MFR PAPER 1063
Northern Hemisphere fish might tap the rich kn/J stocks of the Southern Ocean.
Salmon-Future Harvest from the Antarctic Ocean?
TIMOTHY JOYNER, CONRAD V. W. MAHNKEN, and ROBERT C. CLARK, JR.
INTRODUCTION
The ocean surrou nding the Ant arctic continent IS an e normou res en oir of protein. A worl d inc reas ingl~ beset with food shortage can not for long afford to let it re main unhane~ted. The ke) to thi un tapped bount) I a little red cru ta cean. Euphausia superha. that looks like a small shrimp and is commonl y Krill, a small crustacean of the species Euphausia superba, forms a major part of the food called I·.rill A product of the im supply of the whale population of the Southern Ocean . mense fertillt~ of the Southern Ocean. its food suppl) is a sured by lush estimated th e potenti al a nnual catch ought we not to try to get help from pastures of single-cell ed marine pl a nts of krill to be 100 mill ion tons . some other creature better equipped In the fertde zone of circumpolar Thi eno rmous abundance of krill by nature to do it ? To a limited up\\elling (Figure I). Second in the ha been a source of fascination to extent baleen whales once did this. short A ntarctic food chai n. kri II fis hing a nd food interests throughout H owever. as they breed slowly and underlies the remaining links made the ~orld . The So\iet and the Japa produce few offspri ng. the stocks up of quid. penguins. sea birds. seals. nese are developing techniques for were 0 decimated by inten ive whale and \\ hale. processing krill into a palatable food fishing that they are now threatened Inten I\e stud) b~ So\iet scienti ts product. Harves ting it. though. is a with extinction . Since none of the of data obtained b) fi hery research di ffic ult and expensive proposition. other links of the short Antarctic \essels. operating in Antarctic waters requiring la rge vessels operating for food chain that depend on krill could since the earl) 1960·s. has produced extended peri ods fa r from thei rhome with tand intensi e harve ting either. e\ Idence that e\.ploitation of krill re ports. With the skyrocketing price it would eem logical to e amine th e sources could at least double the of petroleum fu els brought on by the prospects for introduction of pecies present global production of aquatic world-wide energy crisis. the pro from the great diversity of arctic a nd animals. In late 1973. scientists of th e pects for a profitable high eas krill subarctic fauna . Succe in introduc AII-Cmon Institute of larine F ish fis hery now seem dim indeed . ing exotic species to Antarctic waters eries and Oceanograph) (V I RO) would be favored by: PROSPECTS FOR AN (1) Adaplahiliry 10 life Of sea alld T imoth) Jo), ner, Conrad V. W. Mahnken, a nd R o be rt C. Clark, ALTERNATIVE HARVEST a propellsiry ro feed 011 lIlarille plallk Jr .. are all members of the staff roll.-Except for the barren. ice of the North" est F isherie Cen there another way of tapping covered Antarctic continent. there is ter, National Marine Fisheri es little land in the Southern Ocean. en ice, NOAA, 2725 Mont this ast Antarctic reser oir of pro tein? Since we cannot yet hane t lake Bh d. E., Seattle, W A Figure 1.-Krill resources in the Southern 98112. krill economically by our elve . Ocean-summer distribution.
