UNITED STATES DEPARTMENT OF THE INTERIOR , St wart dall, Secretory James K. Carr, Under Secretory Frank P. Briggs, Assistant Secretory for F ish and Wildl ife FISH AND WILDLIFE SERVICE, Clarence F . Pautzke, Comml ssioner
BUREAU OF COMMERCIAL FISHERIES, Donald L. McKernan, Director
Fishery leaflet 555
Washington, D.C. 20240 February 1964
THE LAKE TROUT (Salvelinus namaycush)
b y Paul H . Eschmeyer
The lake trout (al so called mackinaw, it resembles more closely t han other trouts, togue, gray trout, Great Lake s trout, or by it s deeply forked tail, by the abs nc of n amaycushl is a member of the salmon brightly colored spot s on the body, and by fam'ly (Salmonidael. Its body form, although the a b sence of conspicuous light dgmgs on variable, is usually moderately elongate and the lower fins. typical of the form shared by other trout and salmon. The scale s are small, and the A number of different races or subpopu head, eyes, and mouth are large. The jaws, lations of lake trout occur withIn Its g 0- tongue, and roof of the mouth are strongly graphic range . The species has Its great st toothed. The conspicuous dorsal fin usually diver sif ication in Lake Superior, wh r as has 11 rays; a small fatty fin is located many as a dozen subpopulations are bell ved on the b ack near the tail. All fins are with to occur. Although fish of the dIffer n out spines; they are grayish, although the races often are not recognizabl by ext rn I lower fins may show varying amounts of character s , their Identity is perpetuat d by orange. distinctive differences in localIty, d pth, The body color of the lake trout var ie s and/ or date of spawnmg. One of th Ldk widely; shades of gray and olive predomi Superior forms is the siscowet, or fat lak nate. Much of the body is mottled with light trout, which is commonly g 1 V n sub gray or whitish s pots, and vermiform trac specif ic ranlung (Sal1H'linU8 namay('u.~/, Ulr ou el). ings cover the head and back. The species As adults , most slscowets are extr mely is distinguished from the brook trout, which fat, deep-bodied fish that live at d pths greater than 300 fe et. The fat or oil conten 5 Note. - - Paul H.. Eschmeyer, Assis lant Laboralary D&re Clar, of the flesh o f large specimens rang up Bureau or Commercial Fisheries G r ea t Lakes Research, to nearly 70 per cent- - pe rhap highe r han Ann Arbor, Mich. in any other f ish in he world . The co or of he fle h of lake rout may Lake Superior may spend their entire life rein e from whlte to deep reddish orange in water at a much lowe r temperature, among f l h ai Spawning seasons and grounds.- - Lake GEOGRAPHIC DISTRIBUTION trout spawn once a year, usually in late summer or fall. The date depends on a The lake t rout IS pr Incipally an inhabitant variety of f actors, which apparently include of 1 .rge, cool freshwater lakes o f northern physiological d iff ere n c e s among race s, . )r \-1 AmerIca . Its range extends from physical characteristic s of the lake, lati Al i,;ka eastward to the Labrador Peninsula. tude, weather conditions, and water tem .,) • to northern! ew England, and west peratures. Most spawning is in October, but t • rl 19'1 ,'ew York, the Great Lakes drainage the breeding season begins in August in the bd S In, the nor t hern margin of the Missis sippi northern part of the range and extends into liver watershed In Wisconsin and Minne November in the Great Lakes and into <;ota, lnd the headwaters o f t h e Columbia and December in certain New York lakes . The Fraser Rivers and Vancouver Island, Brit time of spawning varies from year to year , IS'l Columbia. The species has been intro and the duration of the breeding season duced Widely In lakes of the west. Its prin varies in different waters. It lasts for as c Ipal cente r of abundance formerly was in t h e little as a week in certain inland lakes but uppe r Gre.lt LaKe!o, where for many year s may continue for a month or more in the he Innual comme rcial production ave raged Great Lakes . nl'drl} 15 millIon pounds . In re c ent years , tlO\\t'ver, predJtton by the sea lamprey Typical spawning grounds of lake trout I', '" y c IJ11 '11 r 11U~1 has brought the species are rocky (gravel, rubble, boulders), wave nCdr e-tln(tlon In Lakes Huron a nd Mlchi or current- swept shoals, at water depths ~ 111, dnd h j s g reatl y reduced the population that range from a few inches in some inland Ir •. 