer· fi sh in the duwnstream reaches.Si gni fi cantly more pre-sma 1t Dolly Varden char were captured in the upper stream reaches during this time.Fish were observed schooling in mid-stream in -10- I I I I I I I I I I I I I I I I I I I October,behavior which had not been noted previously.Water temperatures during July through September ranged from 5°to goe (41".48°;:),and water temperatures during October and November were substantially lower (Blackett.1968).Armstrong and Elliott (1972)found substant;a1 nurrbers of pre-sma 1t Dolly Varden char in the upper reaches of Hood Bay Creek in late winter where water temperatures were consistently 6"C wanner than in downstream reaches.Armstron9 and Elliott (1972)concluded that warm, 'I ce-free reaches of Hood 8ay Creek attract ovent;oteri n9 pre-smalt Dolly Varden char and that survival rates are higher in the warmer regions.Downstream reaches of Hood Bay Creek become frozen during the winter. Elliott and Reed (1974)and Elliott (1975)determined that pre-smolt Dolly Varden char leave Starrigavan Creek.Southeast Alaska and enter spring-fed tributaries during autumn.The tributaries are characterized by relatively wann winter water temperatures and somewhat stable flows.Immigration of pre-smelt Dolly Varden char and coho salmen to overwintering areas usually corrmenced in September,peaked in early October,and ceased by December.Spates and decreasing water temperatures within Starrigavin Creek appeared to stiTrlJlate movement of fish into these streams. Selection of lotic overwintering habitat by juvenile Dolly Varden char is not well documented. Elliott and Reed (1974)noted that juvenile Dolly Varden char in Spri ng Pond Creek burrowed into 1oggi ng slash and other debri s when water temperatures decreased to 2°C.Fish reappeared when water temperatures rose above about 2°C. Other researchers have noted movement Qf juvenile salmonids when stream wa~er temperatures decrease in the autumn.As water temperatures decrease,fish activity levels and digestion rates -11- drop (Reimers,1957;Chapman and Bjornn,1969).Chapman (1966) stated that the distribution of winter rearing juvenile salmonids in the Pacific Northwest and other temperate areas is probably space related.Fish reduce feeding and seek overwintering areas when water temperatures decrease to or below 5°C.Winter stream conditions,including reduced flows,partial or complete ice-cover and water temperatures at or near freezing do not constitute suitable aquatic habitat for rearing salmonids. Juvenile salmonfds reduce the risk of mechanical injury and displacement by avoiding shallow,cold stream reaches by moving to wanner and deeper stream reaches.burrowing into substrate interstices,or associating with subn~rged logs and root masses. Factors which could adversely affect the winter surviva I of juvenile (pre-~,tlOlt)anadromous Dolly Varden include freezing during streamflow reductions and displacement and injury from dislodged substrate material during spates.The movement of juvenile Dolly Varden to more suitable ove~intering habitat in response to reduced winter streamflows has not been documented. Bustard (1973)reported the ""vement of yay steel head trout (Salmo gairdneri (Richardson))to ove~intering areas in response to altered flows in Carnation Creek,British Colutrbia.Bustard (1973)speculated that yay steel head trout ove~intering within "small rubble,often less that 15 cm in diameter"could be susceptible to injury from substrate movement during spates in Carnation Creek,British Columbia.Hartmann (l96B)found that stable .submerged log jams provide excellent winter habitat for fish,althou9h loose 1099in9 debris which fs susceptible to displacement by flood~is not suitable for salmon1d overwintering habitat. RelOOval of submerged logging debris,natur~lly occurring fallen trees and root masses,and destruction of bankside vegetation and· associated submerged roots could significantly reduce the abundance of juvenile Dolly Varden char in streams where these material s are used for oveniintering habitat.Bustard (1973) -12- ( I I I emphasized the need to identify and preserve overwintering habitat.especially along small intermittent streams that may be overlooked as habitat during timber harvest operations. quality pennanent valuable fish and fish I I I I I I I I I I I Food consumption by pre-smalt Dolly Varden char in overwintering areas is much reduced from summer levels (Armstrong and Elliott, 1972;Elliott and Reed,1974).Annstron9 and Elliott (1972) ascribed the difficulty 1n obtaining juvenile Dolly Varden char by baited minnow traps in the headwaters of Hood Bay Creek to the relatively low water temperatures,SoC to 6.1°C.which influence fish activity. Emigration of pre-smalt 00l1y Varden char from winter to sunrner rearing areas appears to be influenced by water temperature and flo.conditions (Elliott,1975 and 1976).Rising .ater temperatures were assGciated with the emigration of pre-smolt Dolly Varden from Spring Pond Creek.Alaska.Fish emigrated from March or April through June.Floods appear to retard fish emigration within Spring Pond Creek. Emigration of