7D-A151 198 SPECIES PROFILES: LIFE HISTORIES AND ENVIRONMENTAL i/iREQUIREMENTS OF COASTR..(U) GEORGIA COOPERATIVE FISHERYRESEARCH UNIT ATHENS D S DRNIE ET AL. JUL 84

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FWSIOBS*8 12 TR EL-82-4July 1984

Species Profiles: Life Histories and y IIEnvironmental Requirements of Coastal Fishes ELECTEand Invertebrates (North Atlantic) C MAR 13 31985

ATLANTIC SALMON

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FWS/OBS-82/11.22TR EL-82-4July 1984

Species Profiles: Life Histories andEnvironmental Requirements of Coastal Fish and Invertebrates

(North Atlantic)

ATLANTIC SALMON

by

Dwight S. DanieJoan G. Trial

andJon G. Stanley

Maine Cooperative Fishery Research Unit ..313 Murray Hall

University of MaineOrono, ME 04469

Project Manager .Larry Shanks

Project OfficerNorman Benson

National Coastal Ecosystems TeamU.S. Fish and Wildlife Service

1010 Gause Boulevard -D T-CSlidell, LA 70458 ELECTE

This study was performed for 3JCoastal Ecology Group

U.S. Army Corps of EngineersWaterways Experiment Station I;;*. .

Vicksburg, MS 39180

and

National Coastal Ecosystems TeamDivision of Biological Services

Research and DevelopmentFish and Wildlife Service

U.S. Department of the Interior

Washington, DC 20240

DISThR1UMION STATEMENT A!Appw,,d im pubh relo n".-

Distribution Unlimited

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This series should be referenced as follows:

U.S. Fish and Wildlife Service. 1983-19 . Species profiles: life historiesand environmental requirements of coastal fishes and invertebrates. U.S. FishWildl. Serv. FWS/OBS-82/11. U.S. Army Corps of Engineers, TR EL-82.-4.

This profile should be cited as follows:

Danie, D. S., J. G. Trial, and J. G. Stanley. 1984. Species profiles: l ife *K-histories and environmental requirements of coastal fish and invertebrates__(Aorth Atlantic) -- Atlantic salmon. H.S. Fish Wildl. Serv. FWS/OBS-82/11.22.U.S. Army Corps of Engineers, TR EL-82-4. 19 pp.

Ile

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PREFACE

This species profile is one of a series on coastal aquatic organisms,principally fish, of sport, commercial, or ecological importance. The profilesare designed to provide coastal manayers, engineers, and biologists with a briefcomprehensive sketch of the biological characteristics and environmental require-ments of the species and to describe how populations of the species may beexpected to react to environmental changes caused by coastal development. Eachprofile has sections on taxonomy, life history, ecological role, environmentalrequirements, and economic itnportance, if applicable. A three-ring binder isused for this series so that new profiles can be added as they are prepared. Thisproject is jointly planned and financed by the U.S. Army Corps of Engineers andthe U.S. Fish and Wildlife Service.

Suggestions or questions regarding this report should be directed to:

Information Transfer SpecialistNational Coastal Ecosystems TeamU.S. Fish and Wildlife ServiceNASA-Sl1idel 1 Computer Compl ex S1010 Gause Boulevard -

Sl idellI, LA 70458

or

U.S. Army Engineer Waterways Experiment StationAttention: WESERPost Office Box 631Vicksburg, MS 39180

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CONTENTS

Page

PREFACE..............................iii 0CONVERSION TABLE...........................vACKNOWLEDGMENTS .. .. ..... ...... ...... ..... ...... vi

NOMENCLATURE/TAXONOMY/RANGE. .. .... ..... ...... ..... ... 1MORPHOLOGY/IDENTIFICATION AIDS. .. ...... ..... ...... .... 2REASON FOR INCLUSION IN SERIES. .. ...... ...... ..... .... 3 0LIFE HISTORY .. .... ........... .. ...... ...... ..... 3Spawning .. . ... ... ... .. ... ... ... ... .. ...... 3Fecundity and Eggs. .. ...... ...... ..... ......... 3 '-

Larvae and Juveniles. .. ...... ...... ..... ......... 5Smolts and Sea Migrants. .. .... ..... ...... ...... ... 6Sea Life and Homeward Migration .. .. ..... ...... ......... 6-

GROWTH CHARACTERISTICS .. .... ...... ..... ...... ...... 7COI44ERCIAL/SPORT FISHERIES .. .... ...... ..... ...... ... 9ECOLOGICAL ROLE .. .. ..... ...... ...... ..... ...... 11

Food Habits .. .. ...... ..... ...... ..... ....... 11Predation .. .. ..... ...... ...... ..... ......... 11

ENVIRONMENTAL REQUIREMENTS. .. ...... ...... ..... ...... 12Temperature .. .. ...... ..... ...... ..... ....... 12Dissolved Oxygen .. .... ...... ..... ...... ........ 12- -

pH. .. ...... ..... ...... ..... ...... ...... 12Depth and Velocity .. .... ..... ...... ...... ...... 13 -

Light. .. .... ..... ...... ..... ...... ........ 13 .

Salinity .. .... ...... ..... ...... ..... ...... 14Substrate, Sediment, Turbidity .. .... ...... ..... ...... 14

LITERATURE CITED .. .... ...... ..... ...... ......... 15

iv

0

CONVERSI ON FACTORS

Metric to U.S. Customary

Mul tiply By To Obtain

millimeters (mm) 0.03937 inchescentimeters (cm) 0.3937 inchesmeters (m) 3.281 feetkilometers (kia) 0.6214 miles

square meters (m2 ) 2 10.76 square feetsquare kilometers (km) 0.3861 square mileshectares (ha) 2.471 acres

liters (1) 0.2642 gallonscubic meters (m3) 35.31 cubic feet .

cubic meters (m3) 0.0008110 acre-feet

milligrams (mg) 0.00003527 ouncesgrams (g) 0.03527 ounceskilograms (kg) 2.205 poundsmetric tons (t) 2205.0 pounds

9 metric tons 1.102 short tonskilocalories (kcal) 3.968 British thermal units

Celsius degrees 1.8(C,) + 32 Fahrenheit degrees

U.S. Customary to Metric

inches 25.40 millimetersinches 2.54 centimetersfeet (ft) 0.3048 metersfathoms 1.829 metersmiles (mi) 1.609 kilometersnautical miles (nmi) 1.852 kilometers

square feet (ft ) 0.0929 square metersacres 0.4047 hectaressquare miles (m 2) 2.590 square kilometers

gallons (gal) 3 3.785 literscubic feet (ft ) 0.02831 cubic meters 0acre-feet 1233.0 cubic meters

ounces (oz) 28.35 gramspounds (lb) 0.4536 kilogramsshort tons (ton) 0.9072 metric tonsBritish thermal unit (BTU) 0.2520 kilocalories

Fahrenheit degrees 0.5556(F0 - 32) Celsius degrees

.. ~~. . -. . . o-.

_VI

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0

ACKNOWLE DGMENTS

We thank Kenneth F. Beland, Maine Atlantic Salmon Commission, Machias;Edward T. Baum, Maine Atlantic Salmon Commission, Bangor; and Alexis E. Knight,U.S. Fish and Wildlife Service, Laconia, New Hampshire, for review of the manu-script and for suggestions of additional material for inclusion in the text.

OW X

vi

- . -- . . . . . L ..

Figure 1. Adult Atlantic salmon.