'r'"e ~uperlor. lake s to as much as 100 feet in the Great Lakes . Even greater depths and a different Ldh' rout spend most of their lIve in bottom t ype were frequented by lake trout ttd' I, "per vat,'rs of the cold lakes Inwhich of southern Lake Michigan (before their 'h' \ uc (ur . rhey move a bout extensively, near extinction), where spawning occurred ho .... \,.r, dnd md') be found at a ny depths at on a clay bottom at depths a great as 200 (cr .la. Cd ... ons or localItIe s . In the Great f eet and more . As a further variation in L.i}" t1t~\ Llr' usually most a bundant at spawning habitat , some lake trout migrat I"f'h be \l'l'n 100 and 300 feet. Generally up tributary streams, where they pawn I. l :IVP .It or n ar the bottom, but some over rocky bottom . (](ctlr .d.,o In the open water, far o ff c, -flt'rt> ht yare caught commercially In Lake Superior, differ nt races o f t't :lOe., or In gill nets su -pended blow siscowets spawn a t depths ranging from 50 ddt to. In smdlle r Inland lake In th to more than 300 f t, and on dat s ext nd of heir rang, th warming ing from early June to late Nov mb r . trlc lak rout 0 d, "p '.1 'r 10 "umm r . They eldom remain Spawmng behavior . -- 0 n t or r dd i for t. nded pt rlod" 10 a r With m built by lak rout. Th mal . which ou - r '.1 'r han 50 F . : t h r pr fer numb r th f mal s on th p wning of about 500 F . 51 cowe o f ground , congrega t on th br ding ar a 2 before the females. They cruise over t he year ea lier (or at a mall r n bottom and clean it of debris, alga l growth, others . In gen r al, males ma ur n and slime by fanning and rubbing the rocks earlier age and smaller ize han C mdl of the substratum. Activity on the spawning Varying number s of matur lak ro In grounds oc c urs mostly betwee n dusk and some lakes do not spawn eachy ar, bu m y midnight and reaches its p e ak shortly after skip o ne or more spawnln g s ason , dUrin dark, a lthough a few males may be pre sent which eggs or m llt are no produced. at all time s of the day dur ing the height of the breeding season. Lake trout are poly P r oduction o f eggs .-- Ma urlng ... In h gamous; there is no vigorous f ighting or ovaries o f female lake t rout undergo h defense o f territory. During courtship a m ajor portion o f t heir development dUrin marked, but transitory color c hange o ccur s the 5 months preceding the pawning eon. among the male s: the back be come slight At the beginning of this period th paIr d and silvery and a dark, lustrous stripe ap ovaries are elongated, fleshy o r gans lYIn pear s along each side. Spawning may o ccur b eneath the air bladder ; th IT w 19h 1 I !:> s with only one or two males a nd one f emale than 2 percent o f the total weight o f he fl h . taking part, or several males a nd several Just before spawning the heavily lad n females may compose a compact s p a wning ovaries f ill a large proportion of th body group. Typically, one or more male s ap ca vity and m ake up about 12 to 18 p rc n proa ch a nd nudge or nip at a female a nd of t he weight of the f ish . M ature eggs in he then press against her side , with the vent s ovaries a re l a rg e (1 / 6- to 1/ 4 - tnch diam in close proximit y . The bodie s of t he f i s h eter) for a fre shwater specie, but h Ir quiver, their mouths are u s u a lly open, a nd size varies c onsiderably among Lsh of the dor sal fin of the male is held erec t. different s ubpopulat ions or f rom dlff r n E a ch act lasts for only a f ew s econd s a nd localities. The size is not co r reldted with undoubtedly must be repea ted a number of the size of the parent; small lake rou time s before spawning is completed. The produce fewer, but n ot smaller , egg ... thdn f ish breed a t r a ndom over the cleaned a r ea do lar ge lake trout. and make no a ttempt to bury or otherwise care for the e ggs, which sink into c revices among the rocks. The number of eggs produced by ldke rou often varies w idely a mong Indivldudls of the Individual male lake trout may remain on same size, but shows an average Increa"t or near the spawning grounds fo r 3 weeks with in creasing size of the fish. The numb r or more, but after the spawning season is laid during a spawning sea son range s frorr over the adults d isper se widely from t he a bout 1, 000 f or small fish (15 Inche ... long) bre e ding area . Although lake trout may from inla nd lakes to as mal1Y as \ H, OOO for move to distant points between breeding large l ake trout (32 Inches long) from thl s easons, most r eturn to the same spawning Grea t Lakes . The number o f eggs producec' grounds each year. per pound o f weight of the parent ran~e from 400 t o \,200 and averages dbou 700; Size and age at maturity.