irrmature and mature anadromous Dolly Varden from lakes usually occurs after ice breakup in lakes.Factors.other than the breakup of ice.which could influenc~the timing of fish emigration from lakes include water temperature and streamflow (Annstrong,1965b). Behavioral and physiological changes,collectively tenned smo1tification.and subsequent seaward migration of age 2 to 4 and sometimes older juvenile anadromous Dolly Varden typically occurs in southeast Alaska streams from April to June.Non··lake systems may support an additional autumn smelt migration (Annstrong,1965 and 1970;Annstrong and Ki 55ner,1969). Physiological changes for salinity tolerance.probably begin before seaward migration (Conte and Wagner.1965).Factors -13- I I I I I I affecting timing of smolt1fication are speculative but fish size appears to be influential (Annstrong,1965a).For example. Armstrong (1965)suggested that fish which reach migratory size several months after spring leave streams without lakes.such as Hood Bay Creek,and enter streams with lakes.such ~s Eva Creek. where they overwinter until the following spring.Fish have not been found to migrate seaward from lake-stream systems.such as Eva lake durin9 autumn.Annstrong (1965)speculated that fish that reach migratory size in lakes during the autumn probably overwinter and migrate seaward the fol1owirg spring.Dolly Varden smolts may range in length from about 100 to 180 nm fork len9th (Heiser.1966).Annstron9 (1970)detennined that sprin9 smolts from Hood Say Creek.x·129-134 mm (fl)were considerably smaller than autumn smolts.x •141-146 mm (fl)durin9 1967,1968 and 1969. O.Economic Importance Anadromous Dolly Varden char are an important and sought after sport fish (Morrow.1980). -14- • I I I I I I I I I I I I I I I I I I I I I I I I I II.SPECIFIC HA~ITAT REQUIREHENTS A.Upstream Migration Adult and immature anadromous Do"y Varden char leave the Pacific Ocean and enter various lake and non-lake stream systems from July through December.Various studies have indicated that lake and non-lake streams may support spawning anadromous Dolly Varden char although almost all fish (both spawning and non-spawning) entering non-lake streams such as Hood Bay Creek,Alaska,leave these streams and enter streams with lakes where they overwinter (Armstrong,1963;Armstrong,1965b;Armstrong and Winslow,1968; Annstrong and Kissner.1969).This section will discuss the upstream migration of anadromous fish in non-lake streams. 1.Stream Flow Adult and inmature anadromous Dolly Varden may migrate up non-lake streams f'or varying distances from July through November.Peak nuni:lers of fish have been reported during spates in August and September in Hood Bay Creek (Armstrong, 1967j Armstrong and W~nslow,1968;Armstrong and Kissner, 1969). Peak nulTiJers of fi sh have been recorded enteri ng selected streams during periods of high water in August and September (Armstron9 and Winslow,1968;Armstrong,1969).Upstream fi sh mi grati on may be hi ndered by hi gh current velocities resulting from rapids and culverts.low flows and shallow water depths could also prevent upstream fish passage. 2.Water Temperature Water temperatures coinciding with the corrrnencement,peak and termination of the ;nmigr~tion of anadromous Dolly -15- Varden in Hood Bay Creek.Alaska during 1967.1968 and 1969 were about 4.4 0 to 12.6°C.6.1 0 to II.loC and 3.3 0 to 4.4°C (Armstrong.1967;Armstrong and Winslow.1968;Armstrong and Kissner,1969).Water temperature"s at the end of the inmigration are slightly lower than those during the beginning. 3.Liqht Most Dolly Varden move upstream in Hood Bay Creek at night (Armstrong and Kissner,1969). 4.Current Velocity No information regarding the upstream swinming ability of anadromous Dolly Varden was found in the literature. B.Spawning 1.Current Velocity There are only limited observations of anadromou5 Dolly Varden spawning habitat with respect to current velocity. Bla:kett (1968)reported fish spawning in a reach of Hood Bay Creek,Alaska which had current velocities ranging from 0.3 to 1.2 mlsec (1.0-3.8 ft/sec).Blackett and Armstrong (1965)noted fish (presumably spawning)in a reach of Rodman Creek,southeast Alaska,with a current velocity estimated to be about 0.63 mlsec (2 ft/sec). 2.Substrate Anadromous Dolly Varden typically spawn in small gravels. Blackett (1968)found fish spawning primarily in small gravels,6 to 50 mm in diameter in Hood Bay Creek.Blackett -16- I I I I I I I I I I I I I I I I I I I and Armstrong (1965)observed what appeared to be fish spawning in Rodman Creek,southeast Alaska,in substrate composed of "25%sand and 75%rubble."No substrate classification scheme was presented.Spawning anadromous fish use gravels ranging from 2 to 32 mm in diameter in the Terror and Kizhuyak Rivers,Kodiak Island,Alaska (Wilson et al.,1981). 