ATLANTIC SALMON

NOMENCLATURE/TAXONOMY/RANGE lantic, they range from Iceland,southern Greenland and Ungava

Scientific name ........ Salmo salar Bay, Quebec, to the ConnecticutCommon name ....... Atlantic salmon River (Scott and Crossnan 1973).Other common names . . . Ouananiche,

Kennebec salmon, landlocked salmon, Anadromous Atlantic salmon onceSebago salmon. French common names: inhabited North American streamsSaumon atlantic, saumon d'eau douce, along the Atlantic coast, perhaps -•

bratan as far south as the Hudson River,Life stage names .......... .Parr New York, and the St. Lawrence -

(freshwater juvenile), smolt (juve- River tributaries including Lakenile migrating to sea), grilse (Fig- Champlain and Lake Untario.ure 1) (adult returning to fresh- Anadromous populations are nowwater to spawn after 1 year at sea), restricted to rivers from Connec-bright salmon (adult returning after ticut northward to Ungava bay, S2 or more years), kelt or black sal- Quebec, and in Labrador as farmon ( a postspawning or spent adult) north as the Fraser River, Nain(Allen and Ritter 1977). Bay. In Greenland they inhabit

Class ... .......... Osteichthyes the Kapisigdlit River at the headOrder ............ .Clupeiformes of Godthab Fjord northward fromFamily .... .......... Salmonidae Kap Farvel to Umanak on the west

coast and to Angmagssalik on the SGeographic range: The Atlantic salmon east coast (McCrimmon and bots

is indigenous to the North Atlan- 1979). Attempts to restoretic Ocean basin (Figure 2). anadromous populations to theTheir range in the eastern Connecticut, Merrimack, Penob-Atlantic extends from the Arctic scot Union and Pawcatuck RiversOcean to Portugal, including the in New England, primarily by ADBaltic Sea. In the western At- stocking hatchery-raised parr

. -. . . . . . . . . . . . . . .

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and smolts, have been partially to posterior margin of pupil when 1b2successful. The range of land- mm long, and seldom to posterior mar-locked populations in Maine, New gin of eye except on mature males,Brunswick, and Nova Scotia has which develop a pronounced hook orbeen extended. In Maine, for kype on lower jaw. Well-developedexample, landlocked Atlantic teeth on upper and lower jaws (pre-salmon endemic to only four maxillary, maxillary, dentary); fewwatersheds, have been trans- teeth in a single row on shaft of vo-planted to hundreds of lakes. mer and palatines, on tongue in two

rows; no hyoid teeth. Total gillraker count, 15-20. Branchiostegal

lk rays usually 11-12 (rarely i or 13).Fins: adipose present posterior todorsal, dorsal, 10-12; anal, 8-11; Sventral, 9-10, with a distinct pelvic

Faroe Le axillary process; pectoral, 14-lb.4. Ireland Caudal with shallow fork. Scales cyc-icland foid, 109-121 in lateral line, 1U-13

I(eln from posterior edge of adipose base to

D Ilateral line; lateral line decurvedanteriorly, straight posteriorly. Py-

$ loric caeca, 40-74. Vertebrae, b8-bl(Scott and Crossman 1973).

Pigmentation: Color varies with

age, environment, and life stage.,,fou/and Small parr have 8 to 11 pigmented bars

alternating with a single row of redulf of Main. spots along the lateral line on each

side. Migrating smolts and adults atsea are silvery on the sides and bel-ly, but the adults have brown, green,

Figure 2. Worldwide range of Atlantic or blue coloration on the back andsalmon and migratory routes (Netboy numerous black spots, usually x- 4011974). shaped, scattered along the body, more

numerous above the lateral line. Afew of these spots are also located on

MORPHOLOGY/IDENTIFICATION AIDS the head. Landlocked adults have morenumerous and larger spots than anad- %

Body elongate, somewhat compres- romous salmon (called bright salmonsed laterally, greatest body depth at when first entering fresh water). Atdorsal fin origin or slightly poster- spawning, pectoral and caudal fins be-ior to dorsal fin, 18% to 22% of the come blackish and both sexes take on atotal length. Head length about equal bronze to purple coloration and mayto or slightly greater than body acquire reddish spots on the head anddepth, 20% to 23% of the total length, body. After spawning, the survivingbut most variable during modifications adults (kelts) are dark colored.of head structure during spawning.Eye moderate, 14% to 19% of head Distinctions: Dark spots on alength (variable depending on growth light background distinguish Atlanticrate); snout rounded, its length salmon from light spotted chars (brookgreater than eye diameter for fish trout and Arctic char), which haveover 305 mm long; mouth terminal, light spots on a dark background (Leimlarge, maxillary extending posteriorly and Scott 1966). Atlantic salmon also

2

have larger scales, and have teeth on range between 4.40 and 5.b°C (DeCola

the shaft of the vomer. They may be 1970). The male aligns himself withdistinguished from rainbow trout by the female and fertilizes the eggs asthe absence of serial rows of black they are deposited into each pit (Jor-spots on caudal fin and from brown dan and Beland 1981). Some male parrtrout by the shorter maxillary, nar- become sexually mature and take anrower peduncle, lack of red on the active part in fertilizing eggs. Theadipose, and larger scales. Species female then covers the eggs with aboutof introduced Pacific salmon are dis- 10-25 cm of the gravel excavated whiletinguished by the larger number of building another pit just upstream.anal fin rays, 12-19, whereas the At- This process is repeated until spawn-lantic salmon has 8-11. ing is completed.

Fecundity and EggsREASON FOR INCLUSION IN SERIES

Fecundity depends largely on bodyThe anadromous Atlantic salmon size. For example, anadromous Atlan-

has high social and economic value be- tic salmon produce more eggs than thecause of its mystique as a sport fish landlocked form because its femalesand the high quality of its flesh. are larger. A rule of thumb is that ,Once relatively widespread, this anadromous females produce 1,bUU tospecies is now restricted to several 1,800 eggs/kg. Rounsefell (19b7) re-rivers of New England (Figure 3), ported that females weighing about bwhere dams, pollution, and fishing kg produced about 1,800 eggs/kg. Popehave excessively reduced reproductive et al. (1961) used the following for-potential. During the egg, larval, mula (modified by Baum and Meisterand parr stages, this salmon is 1971) to estimate the number of eggsespecially vulnerable to the conse- produced by fish with different bodyquences of coastal development pro- lengths:jects; therefore knowledge of the lifehistory and environmental requirements LOgloN 2.69 logiUL U.15of this species is essential for deci- Lg".269o 'L- 'lsions that will assure its continued Eggs are spherical, b-7 mm in •existence and enhancement. diameter, and pale orange or amber.

The eggs are slightly adhesive initi-ally and stick to the substrate in the

LIFE HISTORY pit until they are covered with grav-el. The incubation period varies with

Spawning stream temperature. In Maine the eggshatch in April or early May after 17b S

Atlantic salmon spawn during the to 195 days under normal winter condi-period of mid-October to mid-November tions (Jordan and Beland 1981). Anin gravel areas of freshwater streams incubation of 110 days at 3.9'C cited(Bigelow and Schroeder 1953). Spawn- by Leim and Scott (1966) probably ising sites are located at the down- for hatchery eggs.stream end of the riffles with water

percolation through the gravel or at Egg size is influenced by theupwellings of groundwater. Redds are age, size, and physiological conditionconstructed by the female using her of the female. Egg size is also ae-caudal fin in a fanning motion. A termined by the length ot time theredd consists of several depressions female lives in the ocean, the time ofor pits excavated from the stream spawning, and the position of the eggbottom (Leim and Scott 1966). Water in the ovaries. Average egg weight istemperatures during spawning usually 164 mg. The rate of embryo develop-

3

. . . o.. .* .

-, CANADA

0 MAINE

~' PENOBSCOT R.

PASSAGAS-SAWAKEAG R. 0 ~ ~ Ari

SHEEPSCOTSR

LU PLEASANT R.of I

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PORTLAND - 4 -

ATrLANTIC OCEAN N

BOSTON MILES0so 100

0 50 110

CAPE COD KILOMETERS

MASS.