20 150
170
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o
~I Onl) crcaturc~ \Icll auaptcu to oCCdn e\l)\IC species to hc Inlrlluu\.:Cu to lor s.tilllon 01 all spccic, Optll11Um lifc anu ablc to fccu on planh.ton \lllarctlL scas should hc e"S\ tn h"r tClllpcraturc, lor the u(;'elorrnenl \\oulu bc able to thnlc lll1 the abull \esl allu t\l pw\.:css 1111(1 " Icaull) ,wd grll\lth 1I1 'ialllllln VM} hetwecn uant h.nll . marh.etahlc produLI 01 ,"I thc SPCCICS thcw e tremc' ,Iccoruing tll ~recie'i (2) Adu[lluhilily 10 (old II ,1/ , I \Ie ha\c \.:\lll'ldcICU s,tillWIl arc h\
Tolerable Preferred Reference months range range for preferred Bo unued on the nort h b) the u b Species C C range tropical Conlergence near lat. ~O O
Sockeye 1- 15 2 .3-9 May September anu on the ,outh b) the ice-co\ered Chum 1- 15 2.3-11 May Seplember Illas~ of Antarctica. strong lIe terl) Pink 3-15 4-11 May June Coho 5-15 7-12 May June July \\Ind uri\e the waters of the o uthern Chinook 2-13 7-10 July Augusl. Seplember Cherry (masou) 5-15 7- 12 March . Apn l , May Figure 2.-The West Wind Drift.
22 ----~------~~--~~~~_=~9r_°-~-_=~-E_~==:s~7~0~------5 0
30 130
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Ll-t---H-tt/-O Antarctica
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50 90
23 110 90 50
150
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30
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24 Ocean continuously eastward In a be carri ed rather q ui ckly back to the Chi le. Selected races of coho and current known as the W e t Wind coast of South Island and woul d cherry salmon would he the he~t Drift (Fi gure 2). Upwell ing inside probably tend to enter their home choices for this region . the Antarctic Con ve rge nce brings to streams as relatively small fis h . T his the su rface nutrients di ssolved in may well be the case with th e resid ua l SEEDING THE SOUTHERN deeper waters from decayed, sinking stocks from the Q uinnat (chinook) OCEAN WITH SALMON bodies o f ma ri ne o rga ni sms and fro m salmon tra nspla nted to th e South fin ely ground rock po wder dro pped Island in the early years of thi s centu ry. From the foregoi ng it can be de by melting glaci al ice. These nutrients T he southern e'(tremities of Argen duced that the '" ater of the West are carried no rthward to th e region ti na and C hile and the Ke rguelen Wind Drift provide the Southern of th e Conve rgence, in the vic inity Isla nds li e close to the A nta rctic Hemisphere's most favorable envIron 0 of lat. 50 S, by co ld surface waters Convergence and kri ll -ri ch wate rs. In ment for the oceanic part of the life fl owing outward fro m Anta rcti ca. both areas a cool. wet Marine West cycle of most salmon. In the zone of Coast C li mate prevail s. Combined upwelling inside the Antarctic Con Land Masses with the deeply in dented coa tli nes vergence where great concentralion~ ri ing to hill y or mountain ous ter of krill are found, water temperatures There is little penetrati o n by land rain-whi ch typifies these two re range from about r to about 2 C. in to the Southern O cean. T asma ni a, gio ns-environments are produced Such a regime would favor the more ew Zealand's South Isla nd, a nd the tha t are st rik ingly imilar to those of northerly distributed stocks of chum, southern end of South Ameri ca a re southeastern Alaska and the Aleutian sockeye, and pink salmon as can the o nl y signi fica nt la nd masse im Islands, which contain some excellent didates for transplantll1g to the Ant pinging upo n it. There a re also the salmon spawning streams. In Chile arctic (Figure 3), The stage of develop Falkla nd, South Georgia, a nd Ke r si nce 1905, a number of attempts ment at which di fferent species ~)f guelen Isla nd group a nd a few minor have been made to establish Pacific salmon can enter salt water is also Antarcti c isla nds. salmon in the streams of the lake an important con ideration for select T asmani a and South Island li e at district lying between lat. 38° and ing appropriate stock~ for transplant th e no rthern ex tre mity of the South _nos. T hese attempts have not met ing. The earlier young salmon are ern Ocean whe re th e maj o r di vergence wi th much success. Chilean biologists, released to go to ea, the lower is the of the West Wind Drift splits off a nd convinced that the environment in cost of operating hatcheries Chum heads north ward through th e Ta man their country should favor the intro and pink salmon fry can tolerate salt