3.Water Depth The relationship between spawning habitat and water depth is speculative.Blackett (1968)observed spawning fish at depths exceeding 0.3 m whereas Blackett and Armstrong (1965) noted probable spawning activity in a different southeastern Alaska stream in water depths of about 1.25 m. 4.Cover There is little available infonnation on the influence of stream cover on se 1ecti on of spawni ng habitat,however. cover may be a requirement. C.Inmigrant Migration to Overwintering Areas Inmigrant.immature Dolly Varden in non-lake streams such as Hood Bay Creek,A,laska usually leave within several weeks;however, spawners may remain for up to three months (Armstrong.1967). Periods of high water may enhance outmigration of immature and spawned-out Dolly Varden in Hood Bay Creek (Armstrong and Kissner,1969). Immature and spawned-out adult Dolly Varden inmigrate to' overwintering areas of Eva Lake at different times.Inmature individuals entered primarily during July,August and September, and spawned-out adu lts entered in 1ate October and November -17- (Blackett and Armstrong,1965).Most fish passed upstream during periods of darkness. D.Inmi grant Dve"""i nteri ng Areas Lakes,including turbid glacial lakes support ove"""intering populations of juvenile and adult Dolly Varde.,char (Armstrong. 1965b;Schmi dt,Robards and McHugh,1973).The char typi cally remain in Eva Lake from December through mid-March (Armstrong and Blackett,1965).Their distribution within lakes may be quite restricted (Armstrong,1965b;Schmidt et al.,1973). E.Egg and Alevin Development 1.Water Temperature Blackett (1968)determined that anadromaus Dolly Varden eggs hatched in 129 days with 675 thermal units.Absorption of the yolk sac was completed about 65 days later when water temperatures were 2.2°to 2.8°C. F.Summer Juvenile Rearing 1.Water Depth Recently emerged Dolly Varden char typically occupy extremely shallow rivulets.tributaries or streamside margins (Blackett,1968;Armstrong and Elliott,1972).They may occupy deeper stream reaches as they grow (Armstrong and Elliot,1972). 2.Current Velocity Recently emerged Dolly Varden char may occupy extremely shallow.low current velocity stream reaches (Blackett, -18- I I I I I I I I I I I I I I I I I I I 1968:Annstrong and Ell i ot.1972).Mi nnow traps captured juvenile,pre~smolt Dolly Varden char in Hood Bay Creek from a variety of lotic habitat types.The largest juvenile char,about 150 l11l'i fork length,were captured in riffles (Annstrong and Elliott.1972). 3.Instream Cover Juvenile Dolly Varden have been observed in proximity to various forms of instream cover including root balls.trees and undercut banks (Annstrong and Elliott.1972;Wilson.et a1..1981). 4.Substrate Recently emerged fry have been found along stream margins with varying sizes of substrate.shallow depths and very low current velocities (Blackett,1968;Annstrong and Ell lott, 1972).Heiser (1966)noted juvenlle Dolly Varden char occupying ~gravel or muddy substrata"within tributaries of Eva Lake,Alaska. Deposition of significant amounts of fine sediment 1n streams with limited flushing abllities could reduce the quality of juvenile anadromous Dolly Varden rearing habitat. Laboratory stream channels containing unimbedded rubble (0.30 m in diameter)consistently supported <nore juvenile steelhead trout.Salmo gairdneri (Richardson).and chinook salmon.Oncorhynchus tshawytscha (Walbaum).than stream channels containing imbedded rubble and with water temperatures exceedi ng SoC (Bjornn.Brusven t Mol nau. Milligan.Klampt.Chacho and Schaye.1977).8jornn et al. (1977)ascribed the reductions in fish abundance in the channels with imbedded rubble to l~~s of intersticial cover. -19- G.Juvenile Miqration to Overwintering Areas 1.Water Temperatur~ Juvenile (pre-smolt)Oolly Varden char have been reported moving upstream in Starrigavin Creek when water temperatures decreased from about 7·to 4·C.The fish entered Spring Pond Creek,a spri ng-fed tri butary characteri zed by more stable water temp~~atures and flows (Elliott and Reed,1974; Elliott,1975).No fish movement into Spring Pond Creek was noted after Starrigavin Creek water temperatures decreased below 4°C. 2.Stream Flow Freshets within Starrigavin Creek,Alaska appeared to stilYlJlate inrnigration of juvenile Dolly Varden char to Spring Pond Creek (Elliott and Reed,1974;Elliott,1975) until water temperatures decreased below 4°C. H.Juvenile Overwinterinq Areas 1.Water Temperature Fry overwintering areas in southeast Alaskan streams usually have relatively warm water temperatures.Spring Pond Creek, a tributary of Starrigavin Creek,supports overwintering Dolly Varden char.This stream usually has winter water tellllleratures at or above 1.0·C (Elliott and Reed,1974; Elliott,1975). The headwater reaches of Hood Bay Creek also appear to support overwintering juvenile Dolly Varden char.Armstrong and Ell lott (1972)found the greatest numbers of juvenile fish during March and April in headwater reaches of Hood Bay -20- [ [ I I I I I I I I I I I I I I I I I I I Creek where water temperatures were S°to 6.1°(.Downstream reaches were characterized by water temperatures of 3.9°(. Elliott and Reed (1974)noted that Dolly Varden fry hid among substrate interst~ces as water temperatures in Spring Pond Creek decreased to 4°C to 2°C.When water temperatures rose above zoe in March.fish began to move about the stream. 