Figure 3. Rivers supporting Atlantic salmon in the North Atlantic Region. .-

4

nent is not affected by egg size, but Chadwick (1982) also related year -?mbryo size is larger in larger eggs class strength of smoits to eygind the resulting larvae have higher deposition in three New Brunswick;urvival (Kazakov 1981). Egg size streams with the equation:increases with fecundity and size ofFemales (Pope et al. 1961). in Y 1.29 In X - 8.U14

Larvae and Juveniles where X is the number of eggs (thou- 0sands) and Y is the number of smolts

After hatching, the eleuthero- of that year class.embryos (alevin or yolk-sac larvae),about 15 mm long, remain buried in the On reaching a length of about 4Ugravel absorbing their yolk sacs for mm during the first summer, youngnourishment for about 6 weeks (Bigelow salmon are called parr or fingerlings.and Schroeder 1953). When the yolk These juvenile salmon are found pre- 0sacs are fully absorbed, the 25-mm fry dominately in riffle sections ot thebegin to forage for food in the sub- stream. Young parr are more numerousstrate, and then emerge from the sub- in rapidly flowing water during thestrate. In a Maine stream, between May day and early evening. At night they12 and 28 emergence was always at rest on the bottom in the quieter wa-night (Gustafson-Marjanen 1982). In ters (Gibson 196b). Older parr areNew Brunswick streams, peak emergence residents of the deeper pools inand dispersal were between June 12 and streams. They defend territories ana23 (Randall 1982). After emergence, attack other parr entering the detend-fry disperse and immediately establish ed zone. This practice allocatesterritories. The competition for ter- space and food to ensure adequateritory may limit the number of fish in growth and reduce predation by otherthe population. The young salmon. are species (Gustafson-Marjanen 198Z).also displaced downstream by water Parr frequently move upstream orflow. By late summer population den- downstream, perhaps as the result ofsity of parr is usually less than aggressive interactions, and some parr50/100 M 2 , but may be as much as may migrate to tributaries previously370/100 m 2 in New Brunswick (Francis unpopulated with salmon. In New1980). Brunswick streams abundance is usually

less than 15/100 m 2 but in a tewOf the eggs deposited, only about streams may be as high as bZ/IUU

5% result in production of fry. Mor- M2 (Francis 198U).tality rates also are high duringemergence and dispersion (Ottaway and In the fall, many male parr be-Clarke 1981). Egg-to-fry survival in come sexually mature (precociousNewfoundland streams was influenced by parr), ensuring a mixture of breeding 0winter temperatures and change in stock (Refstie et al. 1977). Parrwater levels described by Chadwick remain in the stream until they are -(1982) in the equation: 125-150 mm length, which may take up

to 2-3 years; they remain in streams

Nfry/Neggs = 68.07 + 1.89X - 0.005Y until they are 18U mm long and 4-8years old in the Ungava Bay region ot

where X = the lowest mean monthly tem- Canada (Schaffer and hUson 197b). Sperature (°C) and Y = the difference Parr that tail to reach the criticalbetween the November mean discharge length by spring or early summer inand the lowest winter mean monthly any one year do not transform intodischarge (1/sec). Egg-to-parr sur- smolts until the following spring,vival in Cove Brook, Maine, was 10% regardless of subsequent growth(Meister 1962). (Refstie et al. 1977). If smolts are

5S '

.......................................................-..

Stout, A. 1982. The Connecticut Hiv- salar). J. Fish. Res. Board Can. 0

er opportunity. Atl. Salmon J. 3-T-183.3(2): 16-17.

U.S. Fish and Wildlife Service. 1982.

Sweeney, R.K., and X.J. Huthertord The New England Atlantic salmon19b1. Evaluation of a freetall program: 1982, a year of firsts.apparatus for downstream passage NE Region 5. Fish and Wildi.

of Atlantic salmon (Salmo salar). Serv. U.S. Dep. of the In-Can. MS. Rep. Fish. Aquat.---ci . terior. 9 pp.No.(lb3Z): 7 pp.

Watt, W.D., C.D. Scott, and W.J.

Symons, P.E.K. 1979. Estimated White. 1983. Evidence of acidi-escapement of Atlantic salmon fication of some Nova Scotia(Salmo salar) for maximum smolt rivers and its impact on Atlantic •production in rivers of different salmon. Can. J. Fish. Aq. Sci.productivity. J. Fish. Res. Board 40:462-473.Can. 36:132-140.

Weaver, C.R. 1963. Influence of waterSymons, P.E.K., and M. Heland. 1978. velocity upon orientation ana

Stream habitats and behavioral performance of adult migratinginteractions of underyearling and salmonids. U.S. Fish Wildl.yearling Atlantic salmon (Salmo Serv. Fish. Bull. b3(1):97-121.

19

S ::: -

Peterson, R.H., and J.L. Metcalfe. Ritter, J.A. 1975. Relationships of1979. Responses ot Atlantic smolt size and age with age atsalmon, alevins to temperature first maturity in Atlanticgradients. Can. J. Lool. b7(7): salmon. Environment Canada,1424-143U. Fisheries and Marine Service.

Technical Report Series No.Peterson, R.H., H.C.E. Spinney, and A. MAR/T-75-5. 7 pp.

Sreedharan. 1977. Vevelopment otAtlantic salmon (Salmo salar) Rounsfell, G.A. 1957. Fecundity ofeggs and alevins under varied North Pmerican Salmonidae. U.S.temperature regimes. J. Fish. Fish. Wildl. Serv. Fish. Bull.Res. Board Can. 34(l):31-43. 122: 451-468.

Peterson, R.H., P.b. Daye, and J.L. Ruggles, 1980. A review of downstreamMetcalfe. 198U. Inhibition ot migration of Atlantic salmon.Atlantic salmon (Salmo salar) Can. Tech. Rep. Fish. Aq. Sci.hatching at low pH. Lan. J. No. 98b2. 39 pp.Fish. Aquat. Sci. 37:770-774.

Schaffer, W.M., and P.F. Elson. 197b.Pope, J.A., D.H. Mills, and W.M. The adaptive significance of var- 0

Shearer. 1961. The fecundity of iations in life history amongAtlantic salmon (Salmo salar L.). local populations of AtlanticDep. of Agric. of Fish. for Scot- salmon in North America. Ecolo-land. Freshw. Salmon Fish. Res. gy 56(3):577-9U.No. 26. 12 pp.

Scott, W.B., and E.J. Crossman. 1973.Power, G. 1969. The salmon of Ungava Freshwater fishes of Canada. A.

Bay. Arct. Inst. N. Am. Tech. Bull. Fish. Res. Board Can. 184.Rep. 22. 72 pp. 996 pp.

Pratt, V.S. 1946. The Atlantic sal- Shaw, H.M., R.L. Saunders, and H.C.mon in the Penobscot River. M.S. Hall. 197b. Environmental sali-Thesis. University of Maine at nity: its failure to influenceOrono. 86 pp. growth of Atlantic salmon (Salmo

salar) parr. J. Fish. Res. BoardRandall, R.G. 1982. Emergence, popu- Can. 32:1821-1824.

lation densities, and growth ofsalmon and trout in two New Siginevich, G.P. 1967. Nature of theBrunswick streams. Can. J. Zool. relationship between increase in6U(10):2239-2244. size of Baltic salmon fry and the S

outer temperature. idrob. Zh.Randall, R.G., and U. Paim. 1982. 3:43-38. Fish. Res. Board Can.

Growth, biomass, and production Transl. Ser. No. 9b2.of juvenile Atlantic salmon(Salmo salar L.) in two Miramichi Smith, G.W., A.D. Hawkins, G.G. Uro-Riv1-er, -NewBrunswick, tributary quahart, and W.M. Shearer. 198U.streams. Can. J. Zool. 60: 1647- The offshore movements of return- 01659. ing salmon. Salmon Net ?3:28-3Z.

Refstie, T., S.A. Torstein, and T. Stasko, A.B., A.M. Sutterlin, S.A.Gjedrem. 1977. Selection experi- Rommel, Jr., and P.F. Elson.ments with salmon. II. Propor- 1973. Migration-orientation oftion of Atlantic salmon smoltify- Atlantic salmon (Salmo salar).ing at one year of age. Aquacul- Int. Atl. Salmon Found. Spec.ture 10(3):231-242. Publ. Ser. 4. 4(l):119-138.

18

S ""

-- .t~z.-....•-...-..

alevins. J. Fish Biol. 19(3): (salmo salar L.) male smolts. 0353-360. Can. . Zool. 60:1822-1827.

Kazakov, R.V., and L.M. Khalyapina. McCrimmon, H.R. 1954. Stream studies1981. Oxygen consumption of on planted Atlantic salmon. J.adult Atlantic salmon, Salmo sa- Fish. Res. Board Can. 11:362-403.lar, males and temales in fisnculture. Aquaculture 25(2-3): McCrimmon, H.R., and B.L. Gots. 1979.289-292. World distribution of Atlantic

salmon. J. Fish. Res. Board Can.Kennedy, G.J.A., and C.U. Strange. 36:422-457.