--Size and a ge this value t ends to be higher for Id r ge han a t sexual maturity vary widely among lake for s m all f ish. t rout in different waters or f rom different s Ubpopula t ions . In c ertain Canadian l a kes After the mature eggs have bCf"n ldld, some l ake trout matur e at length s a s small two sizes of tiny eggs (one group dbou ht as 12 inches, whereas in Lake Super ior Slze of apinheadandtheo her s 111 smd:lt'r many do not mature until they are more remain distributed through the OVdr than double this length (although fish of some ti s sue. races mature a t lengths as short as 14 inches) . Lake trout in some lakes or under Eggs on the spawning grounds.- - Ldl 3 Eggs are so difficult t o collect from their AGE AND GROWTH rocky environment that few egg-fertility studies have been made. It appears, how The rate of growth varies widely among ever, that natura l spawning is efficient. In individual lake trout from the same race one sample of more than 300 e gg s collected or the same lake, as well as among fish from shallow-water s pawning grounds in from different race s or water s. In Lake Otsego Lake, New York, 94 percent h a d Mic higan, the average total length at the end been fertilized and 79 percent were s till of the f ifth year of life ha s be n estimated ali ve after ha vin g been on the lake bottom on the b asis of scale examinat i ons to be for a month. a bout 16 inches (14 to 18 inches in different collections), whereas in Grea t Bear Lake, L ake trout eggs develop slowly in the col d Canada, 10 years a re required to attain this w a ter in which they are laid and may re size . Tagged native lake t rout recovered in quire as much as 4 months or longer to Lake Superior or Lake Michigan, 1 or more complete their embryonic development. The year s a fter marking, had an average growth eggs hatch into relatively helpless larvae, of about 3 inches per year for fi sh 12 to 26 a bout 0.6 inch long, with a large yolk sac inches long . Thu s the applicatlOn of a "rule and a large mouth. of thumb " of about 3 inches of growth per year provides reasonable estimates of the age of the smaller lake trout f rom these THE YOUNG waters . At grea.t er size the average annual increment of length decreases steadIly and Newly hatched lake trout undergo their may amount to as little as 1/2 inch or les s early development in the protection of the for fish over 36 inches long. rocks of the spawning grounds. In about 1 month, after the absorptlOn of part of their Although rate of growth in length de large yolk supply, they enter deeper water, creases greatly among fish of large size, beyond the spawning grounds (except in far the rate of increase in weight r i s e s northern water s, where they remain a mong markedly. This is shown by table 1, which the boulders near shore for severalyears). gives the average weight o f fish of different In Lake Superior, most small lake trout total lengths, between 8 and 42 inches, for remain at depths of 100 fe e t or less lake trout from Lake Super ior . throughout the fir st summer, but ar e found in deeper water after the equinoctial storms Lake trout are long-Ii ved and a ttain large of fall. size. Slow- growing f ish in cold northern water s have attained age s estimated to be as The early growth of lake trout, during high as 37 years . Two f ish hatched from the period when the yolk IS being absorbed, eggs obtained from Lake Superior stocks is slow; the rate increase~ markedly from were held in hatcheries through life spans late July to mid-September, and declines of 24 and 28 year s . The largest lake trout again to a slower rate in the fall. By the on record was 49.5 inches long and weighed end of the fir st full year of life the aver age 102 pounds; it was caught in a gill net in length ranges from less than 2-1 / 2 inches Lake A tha baska , S a skatchewan, in 1961 . in the far north to nearly 4 inches in south ern Lake Superior, and 3-1/ 2 to 5 inches in Lake Michigan. FOOD The earliest food of lake trout, eaten Lake trout feed almost exclusively on before the yolk is completely a b sorbed, other animals. Except for this generality, consists of microscopic anim a l life (zoo the composition of the diet varies widely plankton) and tiny insects. In water s where among fish of different size s and from it occurs, a nutritious, 1/2- to 3/ 4-inch different water s. Small lake trout fe e d fir s t long crustacean, the opossum shrimp, be on minute crustaceans and soon add l arg er comes the favorite food by mid-July of the crustaceans (such as opos sum shr imp when first summer, and remains the principal they are available)' insects, and s m all fish item of diet for the next several years. By (especially s c ulpins). By the time the fish' way of fore showing their later fish- eating reach a length of 15 to 18 inches the diet i s h a b its, lake trout begin to eat occasional principally fish . The fishes eaten b y l ake tiny larval fish at the age of about 4 mon ths trout are of whatever kin d happ e n t o be and at a length of only 1_1/ 2 inches. available i n the immed iate e n vironment. 