2.Stream Flow Stable winter flow conditions such as those found in Spring Pond Creek.are probably very important to winter survival (Elliott and Reed,1974;Elliott,1975). 3.Substrate Debris and large substrate material may enhance the quality of fish o~erwintering areas.Elliott and Reed (1974)noted juvenile Dolly Varden char burrowing into logging debris and slash when water temperatures decl ined to 4°C or below in SP"j n9 Pond Creek,Alaska. Deposition of fine sediments in streams with 'I imited sediment flushing capabilities could imbed substrate material and significantly reduce the available overwintering habitat for juvenile Dolly Varden char. Experiments of overwinter habitat selection by juvenile chinook and coho salmon and steel head and cutthroat trout. (Salmo clark.i (Richardson»at water temperatures less than SoC indicate that substrate OS-30 em in diameter)with inter'stices devoid of fine sediment consistently supported more fish than substrate imbedded with fine sediment (Bustard,1973;Bjornn et a1.,1977). -21- I.Juvenile Migration to Summer Rearing Areas 1.Water Temperature Juvenile (pre-smolt)Dolly Varden char were found to emigrate from Spring Pond Creek,a spring-fed stream inhabited by overwintering juvenile and adult resident and anadromous Dolly Varden,to Starrigavin Creek when water tem~~ratures rose to 4°to 5°C 1n April 1974 (Elliott, 1975). 2.Stream Flow Elliott (1975)sU9gested that floods in Sprin9 Pond Creek depressed the downstream movement of juvenile Dolly Varden. Fish emigration increased when flows decreased. J.Inmigrant Migration to Sea 1.Water Temperature Most inmature and mature Dolly Varden char (not including smelts)emigrated from Eva Lake Creek,Alaska shortly after ice-breakup.Wa ter temperatures ranged from 4.4°to 6.7°e (Armstron9.1965b). 2.Stream Flow Although ice-breakup in Eva Lake appeared to strongly influence fish migration to the sea.peak numbers of emigrants moved downstream during flood states (Armstrong, 1965b). -22- I I I I I I I I I I I I I I I I I I I K. 3.Light Most Dolly Varden char emigrated from Eva Lake during darkness.During the height of the migration individuals were detected moving downstream during both night and day (Armstrong,1965b). Smalt Migration to Sea 1.Water Temperatures Water temperatures coinciding with the initiation,peak and the near-end of the spring Dolly Varden smolt migration in Hood Bay Creale,Alaska were 3°.5°and 6°C,respectively. during 1967,1968 and 1969 (Armstrong,1970). Water temperatures at the beginning,peak and end of the smalt migration during 1962 and 1963 were 3°,5°and SoC in Eva Lake,and 6·and 10·C in Eva Creek (Armstrong,1970). These values are somewhat similar to water temperatures during the spring smalt outmigration from Hood Bay Creek, Al aska. Dolly Varden smalt stopped migration in mid-June 1957 in the Anchor River,A1as.~a when the water temperature reached 13.3·C (Allin,1957). The autumn smolt mig ation in Hood Bay Creek,Alaska began when water temperatures were 8°C and ended when water temperatures were 6~C during 1967,1968 and 1969 (Armstrong, 1970). -23- 2.Stream Flow Floods apparently influenced the timing of the spring and autumn Dolly Varden cnar sma1t migration in Hood Bay Creek, Alaska.Peak nuni::lers of sma 1ts mi grated downstream duri ng periods of high water (Ann,trang,1970).Smolts have also been noted emigrating from Mendenhall Lake (near Juneau) during the spring and early sunmer.Peak migration5 often coincide with freshets (Bethers,1974). 3.Liqht Most smelt migrate downstream in Hood Bay and Eva Creeks duri"g darkness.a1 though the peak of sma 1t emi grati on i" Eva Creek occurred during both night and day (Armstrong, 1970). -24- I I I I I I I I I I I I I I I I I I I III.CONCEPTUAL SUITABILITY INDEX CURVES Habitat suitability index curves were not constructed for anadromous Dolly Varden char.There were limited data relating the various Dolly Varden 1ife stages to the physi ca 1 and chern;ca 1 character;5ti cs of the hab;ta ts. When data were available.they were often not in a form which could be used to construct habitat suitability curves. -2S- 1'1.DEFICIENCIES IN DATA BASE A 1 imited number of lnvestigations indicate that juvenile anaCiromous Dolly Varden char move to spring-fed reaches of streams with relatively wann water temperatures during the fall and leave these areas the following spring.as evidenced by baited minnow trap samples from Hood Bay Creek (Blackett.1968;Armstron9 and Elliott.1972)and by weir sampling in the Starr;gavin Creek watershed (Elliott and Reed, 19/4;Elliott.1975.1976 and 1977).The Starrigavin .atershed .as affected by tirrber harvest and deposition and removal of logging debris. The relationships between upstream 5winming capabil Hies of juvenile and adult anadromou5 Dolly Varden and current velocity,water temperature,water depth and stream gradient have not been sufficiently investigated.Excessive stream gradient and high current velocities associated with natural stream features or culverts could impede migration of juvenile and adult fish to sumner and winter rearing and spawning areas.The upstream swinming perfonnance of anadromous Dolly Varden is probably