1982. The distribution of sal-monids in upland streams in re- Meister, A.L. 1962. Atlantic salmonlation to depth and gradient. J. production in Cove Brook, Maine.Fish Biol. 20:579-b91. Trans. Am. Fish. Soc. 91:208-212.

Knight, A.E., and J.C. Greenwood. National Marine Fisheries Service1982. Special report - habitat (NMFS). 1983. Fisheries of the

criteria for Atlantic salmon and United States. 198?. Dep. Comm.,American shad. Pages DF1-DF16 Current Fisheries Statistics No.in Special report - anadromous 83U0. 117 pp. S

fish: water and land resourcesof the Merrimack River Basin. Netboy, A. 1974. The salmon: their

U.S. Fish and Wildlife Service, fight for survival. Houghton Mit-Laconia, N.H. flin Company, Boston, Mass. 594

PP.Knight, A.E., G. Marancik, and J.C.

Greenwood. 1981. Atlantic salmon Ottaway, E.M., and A. Clarke. 1981. Aproduction potential of the Mad preliminary investigation intoRiver, New Hampshire 1975-1980. the vulnerability of young troutUnpubl. Prog. Rep. U.S. Fish (Salmo trutta L.) and Atlanticand Wildlife Service, Laconia, salmon S. salar L.) to down-N .H. slo L

stream displacement by high watervelocities. J. Fish Biol. 19:

Leavitt, B. 1982. Mitchell targets: 135-145.woodcock, salmon. Bangor DailyNews. Fri. Aug. 13. 1982. Parrish, B.B. 1973. A review of the

work of the ICES/ICNAF jointLeim, A.H., and W.B. Scott. 1966. working party North Atlantic

Fishes of the Atlantic coast of salmon. Int. Atl. Sal. Found.Canada. Bull. Fish. Res. Board Spec. Pub. Ser. 4(1):383-39b.Can. 53. 485 pp.

Parry, G. 196U. The development otLundqvist, H. 1980. Influence of salinity tolerance in the salmon,

photoperiod on growth in Baltic Salmo salar L., and some relatedsalmon parr, Salmo salar, with species. J. Exp. Biol. 37:special reference to the effect 425-434.of precocious sexual maturation.Can. J. Zool. 58(5):940-944. Peterson, R.H. 1978. Physical

characteristics of AtlanticLundqvist, H., and G. Fridberg. 1982. salmon spawning gravel in some

Sexual maturation versus immatur- New Brunswick, Canada, streams.ity: different tactics with adap- Can. Fish. Mar. Serv. Tech. Rep. _tive values in Baltic salmon No. 785:1-28.

17

* . * * * . * * * . * . . . * *

. .. . . -,- -- , --',-. . . . . . . . . . . . . . . . . . . . . . . ..i I |. . .. . . ... .

Egglishaw, H.J., and P.E. Shackley. J. Fish. Res. Board Can. 23:1977-1977. Growth, survival and pro- 1980.

duction of juvenile salmon andtrout in a Scottish stream, Gibson, R.J., and M.H.A. Keenleyside.19bb-lb. J. Fish biol. 11:b47- 1966. Responses to light of

b7Z. young Atlantic salmon (Salmo sa-lar) and brook trout (Salvelinus

Elson, P.F. 197b. Atlantic salmon fontinalus). J. Fish. Res. Boardrivers smolt production and opti- Can. 23:1007-1024.

mal spawning: an overview of nat-ural production. Int. AtI. Sal- Gustafson-Marjanen, K.A. 1982. At-mon Found. Spec. Pub]. Ser. b. lantic salmon (Salmo salar L.)6:9b-119. fry emergence: success, timing,

distribution. M.S. Thesis.

Fisknes, B., and K.B. Doving. 1982. University of Maine at Urono.

Olfactory sensitivity to group 72 pp.

specific substances in Atlanticsalmon (Salmo salar L.). J. Chem. Haines, T.A. 1981. Acidic precipita-Ecol. 8(-T1T83TU2. tion and its consequences for aq-

uatic eccsystems: a review.FAO. 1981. 1980 yearbook of fishery Trans. Am. Fish. Soc. 11U(b):

statistics. Vol 50. Food and b69-7U7.Agriculture Organization of theUnited Nations Rome. 387 pp. Harris, G.S. 1973. Rearing smolts in

mountain lakes to supplement sal-

Francis, A.A. 1980. Densities of mon stocks. Int. Atl. Salmon -,'.**...- -

juvenile Atlantic salmon and Found. Spec. Pub). 4. 4(1):other species, and related data 237-252.from electroseining studies inthe Saint John River system, Havey, K.A., and K, Warner. 197U. The1968-78. Can. Data Rep. Fish. Aq. landlocked salmon (Saimo salar):Sci . No. 178: 95 pp. its life history and management

in Maine. Sport Fish. Inst., _

Fried, S.M., J.D. McCleave, and G.W. Washington, DSC. Fis9 pp.LaBar. 1978. Seaward migrationof hatchery-reared Atlantic sal- Huntsman, A.G. 1942. Ueath ot salmonmon, Salmo salar, smolts in the and trout with high temperature.Penobscot River Estuary, Maine: J. F Res. Board Can. b:4 b-riverine movements. J. Fish.Res. Board Can. 35:76-87.

5

Garside, E. 1973. Ultimate upper Hustins, U.G. 1981. The fight tor

lethal temperature of Atlantic survival of Salmo salar. Atl.salmon, Salmo salar. Can. J. Salmon J. 30(4):12-14.Zool. 5:8 --.

Jordan, R.M., ana K.F. deland. 1981.Gee, A.S., N.J. Milner, and R.J. Hems- Atlantic salmon spawning and S

worth. 1978. The production of evaluation of natural spawningjuvenile Atlantic salmon, Salmo success. Atlantic Sea-Run Salmonsalar in the upper Wye, Wales. Commission, Augusta, Maine. 2b7-Ts-h Biol. 13:439-451. pp.

Gibson, R.J. 1966. Some factors in- Kazakov, R.V. 1981. The effect offluencing the distribution of the size of Atlantic salmon, -brook trout and Atlantic salmon. Salmo salar, eggs on embryos and

16

9°'- "o .

I •I .,..

- - - - - . . .. . - - - . - .. - .. - -

LITERATURE CITED •

Allen, K.R. 1944. Studies on the Chadwick, E.M. 1982. Stock-recruit-biology of the early stages of ment relationship for Atlanticsalmon (Salmo salar): the smolt salmon (Salmo salar) in Newfound-migration in teThiurso River in land rivers. - an. J. Fish.1938. J. Anim. Ecol. 13:63-85. Aquat. Sci. 39:1496-1501.

Allen, K.R., and J.A. Ritter. 1977.Salmonid terminology. J. Cons. Clarke, L.A. 1981. Migration and or-Int. Explor. Mer 37(30):293-299. ientation of two stocks of Atlan-

tic salmon (Salmo salar L.)Allen, K.R., R.L. Saunders, and P.F. smolts. Ph.D. di-ssertation, Univ.

Elson. 1972. Marine growth of of New Brunswick, Fredericton,Atlantic salmon (Salmo salar) in N.B. Canada.

the Northwest Atlantic. J. Fish.Res. Board Can. 29(10):1373- Daye, P., and E. Garside. 1977.1380. Lower lethal levels ot pH for

embryos and alevins of AtlanticBaum, E.T., and A.L. Meister. 1971. salmon, Salmo salar L. Lan. J. S

Fecundity of Atlantic salmon Zool. b5:15U4-1bO8.

(Salmo salar) from two Mainerivers. " .- i-h. Res. Board Can. "-.--rivers. T s ResBoarCan. Daye, P., and E. Garside. 198U. Ue-

28:764-767. velopment, survival, and struc-Beland, K.F., R.M. Jordan, and A.L. tural alterations of embryos ana

r ad Aalevins of Atlantic salmon, Salmo OPPMeister. 1982. Water depth and salar L., continuously exposed tovelocity preferences of spawning alkaline levels of pH from terti-Atlantic salmon in Maine rivers. lization. Can. J. Zoo]. bb(3): -.-

N. Am. J. Fish. Manage. 2(l):11- 369-37713.

Bigelow, H.B., and W.C. Schroeder. DeCola, J.N. 1970. Water quality re-13 Fquirements for Atlantic salmon,

1953. Fishes of the Gulf of USDI. Federal Water Quality Ad-Mine BuS. Fish4:1id7. Servministration, N.E., Region, Bos-Fish. Bull. 53(74):1-577.toMs.4p.• " ton, Mass. 42 pp.