4 Table 1 .-- Length- weight relation of lake t rout from Lake Sup rior Number Number Total Average Total Avera of of length weight length weight fish f ish In ches Pounds Inche Pound. 8 134 0.1 26 43 5 .6 10 162 0.3 28 80 7.3 12 135 0.5 30 81 8 . 8 14 141 0.7 32 42 10. 7 16 120 1.1 34 23 13.3 18 141 1.7 36 12 16.4 20 191 2.4 38 8 18. 3 22 144 3.2 40 16 23 . 1 24 49 4.3 42 14 28 .4 In the upper Great Lakes, ciscoes of MOVEMENT several species make up a major portion of the diet of adult lake t r 0 u t; other In Lake Superior, individuals from om coregonines, sculpins, smelt, and a variety races of native lake trout move throughou of small forage species also contribute. In the lake. Tagged individuals have be n re Lake Ontario, as in certain New York l akes, covered as far as 300 miles from th taggmg al~wives are important as lake trout food. locality, and one fish is known to hav In still other waters where food habits have traveled 190 miles within 19 days. Llk been studied, yellow perch, s melt, sucker s wise, In Lake Michigan, t agg d lak trou and minnows are important items in the have moved more than 200 mil s from th diet. place of release. In both lakes, the larg r f ish moved the greater distances. Smdll 'r tagged fish, less than about 16 to 18 Inch ~ Small lake trout have been found only in long, seldom were recaptur d at dlstanc " frequently in the stomachs of l a rger f ish, greater than 50 miles from th Ir homt' probably because of the greater relative water s. abundance of other forage species rather than because of any scruple s against can In contrast to the far-ranging habl s of nibalism. Large l ake trout have bee n ob lake trout of some races, v ry few fl"h served to feed voraciously on newly s tocked tagged In South Bay, Lake Huron, w r' lal e trout fingerlings which were concen recaptured in waters outside of the BdV. trated near the pla nting locality. In certain Similarly, in Great Bear Lak , Canadd, inland lakes it is believed tha t preda t ion by subpopulations of lake trout only 8 mil 5 large lake trout may severely limit the apart showed no tendency to lnt rmlx. density of their own population. Although most adult lake trout eat fish, ARTIFICIAL PROPAGATION some stomach s from this species collected from a number of waters have contained Lake trout are hatch d and I' ar d ar 1- large qua ntities of terre strial in sects. In ficially by conservatIOn agencl !> at varlOU still another departure from the c ustomary localities In their geographiC I' nge. Egg fish diet, lake trout of some inland lakes are taken from fish caught In n s d~ feed largely on zoopla nkton, especially in their spawnmg grounds, or from ha ch ry summer, when warming of the water dis reared brood stocks. Eggs and mil d l't' courage the f ish from reaching the upper stripped from npe fish by manual pI' levels occupied b y their usual for age . In on the Side of their bellies, coll c d m , populations re stricted to invertebrate food sUitable cont ainer, and thoroughly ml d. dur ing much of the growing ea on, the After the fertl11 z d eggs have b 'n wa h d growth rate often i slower than in popula and are water-hard ned, th y ar r n - tion which have uitable fo rage f ish avaIl fer red to hatchen s, where th y ar mc - a ble throughout the year . bated m hallow trays u p nd d m tro h 5 of flowing water . The length of the incuba hybrid f ish (called "splake," "wendigo," or tion period depends on the water tempera "moulac ") shows fa s t growth (hybrid vigor), ture. Hatching occurs in a bout 2 months at reach es good size , and is reported to fight 47 0 F., 4 months a t 390 F., a nd requires well when hooked. more than 5 months at 35 0 F. The h atching percentage varies widel y in different lots of eggs but averages about 65. LAKE TROUT FISHERIES New ly hatched fr y have l arge yolk sacs Lake trout are so widely disper ed in and are relati vel y helple s s. They begin feed their environment tha t dense popula t ions or ing and swimming actively within a bout a high production in any given water are un month. Their f irst food in the hat c hery ordi usual. In inland