influenced by the above factors as well as fish size,spawning condition and,possibly,sex. Lotic habitat selection by spawning anadromous Dolly Varden char is probably collectively influenced by current velocity,water depth, substrate composition and iniJeddedness and instream and bankside vegetation.Few studies have obJectively described the above 10tic habitat condit1ons.If a specif1c area of a stream 1s character1zed by ~ne unfavorable spawning habitat feature,such as excessive current velocity or unsatisfactory substrate composition.that particular area of stream will not be selected by spawning fish despite other favorable habitat conditions. Habitat conditions available for Dolly Varden selection of spawning areas.although. describing this habitat have varied. -26- spawning sites influence methods of objectively For example.within a ----~---- I I I I I I I I I I I I I I I I hypothetical stream.stream reach A may support one pair of spawning fi sn and reach 8.four pa ;rs .These two reaches may conta i n equa t amounts of ·spawning habitat"as defined by Current velocity,water depth and substrate composition and imbeddedness.The difference between the two reaches may be that "spawning habitat"within stream reach A was concentrated in one area and "spawning habitat"within stream reach B was scattered among relatively large substrate and fast water.The non-contiguous distribution of spawning habitat in stream reach B probably allows more fish to spawn because of increased cover and visual isolation.This example illustrates the need to examine entire stream reaches to better understand selection of spawning habitat. The influence of dissolved oxygen levels,rates of intragravel flow, sediment compositions and water temperatures on the sur~ival and development of anadromou5 Dolly Varden char is not understood. Numercus research focusing on the eggs and alevins of other salmonids indicate that the physical and chemical factors exert a substantial and often interactive influence on the survival and fitness on the development stages. Adult and irrmature (post-smalt)Dolly Varden typically overw-inter in lakes.although fish have been found in spring-fed reaches of streams in southeast Alaska.The importance of glacial or glacial-influenced lakes and streams has not been adequately examined.The r~lationships between overwi nteri ng habitat and water depth,current vel oei ty. substrate composition,water temperature and other variables has not been determined.The distribution of overwintering Dolly Varden in selected lakes may be quite restric~ed,although physical and chemical factors which may limit the fish's distribution are not known. Juvenile (pre-smalt)Dolly Varden have been documented moving to spri ng-fed tri butari es and burrowi ng into 1oggi"g debri s when .....a ter temperatures approached 4°C.There were no references found in the literature of juvenile fish using mainstem reaches of rapid-runoff -27- streams for overwintering habitat.The apparent affinity of yoy ar:d older juvenile fish to rapid run-off streams during the sunmer indicates that this type of area could be used for overwintering habitat. There is little available information concerning the lotic sunmer micro-habitat selection by juvenile (pre-smolt)anadromous Dolly Varden char with respect to various physical and chemical lotic habitat variables,food availability and the presence of other fishes. Some investigators have attempted to describe juvenile fish habitat Quantitatively by bankside observation.electro-shocking and baited minnow traps with varying degrees of success.Apparently snorkel ing has not been used for fish observation in clearwater streams. Snorkeling has been shown to be a valuable fish observation technique in clearwater streams of the Pacific Northwest and the midwest (Everest and Chapman,1972;Fausch,1978). Some work has focused on the feeding habits of juvenile (pre-smolt) fish occupying mainstem versus stream margins but no drift or benthos sampling was done to fOrrJIJlate "forage ratios.-Few observations of the feeding behavior of juvenile Dolly Varden char have occurred in streams except for yay fish in very shallow,low current veiocity areas along stream margins. Some observati ons of juvenil e coho sa 1mon and 00 11 Y Varden char have occurred in aquariums and streams.The behavior of juvenile Dolly Varden char and other salmoni~s occurring in the same regions has not been studied adequately. -28- _.._.