Brawn, V.M. 1979. Efficiency of anestuarine fishway for the passage DeCola, J.N. 197b. Atlantic salmonof salmon (iSalmo salar L.) Sheet restoration and the question ofHarbor, Nova Scotia. Fish. Envir- water quality. Int. Atl. Salmonon. Can. Fish. Mar. Ser. MS. Rep. Found. Spec. Pub]. Ser. b:?4-28.1523. 9 pp.

Dunbar, M.J. 1973. On the WestBrewster, W.S. 1982. Are the Faroese Greenland sea life area of the

ruining the salmon fishing? Atl. Atlantic salmon. Arctic Z6(1):Salmon J. 30(3):8-11. 3-6.

15

. . . . . . . . . . . . . ..*.%.%**.,...-.. .

survival of salmon by preventing solarA oradiation from warming the water above ...... 7.Pthe upper lethal temperature (McCrim-mon 1954). 2

alevir , --n".

Salinity - r, /030 -40 m~m 2 ;

Tolerance of Atlantic salmon to i vsudden changes in salinity differs I I

among its life stages (Parry 1960). 6wks_ _ _ 0Smolts greater than 120 mm can survive 100 70 o M5 0 (%)an instantaneous change from fresh- 30 Is (Ptqwater (0.1 ppt) to 100% seawater (30 Sea water "P-

ppt) for 84 hr, and are completelytolerant when introduced into 27 ppt Figure 7. Survival time of aifferentseawater. Parr 7 to 100 mm can toler- life stages of Atlantic salmon in var-ate 30 ppt seawater for 10 hr after ious seawater concentrations (Parrydirect introduction, and survive in- 1960).definitely in waters of 22 ppt. Parr .630 - 40 mm are able to survive foronly 2.5 hr in 30 ppt seawater but are Substrate, Sediment. and Turbiditytolerant of about 18 ppt seawater.Fry 15 - 20 mm perish within 2 hr The spawning habitat has a parti-after sudden introduction into 30 ppt cle size composition consisting ofseawater but can tolerate a level of 8 0%-3% fine sand (0.06-0.50 am); 10%-ppt indefinitely. Six-week-old ale- 15% coarse sand (0.5-2.2 mm); 40%-50%vins survive for only 0.5 hr in 30 ppt pebble (2.2-22 mm); and 4U%-bU% cobbleseawater but survive well at salin- (22-256 mm) (Peterson 1978). Firstities near 20 ppt. One-week-old ale- year fish (0+) prefer a substrate otvins, however, are able to survive up gravel 1.6-6.4 cm in diameter whileto 9 hr in 100% sea water, even parr of age 1+ prefer a boulder andthough 3% is optimal. Parry (1960) rubble substrate greater than Z6 cm insuggests that the epithelium of these diameter (Symons and Heland 1978).alevins is able to maintain some de- Bottom sedimentation plays an import-gree of impermeability, which is lack- ant role in the survival and distribu-ing in somewhat older fish, and may tion of juvenile salmon (McCrimmonaccount for the longer survival of 1954). Spaces between pebbles andyounger fish at high salinities (Fig- cobble are used as shelter by try andure 7). parr. Deposition of sediments that

clog these spaces decrease survival ofAtlantic salmon parr, though salmon fry and parr (McCrimmon 19b4).

adapted for life in freshwater, can Turbidities in excess of 11bU standardreadily survive within a wide salinity units, caused by autumn treshets, didgradient from 0 to 20 ppt (Shaw et al. not injure or kill salmon try and1975). Instantaneous growth rates and parr. McCrimmon (19b4) suggested thatfood conversion efficiencies of salmon turbid water in spring may protect mi-in different salinities were similar. grating smolts from predation.

14

-S -.

0

lethal pH for embryos is about 3.5 mm long tend to stay in depths less 0

during early cleavage and about 3.1 than 20 cm (Kennedy and Strange l962).just before hatching. The try may not be able to compete

with older parr in deeper waters be-Death by low pH is attributed to cause of predation and/or chasing, or

dysfunction of ionregulation, asphyx- they may simply prefer shallower wa-iation, and elevation of metal concen- ter. Competition for space among fishtrations. Exposure to low pH causes of different ages may be the criticaledema between outer gill lamellar regulating factor affecting the sur-cells and other gill tissue, disrupt- vival of first-year (U+) try. In oneing respiration and excretion. A pH study (Knight et al. 1981), the pre-of 5.0 or lower affects eggs by de- ferred fry habitat had a mean depth otgradation of the enzymes responsible 25 cm (range 9-39 cm). The depth otfor movement of the embryo within the 62 sites where salmon fry were round -egg, without which hatching is impos- in New Brunswick streams ranged fromsible (Haines 1981). At pH 5.0-5.5 10 to 31 cm (Francis 198U).reproduction fails. Alevins subjectedto low pH at 7 days and parr at 28 Parr, I+ year and older, seem todays after hatching had a lower lethal prefer waters 1U-4U cm deep. Meanlimit of about 4.0 (Daye and Garside depth of preferred areas in New Eng-1977; 1980). Rivers in Nova Scotia land streams was 29 cm (Knight et al.with a mean pH less than 4.7 have lost 1981), and 1U-15 cm in Canadiansalmon runs; between 4.7 and 5.0 runs streams (Symons and Heland 1978).declined; and above 5.0 runs were un-affected (Watt et al. 1983). First-year fish (age U+) preterJuveniles in these Nova Scotia streams water velocities of bU-b5 cm/sec (Sym- -

were most numerous at mean annual pH ons and Heland 1978). Knight et al.above 5.4, much reduced between 4.7 (1981) reported that preferred habitat - -

and 5.0, and absent below 4.7. of 0+ fish had a mean velocity of 14cm/sec (range 1.8-32 cm/sec), whereas

Depth and Velocity 1+ parr were in habitat with a meanvelocity of 20 cm/sec (range 14-32).

The optimum stream habitat for Stream gradients that salmon preferspawning is a gravel tail of a pool range from 2 to 12 m/km (Elson 197b).with a hydraulic head produced by ariffle or a steeper gradient below the Resting pools for upstream mi-pool. The gravel has an average area grants are important as temporary re-of 3.8 m 2 . fuge from swift currents. Large boul-

ders and other stream obstructionsWater depth over a redd averages provide eddies and slack water in

0.4 m in Maine rivers (Beland et al. which adult salmon may rest. 0

1982) and 0.2 m in New Brunswick riv-ers (Peterson 1978). Water velocity Lightat 12 cm above the substrate averaged49 cm/sec in Maine, and at 2.5 cm At surface illuminations betweenabove the substrate, 52 cm/sec in New U.4 and 160 foot-candles (fc), salmonBrunswick (Elson 1975). The average were photopositive, while at illumin-water depth in a Maine salmon stream ations above 3UU tc they were photo-was 38 cm (range 17-76 cm) with a negative when the lighted area had anwater velocity of 53 cm/sec, measured unbroken substrate (6ibson and Keen-12 cm above the substrate (Beland et leyside 1966). With submerged coveral. 1982). in the lighted area, the salmon were

photopositive. The amount of shadeAtlantic salmon fry less than 60 over a stream indirectly aftects the O

13

-x -. *-- - - - - - . - - - ----

predaceous fishes; gulls, mergansers, tures higher than 28C. Temperaturescormorants, herons and kingfishers; of 200 -270C reduce resistance to dis-and backswimmers and leeches. At sea ease and are therefore indirectlymajor predators are pollock, tuna, lethal. At water temperatures aboveswordfish, sharks, otters, and seals. 20% adults are rarely caught by ang-

ling.