wat ers the average annual narily is finely ground meat, such as beef catch by sport f ishing seldom exceeds 1 liver or beef heart. Other meats or dry pound per surface acre and the far-flung a nimal and vegetable meals may be added to commercial fishery o f the upper Great their diet later. Lakes has produced an average o f less than one-half pound per acre per year . Lake trout are stocked at various SIzes b etween the time of hatching and the a ge of Lake trout are highly desirable game f ish, 2 y ears. Both the cost of rearing and the de spite the fact that the lr fight at the end of p rob a b ility of later survival increase m pro a line is less spectacular than that offered portion to the duration o fthe rearmg per lod . by some other member s of the salmon Currently, most young are stocked In the family. They are more vulnerable than most spring of the second year, when lengths may species to hook-and-lme fishing, and de average 4 to 5 inches. Experiments with fin pletlOn of stocks m inland lakes has been clipped lake trout stocked in Lake Superior shown to re sult from angling alone . Most have demonstrated marked increases in sport flshmg is by trolling at considerable survival when fish are held through their depths (50 to 200 feet, depending on the first winter before planting. The most favor character ofthe fishing grounds) with copper able re sult s from lake trout stocking are or SIlver spoons, splnners, or !lve bait. obtained from new introductions into suit able wat ers, or from plantings made to In the upper Great Lakes " deep- sea trol maintain populations in lakes in which the llng" for lake trout was so effective that it species fails to reproduce successfully. The was a recognlzed and productive com value o f stocking lake trout is questionable mercial fishmg method (average annual pro in lakes where natural reproduction is suf duction, 1944- 50. m Lake Superior - - 86,000 f icient to sustain the populations. pounds). Sport trolling from party boats Until recent years, fe w lake trout were (cabin crUlsers or renovated fishing tugs) reared to maturity in hatcheries for brood began more than 30 year s ago and was gain stock, principally becaus e of the long period mg popularity rapidly prior to the extensive (4-1/2 to 6-1/ 2 years or more) required destruction o f lake trout stocks by the sea before the first eggs are produced. After the lamprey. Many thousands of pounds wer e invasion of the upper Great Lakes by t he sea taken. The average size in various y ears lamprey threatened the extinction of lake and localitie s ranged up to 8 pounds, but trout, it became clear that lar ge number s of many 10 - to l5-pound f ish and some 25- hatchery-reared fish would be needed to aid pounders were caught . A record f ish caught in the rehabilitation of the species . Rearing on hook and line in Lake Superior in May techniques were improved , and b rood stocks 1952 was 51- 1/2 inches long a nd weighed 63 were developed, particularly in the State of pounds, 2 ounces. The G reat L akes sport Michigan, where current production of lake fi shery for lake trout was lim ited for some trout eggs from hatc hery- reared brood years almost exclusively to L ake Superior stock exceeds 6 million per year. and has now practically disappeared from this lake as well, because of destruction of In recent year s, intere st ha s bee n revi ved, lake trout stocks by the sea lamprey . particularly in Canada, in the production of hybrids from cros s - breeding female lake In addition to dee p- sea trolling, " bobbing" trout with m ale brook trout. These hybr i d s t h r ough the ice is a well-known method of have bee n produc ed experimentally on a the sport f isher y . Either live baitisusedor number of occasions In fish- cultural his piece s of l ake herring a re placed on hooks tory, but seldom on alar ge scale. The in a manner to simulate live f ish when they 6 are bobbed up a nd dow n near t he bottom The commercial fishery in Lake Superior (often a t depths of 75 to 100 fee t o r more). was closed in mid-1962, and the catch of Bobbing through the ice is a popular win ter lake trou t restricted to the minimum num s po r t a nd fo r m a n y year s was especially bers necessary for scientific research on pro ductive in c e r tain sheltered areas in the lake trout- sea lamprey relationship. L ake Super ior. The closure of the Lake Superior fishery T he upper Great Lakes area was the major followed the demonstration of the effective cente r fo r commercial production of lake ne s s of sea lamprey control in the spring of t r out