------ I I I I I I I I I I I I I I I I I I I V.RECOMMENDATIONS AND FURTHER STUDIES Studies should be designed and conducted to detennine the survival, movements and behavior of all life stages of anadromoU5 Dolly Varden char with respect to physical,chemical and biological habitat components within selected pristine Alaska drainages.The above relationships should be examined thoroughly both within the drainage and by supplemental laboratory and field studies prior to the occurrence of any land use activities which could modify the habitat. Several years of study could be required to meet this objective. Investigations should continue during and after land use activities to adequately man;tor the fi sh 1 ife stage-habitat relationshi ps.Such research and 5UPP 1ementa 1 1abora tory and fi e 1d studi es cou 1d provi de land managers with needed information to protect and enhance anadromous Dolly Varden habitat. Field and laboratory studies should be designed and conducted to determine the upstream swimming capability of immature (pre and post-smelts)and gravid and spawned-out adult anadromous Dolly Varden char in relation to current velocity,water depth,water temperature, stream gradient and length of potential migration barriers.Studies could be similar to those described by iolacPhee and Watts (1976)for testing Arctic grayling swimming performance.Results of these tests could be used fer determining the best methods for installing culverts to allow fish migration and to designs of culverts and other fish passage facilities. Str.dies should be designed and conducted to evaluate the influence of wdter temperature.dissolved oxygen,rate of intragravel flow, substrate composition and possibly other physical and chemical habitat 'I,ri ab 1es on the survi va 1 and deve 1opment of anadromous Dolly Varden :har eggs .1nd alevins and the fitness and survival of emergent fry. Controlled environmental laboratory tests should complement field studies. -29- Standardized methods should be developed and evaluated to objectively describe current velocity,water depth.substrate composition and irrbeddedness.instream and banksid'e cover and water temperatures at anadromous Dolly Varden spawning sites.The above 10tic habitat data collected at a number of redds within a stream or stream reach could be exami ned by frequency ana lys is for each loti c habitat component. These frequency analyses would help describe lotic hillbitat selection by spawning fish.in relation to current velocity.water depth. substrate composition and imbeddedness and possibly other lotic habitat -,arlables.The frequency analyses would not determine fish spawning habitat preferences because streams and stream reaches are characterized by a finite combination of acceptable habitat variables. Readers are urged to consult Appendix III of the Terror Rher,Alaska Instream Flow Report by Wilson et al.(198)which discusses fish spa~ning habitat selection and the assumptions associated with habitat suitability curve construction. Standardized methods should be developed and refined to evaluate current velocity.water depth.substrate composition and imbeddedness and instream and bankside cover at anadromous char spawning sites to better understand habitat selection within individual streams or stream reaches.For examp 1e.loti c habitat types cou 1d be characterized by current velocity,water depth,instream and banks ide cover conditions within those ranges measured at redds.Measurements of substrate composition and imbeddedness which were not used for spawning habitat by anadromous llolly varden char could help us to, better understand spawning habitat selection of this fish in various streams. Weirs should be used to monitor juvenile (pre-smelt)anadromous Dolly Varden char movements in relation to streamflow.water temperature and other phys ica 1 and chemi ca 1 habi tat variables in sma 11.i ntenni ttent and larger streams within a drainage.Snortling and minnow trapping could supplement sampling with weirs. -30- I I I I I I I I I I I I I I I I I I I Stud;es shou 1d be des i gned and conducted to desc:ri be sunmer habitat selection by juvenile {pre-smalt}anadromous Dolly Varden char with respect to a variety of physical and chemical habitat variables,food ava il ab il i ty and the presence of other fi sh.Invest i 9a ti ons us;ng snorkling for fish observation should be conducted in cleanotater streams using techniques similar to Everest and Chapman (l972)and Fausch (l978).Fish holding positions should be characterized by water depth,distance to streambed.lighting,substrate composition and ;mbeddedness,1nstream and banks 1de cover.current ve 1acity and prox imity to other f1 sh •i ne 1udi n9 char and other spec;es.These investigations would complement fish movement studies along streams supporting weirs. Studies of fish feeding behavior coupled with benthos and drift sampling and fish gut analysis should be conducted to better understand the feeding habits and apparent affinity of Dolly Varden char to the substrate. More investigations should occur to detect and characterize overwi nteri ng habi tat se 1ecti on by va rious ages of juvenil e (pre-smalt)anadr~mous Dolly Varden char with respect to ~ater depth, current ve 1ocity,wa ter temperature.overhangi ng vegetati on.undercut banks,substrate material and proximity to stream margins. Identification of over\lintering fish habitat is required for the protection of this fish species.Various land use activities could significantly reduce the quality of this habitat (Bustard,1973). Habitat enhancement efforts should be formulated with an understanding of what constitutes good ove~intering habitat for various ages of Dolly Varden char. LfJOratory and field tests,somewhat similar to those conducted by Bustard (l973).should be designed and conducted to complement studies· of the distribution and behavior of overwintering anadromous Dolly Varden in selected streams.These tests should provide juvenile fish with a continuum of overwinter habitat types from no cover to total -31- riparian cover.unimbedded to totally imbedded substrate of sand to large cobble substrate and a variety of water temperatures.Juvenile fish of various ages should be tested because fish size may influence overwinter habitat selection. Studies should be designed and conducted to determine the presence of overwintering immature (post-smolt)and adult anadromous Dolly Varden char in clearwater and glacial lakes and streams.The distribution of oveNi nteri ng fi sh in 1akes can be quite limited.Studi es of loti c overwi nteri ng areas with respect to va rious phys i ca 1 and chemi ca 1 habitat conditions should be conducted to explain habitat selection criteria and to predict fish overwintering areas by the character of the habitat. Radio telemetry should be considered as a viable technique to monitor movements of immature and adult anadromous Dolly Varden char in overwintering areas which are difficult to sample by gillnet or other methods. -32- I I I I I I I I I I I I I I I I I I I VI.LITERATURE CITED Alderdice.D.,W.Wickett and J.Brett.1958.Some effects of temporary low dissolved oxygen levels on Pacific salmon eggs.J.Fish.Res. Board Can.15(2):229-250. Allin.R.1954.Stream survey of Anchor River.Game Fish Investigations of Alaska.Quarterly Progress Report,Federal Aid in Fish Restoration Project F-I-R-4.Alaska Game Commission 4:47-66. Alt,K.1978.Inventory and catalogi~g of sport fish and sport fish wate~s of western Alaska.Alaska Dept.of Fish and Game.Federal Aid in Fish Restoration,Annual Progress Report,1977-1978. 19(G-I-P):36-60. Armstrong,R.1963.Investigations of anadramous Dolly Varden populations in the Lake Eva-Hanus Bay drainages,southeastern Alaska.Alaska Dept.of Fish and Game.Federal Aid in Fish"Restoration.Annual Pro9ress Report,1962-1963.Project F-5-R-4:7B-122. Armstrong,R.Ig65a.Some feeding habits of the anadromous Dolly Varden, Salvelinus malma (Walbaum)in southeastern Alaska.Alaska Dept.of Fihs and Game Informational Leaflet 51:1-27. Armstrong,R.1965b.Some migratory habits of the anadromous Dolly Varden, Salvelinus malma (Walbaum)in southeastern Alaska.Alaska Dept.of Fish and Game Research Report 3:1-26. Armstrong,R.1967.Investigation of anadromous Dally Varden populations in the Hood Bay drainages,southeastern Alaska.Alaska Dept.of Fish and Game.Federal Aid in Fish Restoration.annual Progress Report. 1966.Project F-5-R-8:33-56. Armstrong.R.1970.Age,food and migration of Dolly Varden smelts in southeastern Alaska.J.F"ish.Res.Boerd Can.27:991-1004. -33- Armstrong,R. malma)in 1974.Migration of anadromaus Dolly Varden (Salvelinus southeastern Alaska.J.Fish.Res.Board Can.31:435-444. Armstrong,Rand S.Elliott.1972.A study of Dolly Varden in Alaska. Alaska Dept.of Fish and Game.Federal Aid in Fish Restoratio1, Annual Progress Report,1971-1972.Project F·9-4-13:1-34. Armstrong,R.and P.Kissner.1969.Investigations of anadromous Dolly Varden populations in the Hood Bay,southeastern Alaska.Alaska De~t. of Fish and Game.Federal Aid in Fish Restoration,Annual Pro9rf~ss Report,1968-1969.Project F-5-R-l0:45-92. Armstrong,R.and R.Winslow.1968.Investigation of anadromaus Dolly Varden populations in the Hood Bay drainages,southeastern Alas<a. Alaska Dept.of Fish and Game.Federal Aid in Fish Restorat;Jn, Annual Progress Report,1967-1968.Project F-S-R-9:45-80. Sethers,M.1974.Mendenhall Lakes salmon rearing facility.Alas5a De)t. Fish and Game.Federal Aid in Fish Restoration,Annual Report of Progress 1973-1974,Project F-9-6.15(AFS-43). Bjornn,T.,M.Brusven,M.Molnau,J.Miiligan,R.Klampt,E.Chacho and C. Schaye.1977.Transport of granitic s~diment in streams and its effects on insects and fish.For Wildlife and Range Exp.,Str.., Completion Rep.Water Resour.Res.Inst.Project B-036-1D,~. University of Idaho,Moscow.43 p. Blackett,R.1968.Spawning behavior,fecundity and early life history (f anadromous Dolly Varden,Salvelinus malma (Walbaum)in southeastern .Alaska.Alaska Dept.of Fish and Game,Research Report 6:1-85. -34- I "I I • • I I • • • • • • • • • • • • • • • Blackett,~.and R.Armstrong.1965.Investigations of anadromous Dolly Varden ;::Gj:'ulations in the lake Eva-Hanus Bay drainages.southeastern Aiaska.Alaska Dept.of Fish and Game.Federal Aid in Fish ~estoration.Annual Progress Report,1964-1965.Project F-5-R-6:23-56. Bustard,O.1973.Some aspects of the winter ecology of juvenile salmonids with reference to possible habitat alteration by 1099in9 in Carnation Creek,Vancouver Island.M.S.thesis.Univers)ty of British Columbia.Vancouver,B.C.85 p. Chapman,O.i966.Food and space as regulators of salmonid populations in streams.Am.Nat.100:345-357. Chapman.O.and T.Bjornn.1569.Distribution of salmonids in streams, wHh sped a1 reference to food and feed;"9.H.R.MacMillan Lectures in Fisheries.Symposium on salmon and trout in streams.University of British Columbia.p.153-176. Coble,O.1961.Influence of water exchange and