ENVIRONMENTAL REQUIREMENTS Dissolved Oxygen 0

Temperature For optimum growth and develop-ment, dissolved oxygen concentrations

Water temperature is the key fac- should be at or near saturation; goodtor in the delineation of the geo- development requires at least b mg/lgraphical range of the Atlantic sal- (Elson 1975). Streams with dissolvedmon. They require cool temperatures oxygen concentrations below b mg/l areat all stages of their life history. not usually inhabited by salmon. Mi-Spawning occurs between 4.4°-10'C. grating adult salmon require a minimumThe optimum temperature of egg ferti- of 5 mg/l for exposure less than b hrlization and incubation is about 6C, and 6 mg/l for exposure more than b hralthough development may occur at (DeCola 19701.slower rates at temperatures as low as0.5°C (Peterson et al. 1977). Tem- The respiration of adult Atlan-peratures of 7% are tolerated, where- tic salmon is depressed at oxygenas temperatures above 12% increase concentrations below 4.b-b.U mg/legg mortality. Temperatures between (Kazakov and Khalyapina 1981I). At8' and 12% may indirectly increase concentrations from 1.b-1.7 mg/l, mostmortality, due to a higher incidence fish die from a lack of oxygen. Le-of fungal infection (Garside 1973; thal concentrations for juvenile At- .* - SDeCola 1975). Newly hatched Atlantic lantic salmon are about 1.1 mg/l torsalmon alevins select the lowest age 0+ parr and 2.3 mg/l for age 1+temperatures available. About 250 parr tested at the same water temper-degree days after hatching the alevins atures as the adults. Embryos requireselect a temperature of 14% (Peterson even higher oxygen levels of b-7 mg/land Metcalfe 1979). (DeCola 191U). Oxygen consumption 41-

differs among fish of different sex, 0Growth and production of juven- age, and weight. The rate of oxygen

iles are optimum at water temperatures consumption in adults decreases withof 150-19°C (DeCola 1970), although age and body weight.they will tolerate temperatures up to27°C, at which point they move to plcolder water. Huntsman (1942) statedthat salmon could withstand temper- Fluctuations in pH of water are 0atures of 32C for brief periods. The important in the freshwater en-lethal temperature for juveniles is vironment of the Atlantic salmonabout 32°C (Garside 1973). Power (Peterson et al. 198U). Tolerance to(1969) suggested that a minimum of 100 low pH varies among different litedays in which the temperature exceeds stages and ages. High mortality ot6C is needed for the growing season. eggs and alevin has been attributed to 0Siginevich (1967) reported that growth low pH, which is chacteristic ofwas optimum at 16.6°C. snowmelt and heavy fall rains. Lggs

develop normally at pH b.b-b.8. A pHAdults grow in ocean temperatures of 4.0-5.5 delays or prevents hatch-

as low as 2C (DeCola 1975). Mortal- ing, yet returning these eggs to pHity can be expected at water tempera- 6.6 induces hatching. The lower

12

-0..

3000- "total catch ticut River (down trom the b3U in 0EOGreenland' 1981) and 36 (an estimate ot bU) in2500 - 6 Den mnark.,N orwtay, Sweden ; .i ,

2500 - e.Faroe en the Pawcatuck River in Rhode Island,r the first time adult Atlantic salmonS2000- have returned to this river in nearly

1500 200 years.

1000 4 As a sport fish, Atlantic salmon 0are rated as one of the best. They

500 6are hard fighters and high jumpers and

are considered a prestigous game tish196M).i '62'63 6465 '66'6768 'g'7 by many anglers. In 1982, Penobscot

Year anglers reported catching 914 salmon* set gill-net and drift-net (about 1500 were actually caught) dur-

** drift net catch ing 13,384 angler days on one short

Figure 6. Greenland and Scandanavian section of 115 acres of the river.

catch of Atlantic salmon from 1960 The average angler tished 38 hr to

to 1971 (Dunbar 1973). catch one fish (U.S. Fish and WildliteService 1982).

ECOLOGICAL ROLE

Food Habits

trend of increased catches on the high Young Atlantic salmon usuallyseas (Figure 6), quotas were set remain relatively stationary in the(Brewster 1982; Leavitt 1982). The stream and feed on invertebrate drift.Faroe Island fishery quota was set at Their diet consists chiefly of larvae750 metric tons in 1982, and 625 met- of mayflies and stoneflies, chirono-ric tons in 1983. The quota for Green- mids, caddisflies and blackflies, aq-land was set at 1,250 metric tons for uatic annelids and mollusks. Largerthese years. The Convention for the juveniles feed on aquatic insects andConservation of Salmon in the North terrestrial insects that fall into theAtlantic Ocean Treaty, approved Feb- water (Scott and Crossman 1973).ruary 1982, prohibited salmon fishingwithin 12 mi of another country's In the sea, smolt and larger sal-coastline, with the exception of West mon eat herring, lance, alewives, cap-Greenland, where fishing only beyond elin, smelt, small mackerel, cod,40 mi was permitted, and the Faroe haddock, and crustaceans (Leim andIslands where fishing was permitted Scott 1966; Scott and Crossman 1973).only beyond 200 mi. Salmon eat very little or nothing

after returning to freshwater from theBased on catch by anglers and in sea, but some will attack an angler's

traps for hatcheries the total return lure.in Maine in 1982 was 4,685 adult At-lantic salmon, compared to 4,134 in Predation1981 (U.S. Fish and Wildlife Service1982). Records are incomplete, how- Salmon are eaten by a variety of 0ever, for some of the smaller rivers, predators in freshwater and at seaOf the 1982 run, 4,161 were from the (Leim and Scott 1966; Scott and Cross-Penobscot River. In southern New man 1973; Harris 1973). Young salmonEngland in 1982, 46 salmon returned to are eaten by eels, northern pike,the Merrimack River, 70 to the Connec- brook trout, larger salmon, and other

%0-'.': Ii.... . . . . . . . ....

- --.-. .

Table 2. Landings (lb) and values salmon has been reported for Massachu- -

(U.S.$) of commercial catches of setts and Maine, where sale of salmon .0

Atlantic salmon in Massachusetts and caught with sport year is permittedMaine in 1964-1978 (from annual issues (Table 2). Sport catches provide aof Current Fishery Statistics, NMFS better measure of the Atlantic salmon1983). fishery (Table 3).

Collapse of the Lake Untario 0Massachusetts Maine Atlantic salmon fishery prompted a

series of legislative acts in Canada,Year Landings value Landings value to control the commercial fisheries.1964 - - 454 385 A 1973 ban on drift-net fishing off1965 8 7 208 161 Newfoundland and on commercial fishing1966 12 10 292 236 in New Brunswick (both lifted in 1981)1967 - - 232 211 was a response to world reductions ot 1968 - - 61 61 Atlantic salmon catch (Hustins 1981).1969 - - 18 181970 11 10 182 182 In the jate 196U's and early1971 - - - - 1970's, tagged salmon from both sides1972 - - 100 100 of the Atlantic were caught in a com-1973 25 25 63 69 mon area off the west coast of (reen-1974 35 39 68 84 land and off the Faroe Islands (Par- ..

1975 - - 269 342 rish 1973). Because Atlantic salmon1976 8 14 43 69 swim close to the surface, they are1977 - - 70 100 easy to catch in drift and set gill1978 5 10 474 1115 nets (Dunbar 1973). To reverse the

' -

Table 3. The sport catch of anadromous Atlantic salmon in New England rivers, U(Norman R. Dube, Maine Atlantic Salmon Commission, personal comnunication;Lawrence A. Bandolin, U.S. Fish and Wildlife Service, personal communication).

Number of fish caught

River 1978 1979 1980 1981 I82 183".

Penobscot 360 136 837 72b 91b lbb 0

Narraguagus 135 58* 119 78 8b byMachias lob 65+ 80 53 59 '5Dennys 75 38+ 190 129 4U V7East Machias 60 25 62 8b 33 8Pleasant 16 7 5 23 19 -Sheepscot 35 5+ 30 15 12 1UUnion 10 3+ 29 32 1U bMerrimack 1 2 2 2 12 23Connecticut 0 2 4 13 2 b**Others*** - - 20+ - 12• through September 11, 1983•* estimated*** includes Kennebec, Ducktrap, St. Croix, Androscoggin, and Saco Rivers. _

10

- € . .. . .... % . . . . . . . . ..-....7'.-' '-° . . . .

. ..- . O o .

in freshwater and the ocean can be COMMERCIAL/SPORT FISHERIES 0estimated. During upstream migration, A n s n r l hthe salmon partially absorbs its e tmbthe Ran and hld heyscales; thus, the number of spawningruns made by an older fish can also be were an important commercial fish indetermined (Pratt 1946). the British Isles and medieval Europe.