for many year s. Fish tugs were op 1962, when the number of a dult sea lampreys erated out of most port citie s and towns moving up Lake Superior tributaries to lining the shores. Gill nets accounted for spawn was reduced by 86 percent from 1961. more than 70 percent of the production and The control followed more than 15 year s of set- h ooks were next in importance; im research by Federal, Provincial, and State pou nding nets, c ommercial trolling, and agencies of the United States and Canada, in oth er methods combined yielded only about an effort coordinated since 1955 by the Great 5 percent of the total commercial catch. In Lakes Fishery Commission, an interna the 10- year period 1931-40, the average tional body which was established by treaty annual production in the upper Grea t Lakes between the United States and Canada. The was 14.7 million pou nds (w orth well over $ 7 definiti ve breakthrough was the discovery of million at present prices). Of this total, a chemical (3-trifluormethyl-4-nitrophenol) Lake Michigan produced 36 percent, L ake that is toxic to sea lamprey larvae but harm Huron 34 percent, and Lake Superior 3 0 per Ie s s to other animals. This larvicide was cent. Forty-two percent of the total catch applied to all Lake Superior tributaries was landed in Michigan ports, 33 percent in known to be inhabited by sea lamprey Ontario, 19 in Wisconsin, 3 in Minnesota, larvae. 2 in Illinois, and 1 percent in Indiana. In addition to the Great Lakes, lake trout The sharp decrease in numbers of sea are caught commercially in a number of lampreys in Lake Superior allowed the l ake large inland lakes of Canada. trout population to begin recovery. The num ber s of l ake trout with lamprey woun ds d e creased markedly, and more of the fi sh THE LAKE TROUT AND THE SEA grew to large size. Sexually mature f i sh of LAMPREY IN THE GREAT LAKES some races practically had been elimin a t ed by the sea lamprey; consequently, little or The commercial production of lake trout no natural reproduction occurred in e x ten in the upper Great Lakes during the past 50 sive sec tions of Lake Superior for at least ye r s is shown in the accompanying graph. ') years. Large numbers of hatchery-reared In each lake, a long period of fluctuating but fi sh, each marked by the removal of one or relatively high production was followed by more fins, have been stocked in rece nt y ears the catastrophic collapse of the fishery in to !1.elp fill in the missing year classes; recen t years, a fter the sea lamprey suc about 1, 8 00,000 yearling lake trout were c essively invaded Lake s Huron, Michigan, planted in 1962 alone. and Superior. In Lake Huron, a production which exceeded 5 million pounds as recently Experimental sea lamprey control t hus as 1938 dropped to les s than400,000 pounds far has been concentrated in Lake Supe rior, in 1947 and 1,000 pounds in 1959; in Lake where a remnant of the native lake trou t Mich igan, the rate of decline in cat ch was population still remains. The appa rently e v e n more precipitous, from more than 5 successful control efforts underway there m illio n pounds in 1945 to only 54,000 pounds offer substantial hope that the spec ies will in 1950 and 400 pounds in 1953; in Lake Su again be restored to its former levelof im perior, production dwindled from 4,700,000 portance in the sport and commercial f ish pounds in 1950 to 368,000 pounds in 1961. ery throughout the upper Great Lakes. 7 9.------r------,r------.------.------~--~ 8 E 5 / c o ) U I ~ 4 u 1 o I '-- \ 0... / \ \ 0 3 \ \ u \ '-- \ Q) \ E \ \ ~ E 2 \ \ o \ U \ -- Lake Michigan '\ Lake Huron , \ -- Lake Superior \ \ ~ 1910 1930 1935 1960 Commercial production of lake trOllt In Lakes Midugan, Huron, and Superior. MS # 131 8 Created in 1849, the U.s. Department of the Interior is roncerned with the management, conservation, and development of the Nation's water, fish, wildlife, mineral, forest, and park and recreanonal resources. It also has major responsibilities for Indian and Territorial affairs . As the Nation' s prlnC'lpal conservation agency, the Department works to assure that nonr enewable re sources are developt:d and used wisely, that park and recreational resour ces are conserved for the future, and that renewable resources make their full contribution to the progress, prosperity, and security of the United States--now and in the future. GP O 867 . 383 UNITED STATES POSTAGE A TD FEES PA.ID DEPARTMENT OF THE INTERIOR u .S. DEPART IE T OF THE INTERIOR FISH AND WILDLIFE SERVICE BUREAU OF COMMERCIAL FISIIERIES WASHINGTON, D .C. 20240