dissolved oxygen in redds on survival of steel head trout _ryos.Trans.Am.Fish.Soc. 90(4):469-471. Conte,F.and H.Yoagner.1965.Development of osmotic and ionic regulation in juvenile steel head trout,Salmo gairdneri.Camp. Biochem.Physiol.14:603-620. Elliott,S.1975.Ecology of rearin9 fish.Alaska Dept.of Fish and Game.Federal Aid in Fish Restoration,Annual Progress Report, 1974-1975.Project F-9-7{D-I-B):23-46. Elliott,S.1976.Ecology of rearing fish.Alaska Dept.of Fish and Game.Federal Aid in Fish Restoration,Annual Progress Report, 1975-1976.Project F-9-8(D-I-B):21-44. -35- Elliott.S.1977.Ecology of rearing fish.Alaska Dept.of Fish and Game.Federal Aid in Fish Restoration,Annual Progress Report, 1976-1977.Project F-9-9-(0-I-B):25-36. Elliott,S.and W.Oinneford.1975.Establishment of guidelines for protection of the sport fish resources during logging operations. Alaska Dept.of Fish and Game.Federal Aid in Fish Restoration. Annual Report of Pro9rESS.1974-1975.Project F-9-7.16(0-I-A).1-22. Elliott,S.and R.Reed.1974.<cology of rearing fish.Alaska Dept.of Fish and Game.Federal Aid in Fish Restoration.Annual Prorress Report.1973-1974.Project 5-9-6(0-I-B):9-43. Everest.F.H.and D.W.Chapman.1972.Habitat selection and spatial by juvenile chinook sallJl:m and steel head trout in two 'daho strei..,llS.J. Fish.Res.Board Can.29:91-100. Fausch.K.O.1978.Competition between resting positions in a stream. University,East Lansing,Michigan. brook and ra 1nbow trout for M.S..thesis.Michigan State 100 p. Hartmann.G.1968.Growtn rate and distribution of some fishes in the Chill iwack.Scuth Alouette and Salmon Rivers.B.C.Fish and Wildl. Branch.Mgmt.Publ.No.11.33 p. Heiser,D.1966.Age and growth of anadromous Doliy Varden char, 5alvelinus malma (Walbaam),in Eva C~k,Baranof Island,southeastern Alaska.Alaska Dept.of Fish and Game.Research Report 5:1-29. Koski,K.1966.The survival of coho salmon (Oncornyr,chus kisutr.hi from egg depos i ti on to emergence in thrtl!Oregon coas.ta 1 streams.M.S. thesis.Oregon State Univer~ity.Corvalis,Oregon.34 p. -36- I Mctlell ,W.1966.Affect of the spawning bed envi ronment on reproduction of pink and chum salFi'On.U.S.Fish and Wildl.Servo Fish.Bull. 65:<95-5lJ. biology of the M.S.thesis. Legset.J.1959.The reproductive (Salvelinus malma (Walbaum)). Victoria,B.C.111 p. McNeil,W.a,nd W.Ahnel1.1964.Success to size of spawning bed materials. Sr.i.Re.Fish.No.469.15 p. Dolly Varden char University of Victoria, of pink salmon spawning relative U.S.Fish and Wildl.Servo Spec. "I !I I I .1 I r~orrow,J.19BO.The freshwater fishes of Alaska.Alaska Northwest Pub. Co.,Anchorage,Alaska.248 p. MacPhee,C.and F.Watts.1976.Swirrming performance of Arctic grayl ing in highway culverts.Final Report to U.S.Fish and Wildlife Service, Anchorage,Alaska.Contract 14-16-001-5207.41 p. Re~d,R.and R.Anmstrong. area.Alaska Dept. Restoration,Annual 12:1-105. 1971.Dolly Varden sport fishery -Juneau of Fish and Game.Federal Aid in Fish Pro9ress Report,1970-1971.Project F-9-3, I \I '1 I I Rp.imers,N.1957.Some aspects of the relation between stream foods and trout survival.Calif.Fish and Game.43{l):43·69. Reiser,D.and T.Bjornn.1979.Habitat requirements of anadromous salmon ids -Influence of forest and rangeland management on anadromous fish habitat in the western United States and Canada.U.S.O.A.Forest Service.Gen.Tech.Rep.PNW-96.Pacific Northwest Forest and Range Exp.Stat.Portland,Oregon.S4 p. -37 - II 1\ 1\ II II rI [I I I I I I I I I I I I I I I I I I I II Schmidt.A.,S.Robards and M.McHugh.1973.Inventory and cataloging cf sport fish and sport fish waters 1n southeast Alaska.Alaska Dept.of Fish and Game.Oederal Aid in Fish Restoration,Annual Progress Report,1972-1973.Project F-9-5,14:1-62. Scott.'Ii.and E.Crossma'l.1973.Freshwater fishes C'f Canada.8u11.184. Fish.~e!.Soad of Can .•Ottawa.966 p. Sheridan.W.1962.Waterflow through a salmon spawning riffle in southeastern Alaska.U.S.Fish and '~i1dl.Servo Spec.Sci.Rep.Fish No.407.22 p. Sl1ve,..S.•C.Warren and P.Deudaroff.1963.Dissolved oxygen requirements af developing steel head trout and chinook salmon embryos at different water velocities.irans.Am.Fish.Soc.92(4):327-343. Vaux,W.A.1962.Interchange of str~am and intragravel water in a salmon spawning riffle.U.S.Fish and Wildl.Servo Spec.Sci.Rep.Fish No. 405.11 p. Wickett.W.1958.Review of certain environ~~ntal factors affecting the production of pink and chum salmon.J.Fish.Res.Board Can. 15(5):1103-1126. Wickham.G.1967.Physical microhabitat of trout.M.S.thesis.Colorado State University.Fort Collins.42 p. Wilson.101 .•E.Trihey.J.Baldrige.C.Evans.J.Thiele and D.Trudgen. 1981.An assessment of environmental effects of construction and operation of thp.proposed Terror lake hydroelectric facility.Kodiak. Alaska.Instream '10'1 studies final report.Arctic Environmental Information and Da~3 Center.University of Alaska.Anchorage.Alaska. 419 p. -38- STLAWRENCE ~AND 0 MAIN STUDY SITES IIJ HOOD BAY CREEK [i) RODMAN CREEK 00 EVA LAKE ~ STARRIGAVIN CREEK ALEUTIAN ISLANDS 0 • ..,::?~ " 0 ~Jt:/)' DISTRIBUTION OF DOLLY VARDEN -SAL VEL/NUS MALMA (WALBAUM) FROM SCOTT AND CROSSMAN 1973, AND MAIN STUDY SITES.