They were mentioned in the Magna Car-

Production (P) of juvenile Atlan- ta and were an important source of 0

tic salmon can be estimated from the protein in the American colonies.

mean biomass (B) for all year-classes Settlers found rivers teeming with

present in a typical Welsh stream (Gee them. Reports of their capture withet al. 1978) with the following for- pitchforks and their use as fertilizermula: were documented by Stout (1982). In

the late 1800's dams and water pollu-tion destroyed the Atlantic salmon in

P =-2.5 B0 .91 U.S. waters except for a few streamsin Maine. Populations in some Canadi-an streams were diminished by 18bU.At this time Maine had the only re-

The exponent actually ranged from 0.73 maining profitable commercial Atlanticto 1.24, and the coefficient ranged salmon fishery in the United States.from -1.91 to -3.05. The higher About 70% of the catch was from thevalues appeared in the spring and Penobscot River, but by 189b, only 4Usummer. fish were landed there. Since then,

the United States has had no signiti-According to Egglishaw and Shack- cant commercial catch of salmon (Table

ley (1977) the size of 0+ salmon in a 1). This is a biased value since com-Scottish river depended on the growing merical fishing is illegal in the .season's length, which is determined United States. A small catch otby emergence time, degree days aboveOC, and population density(numbers/m 2). The relationship offork length (FL) to population density(N) and degree days (0) is determined Table 1. Commercial catches of At-by the following equation: lantic salmon in metric tons ot the

major Atlantic fisheries 1977-198U(Food and Agricultural Oryaniza-

FL = 17.152 - 2.80DN + O.0194D tion 1981).

Country 1977 1978 1979 IYU.No significant relationship between Canada 2,134 1,32U I,u84 2,378length of 1+ salmon and their popula- Greenland 2,72b 2,163 2,467 2,u8Ytion density could be established. Denmark 1,214 9bU I,U4Y 1,133Egglishaw and Shackley determined that Ireland 1,184 817 I,b28 1,bblthe annual production rates for salmon U.S.S.R. 344 17u b3U 96branged from 5.5 g/m2 to 12.1 g/m2 and Scotland 4bU 472 318 Bb

averaged 8.9 g/m2. Production in the Finland 782 5bb b84 b7

second year of a particular year class Sweden 619 b14 b7U bU2could not be statistically related to Faroe Is. 40 37 - b33production of that year class in its Iceland 23U 291 22b ?48first year of life. Symons (1979) N. Ireland 111 IbU 99 122reviewed several studies and noted Norway 80 87 8b 7Uthat smolt production in streams France U 2 3 23ranged from about I to 10 smolts/100 Germany FR 6 8 b b

02. U.S.A. <1 <1 <1 <1A_.__ _ _

o - . " o . "9

first time later than those that smol-

140 smolt tify in 2 or 3 years (Ritter 197b). -E The mean age of the female's firstE spawning varies over the salmon's

100 range in North America, decreasing

a from Maine to Ungava (Schaffer and* Elson 1975). The mean age of first

60.. spawning among individuals iso positively correlated with growth

rates at sea.20

2 3 Growth in the sea is faster thanYear in stream in freshwater (Figures 4 and b). In I

year at sea a salmon may grow 1-3 kgFigure 4. Growth of Atlantic salmon and in 2 years, 3-7 kg. Average Sin freshwater (McCrimmon 1954). weights of anadromous salmon returning

to various streams range from 2 and 9kg although weights have been recordedup to 38 kg. Commercially caughtsalmon average 4.b kg. Adult land-locked salmon average 1-2 kg (Scott

Chadwick (1982) warned that the and Crossman 1973). •2.4 eggs/m' often cited by managementbiologists as optimum, may be an The growth of Atlantic salmon is"arbitrary" figure and that optimal reflected in scales. When about 3U mmegg deposition could be considerably long, the fry begin to grow scales,higher in productive salmon rivers, first along the lateral line at the _.- _-.--"-

Symons (1979) calculated ideal numbers centrdl and posterior parts of theof eggs needed in streams of differing body. During rapid growth, broadsurvival and adult escapement, ranging bands form on the scale, similar tofrom 23 eggs/m 2 with low escapement growth rings on a tree. These bandsand high survival to 591 eggs/m under are used to determine the age andhigh escapement and low survival, growth of individuals. Because growth

differs in freshwater and the ocean, LLundqvist (1980) reported that the time that an individual has spent

photoperiod also influences growth.Sexually immature male and female At-lantic salmon exposed to a light:dark 1000(LD) ratio of 20:4 grew faster thanthose exposed to a natural photoperiod oo

(nLD) or LD 6:18. Sexually maturing E "o .-

male parr, however, grew slower in LD J 60020:4 than did immature fish exposed tothe same photoperiod. When exposed to ; 400LD 6:18 or nLD, maturing males ripenedearlier. 200 l'/ ':".oo o. oooo •

Size is one of the most important 0factors determining the age at which 2 3 4Atlantic salmon become smolts (Refstie Year in seaet al. 1977). Fish that become smolts Figure 5. Growth of Atlantic salmon atin one year mature and spawn for the sea (Allen et al. 1972).

8

• ,7- ,

After feeding at sea, most Atlan- after spawning. Many spent fishtic salmon return to their natal .?lts) survive the winter in fresh- 0stream to spawn. Return to the home water and resume feeding. Apparentlystream may be aided by detection of mortality is high when the kelts enter

olfactory stimuli from the stream that saltwater. Fish that survive and mi-initiate behavioral response mediated grate to oceanic feeding ground mayby memory of the home stream odor become repeat spawners. Landlocked or(Stasko et al. 1973). One hypothesis permanently freshwater salmon movefor homeward navigation is that during from the lake where they feed to athe downstream migration, smolts re- tributary stream where they spawnlease a pheromone, creating an odor (Havey and Warner 197U).trail specific for each populationfrom the home stream to the feedingground (Fisknes and Doving 1982). GROWTH CHARACTERISTICSAdults may follow this trail to return S

to their home stream. Growth of the Atlantic salmon isinfluenced by both genetic and envir-

Some adults (grilse) return to onmental factors. Embryo size andtheir home stream after I year at sea, weight are determined by egg size,weighing 1-3 kg. Other adults (bright which is influenced by the age, sizesalmon) return after 2 or 3 years at and physiological condition of the fe-sea and weigh 3-9 kg, although much male. Egg diameter increases with thelarger salmon have been recorded age of the fish and the length of time(Scott and Crossman 1973). Fish re- the fish spend in ocean feeding. Eggturning to Maine rivers usually have size also varies in individual fe-spent 2 years at sea (Beland et al. males, depending on the position of .1982). At sea the returning adults the eggs in the ovary (Kazakov 1981).

swim at rates of 0.08-0.68 n/sec(Smith et al. 1980). Growth of try and parr in fresh-

water is relatively slow (Figure 4).Salmon congregate in estuaries, Salmon fry obtain maximum growth in

bays, and river mouths before migrat- July with little or no growth after

ing upstream. Migration often coin- September (Randall and Paim 1982). Itcides with freshets or other sustained may take 2-3 years to reach a I2b-lbUincreases in water flow. Freshets are mm fork length in streams in New Lng- 0less important in spring when water is. land, and 4-8 years to reach IU mm incolder and the flow higher than in Ungava Bay (Schaffer and Elson 197b).summer or in autumn (Brawn 1979). In productive streams in Maine 1+ parrSalmon are rheotactic and require a may reach 150-17b mm, and 2+ parr ofminimum stream velocity of 0.3-0.6 21U mm are occasionally seen.m/sec to continue movement upstream(Weaver 1963). Stasko et al. (1973) Normal growth of parr occurs at 0reported that the rate of progress water temperatures of ib'-19'C (Knightupstream against an average flow and Greenwood 1981). Populationvelocity of 0.5 m/sec (35 km/day) was density also affects growth and4.3 km/day. survival. Growth rates are usually

greater where densities are leastAdult salmon do not feed in (Randall 1982). From a study on the

freshwater. As males mature, their Pollett River, New Brunswick, Llsonheads become elongate and the lower (197b) concluded that average smoltjaws become enlarged and hooked, form- production in an ideal salmon streaming kypes. The females choose the should not exceed six smolts/1iUUm2.spawning site. In contrast to Pacific This calculation was based on asalmon, Atlantic salmon do not die spawning intensity of 170 eggs/100 M2

7

i...... ....... ....... ...... . . ...

prevented from seaward migration they stream; but in swift currents, they 0again become parr and lose their abil- orient upstream. Migrating smoltsity to survive in salt water (Lund- passively drift in the main current ofqvist and Fridberg 1982). the stream away from the shoreline.

On reaching the estuary, smolts swimSmolts and Sea Migrants seaward during the flood tide. Im-

poundments delay or restrict migra-The smolt is the next stage in tion. Fried et al. (197b) tound that

the life history of the Atlantic sal- the entire journey from freshwater tomon. In Maine, about 80% of the juve- seawater took less than 48 hr over aniles spend 2 years in freshwater and distance of 57 km. Smolt movement in20% spend 3 years. According to Elson estuaries is dependent on the charac-(1975) 38% of the parr in the Polett teristics of the estuary (ClarkeRiver, New Brunswick survived to 1981). Stock-specitic sun compasssmoltification (survival from egg to orientation and tidal transport aresmolt was 1.1%). Chadwick (1982) re- responsible for smolt movement out ofported 3.6% and 3.2% survival from egg an estuary. Movement in deep water isto smolt in two Newfoundland streams. parallel to current direction, whileMeister (1962) observed survival of b% in shallow water sun compass orienta-from fry to the smolt in Cove Brook, tion is dominant (Clarke 1981).Maine. Symons (1979) analyzed egg-to-smolt survival in the Miramichi River, Mortality due to freefall overNew Brunswick, and concluded that per- dams and natural falls is likely itcentage survival was inversely related the velocity of the fish exceeds lbto the initial number of eggs depos- m/sec on impact with the water. lhisited. Absolute numbers of smolts pro- velocity is reached by smolts fallingduced, of course, was higher in a vertical distance of 27 m wherestreams receiving heavy egg deposi- discharge is U.4 m3/sec (grilse, 18 m, 0tion, up to about 300 eggs/100 m2 , and kelts, lb m) according to Sweeneyabove which density-dependent mortal- and Rutherford (1981). Ruggles (198U)ity compensated for increased numbers. cited that smolts may withstand free

fall of up to 90 m.After the parr reach 125 to 150

mm, the parr marks disappear anddeposition of guanine in the skin Sea Life and Homeward Migrationcreates a silvery pigmentation. Thetail lengthens and becomes more deeply Once in the sea, Atlantic salmonforked. Schooling behavior replaces travel to distant feeding groundsterritorial behavior. (Netboy 1974). Most American and

southern European salmon migrate toDuring the spring, rises in water the Davis Straits between Labrador and

levels due to freshets and water tem- Greenland (Figure 2). Salmon from theperature increases +4.5 to +5.50 C Baltic Sea and British Isles migrateinduce downstream smolt migration in to the coast of the Faroe Islands.the Thurso River, Scotland (Allen The postsmolts swim within 3 m of the1944). Fried et al. (1978) reported ocean surface at a rate of up to bW.that a rise in temperature to 5°C km/day. One possible explanation fortriggered downstream migration in the their navigating such long distancesPenobscot River, Maine. Smolts ex- on target is their ability to detectpressed full migratory behavior at changes in earth's electromagnetic9°-100 C. Peak movements were at dawn geoelectric fields caused by theand dusk. In riffles and low-velocity passage of ocean currents through thestream sections, smolts orient down fields (Stasko et al. 1973).

6

..- o .° .-.

S0272-101

REPORT DOCUMENTATION 1. REPORT NO. ig j t4

R ciP~ents Accesson No. "

PAGE _ FWS/OBS82/11.22*4. Title and Subtitle 5. Report DateSpecies Profiles: Life Histories and Environmental Requirements July 1984of Coastal Fishes and Invertebrates (No"th Atlantic) -- Atlantic .-Salmon ___-"

7. Author(s) i. Performing Organization Rapt. No

Dwight S. Danie, Joan G. Trial, and Jon G. Stanley - .

9. Performn g Organization Name and Address . " . 10. Proect/Task/Wok UnitNo

Maine Cooperative Fishery Research Unit313 Murray Hall, University of Maine 11. Contract(C) or Grant(GI No.

Orono, ME 04469 (C)(G)

12. Sponsoring Organization Name and Address 13. Type of Report Period Covered

National' Coastal Ecosystems Team U.S. Army Corps of EngineersFish and Wildlife Service Waterways Experiment StationU.S. Dept. of the Interior P.O. Box 631 34._

Washington, DC 20240 Vicksburq, MS 3918015. Supplementary Notes

* *U.S. Army Corps of Engineers Report No. TR EL-82-4

16. Abstract (Limit: 200 words)

Species profiles are literature summaries on the taxonomy, morphology, range, life historyand environmental requirements of coastal aquatic species. They are intended to assist inenvironmental impact assessment. Atlantic salmon are a highly prized sport fish and theirflesh is gourmet table fare. Once abundant inNewEngland's coastal rivers, they are only nowbeing restored to portions of their original habitat. Populations declined following deve-lopment of industries along rivers and commercial fisheries in estuaries. Atlantic salmonare anadromous. Spawning, embryo development and growth of young fish occur in freshwaterstreams and rivers. Juvenile survival is highest in clear, cool (<27°C), well oxygenated(dissolved oxygen > 5 mg/l) streams. Following smoltification, a physiological changeenabling entry into salt water, fish migrate downstream and then to oceanic feeding groundsnear Greenland, where they grow rapidly. Sexually mature fish return to their natal rivers ospawn. Migration into estuaries and lower reaches of rivers begins 7 months before theOctober-November spawning period. Migrating adults require dissolved oxygen concentratiunsgreater than 6 mg/l for successful upstream movement. Because juveniles migrate throughthe coastal zone in spring and adults in summer and fall the species is especially vulnerab.to the consequences of coastal development. ,.

17. Document Analysis a. Descriptors

SalmonFishesRiversMii gration

* b. Identiftersf/Ocen-Ended Term s

*Atlantic salmon Habitat requirements. Salmo salar Spawning

" Temperature requirements Life history

C. COS&TI Fseld/Goup

18. Availabity Statement Di~fB rMON STATEMFNT A 19 Secu' :y Class In. Report 21. No ....

Unlimited Unclassified 19,'.",.. Un limited | p mo O . ... y .. ... " "

IApptOYed im public ?e?*Qa" 20. SecurlIy Class (1, Pagel 22. '

,eASZ.8 J Distribution Utdimite4 UnclassifiediD(See ANSI-Z9))- OP~TIONAL FORWL. ?,; -

Det-'.

........ ..................................................... ..... i

~4Headquarters. Divisionl of BiologicalServices, Wasngton. DC A

Sn Eastern Energy and Land Use Team at r r. x-O-anLeetown. WV Vri sad

0National Coastal Ecosystems TeamSlidell, LA

0Western Energy and Land Use Team

I * * Locations of Regional Offices

REGION I REGION 2 REGION 3Regional Director Regional Director Regional DirectorU.S. Fish and Wildlife Service U.S. Fish and Wildlife Service U.S. Fish and Wildlife ServiceLloyd Five Hundred Building, Suite 1692 P.O. Box 1306 Federal Building, Fort Snelling500 N.E. Multnomah Street Albuquerque, New Mexico 87103 Twin Cities, Minnesota 55111Portland, Oregon 97232

*REGION 4 REGION 5 REGION 6Regional Director Regional Director Regional DirectorU.S. Fish and Wildlife Service U.S. Fish and Wildlife Service U.S. Fish and Wildlife ServiceRichard B. Russell Building One Gateway Center P.O. Box 2548675 Spring Street, S.W. Newton Corner, Massachusetts 02158 Denver Federal CenterAtlanta, Georgia 30303 Denver, Colorado 80225

REGION 7Regional DirectorU.S. Fish and Wildlife Service

-~1 l1l F. Tudor RoadAnchorage, Alaska 99503

%*0

*.FILMED.

44-85

DTIC