Sea to merge with the warm waters duction of salmon, ascribe the e fail water as soon a the yolk sac IS ab of the Australi an C urre nt. On the ures to the small numbers of ova that sorbed. If released at this stage, no eastern side of South Isla nd, over the were involved, poor handling, and artificial feeding is necessary and New Zealand Pl ateau a nd the C hath predation on the few surviving fry hatchery costs are minimal. a m Ri se, a weak, cl ockwise gy re by brown and rainbow trout. We Although there is little land 111 sends water no rthward alo ng the coast wou ld like to point out an oceano the Southern Ocean for pro\idll1g to the Subtropi cal Con ve rgence. Salm graphic feature which weighs against the freshwater environment essential on mi gra ting to sea from Tasma ni a the survival of ea-going salmon in for the early life of salmon. the top or the west coast o f New Zeala nd troduced into that region. In those ography and climate of the southern woul d have to swim great d istances latitudes, the dominant oceanographic tip of South America closely parallel against the current to reach the Ant feature is the northward-moving Hum those of southeastern Alaska. The arctic Con ve rge nce. Those drifting boldt Current. Rich in feed and cooled mean annual air and ea-surface no rth wi th the current woul d probably by the upwel ling of deep water along temperatures fall between rand H (. peri sh as they were carried into the the coast. it would be an attractive Starting from a coast lying dlreLtI) subtropics. Salm o n e ntering the sea lu re to sea-going salmon. Moving alongside the main body of the West on the east side of ew Zealand randomly as they fed on the abundant Wind Drift as it funnels through the would tend to circle in the gyre over small ea life. they would be carried constriction of Drake Pas age, salmon th e sea-botto m pl ateau and probably north and west by the current until migrating to sea from treams In woul d not find suitabl e feed as readi ly it merged with the warm waters of southern Argentll1a and Chile should as they wo ul d have if they had gotten the South Equatorial Current. Such have little difficult) In finding the into the krill of th e W est W in d Drift. a journey would be fatal for most krill inside the Antarctic OJ1\cr Since the gy re is sma ll. they would almon. Only almon that ha\e a gence. Assuming that the) \\ould propensity for remaining clo e in mO\e randomly as they fed on krill. shore during their life at sea could the) would be carned easl\\ard in Figure 3.-Salmon environment in the Southern Ocean . become established in south-central the current at an a\erage speed of I
25 h.not. At lat. 50° they would complete one circuit in about ~ year and two circuits in 4 years . Or. th ey mi ght choose to stay in the rich krill con centrations of the Scotia Sea to the southeast of Cape H o rn . In either event. the mingling of freshwate r runoff from the A ndes M ountains ~i t h the waters of th e W est Wind Drift should lead them readi ly back to the coastal area where they were spawned . The Kerguelen Islands in the In di an Ocean sector. wi th mean annual ai r a nd sea-surface temperatures close to 5 C. lying directly in the zone of the Antarctic Convergence. could also possibl) serve as a la nd base for transplanting salmon into th e Southern Ocean. Introduction of salm on on a scale sufficient to ge nerate a signi fi ca nt fis her) in the Southern Hemi sphere Figure 4.-Low-cost gravel incubators, Quinaull Indian Reservation, Washington . will have to confront the basic pro b lem of initiall y injecting la rge numbe rs adult pink salmon entered stream of suitably adapted stocks from a in the Murman k area. with smaller ~trategica l l) located land ba e into numbers showing up along the coasts the West Wi nd Drift close to the of N orway, Iceland, and Great Brit Antarctic Convergence . The initial ain . The runs subsequently dwindled, Injection should be ufficiently mas as the roe from the returni ng spawners si\e th at enough would survive the peri shed during incubation. the win difficulties of inverted seasons and an ters being considerably colder around alien geography to produce a growing Murmansk than on Sakhalin. home population with each successive cycle. of the parent stock. These Soviet Stoch.s of chum and possibly sockeye ex periences suggest strongly that plans or pin h. salmon ada pted to Arctic for mass transplants to the Southern ~a t e r s released from southern Chile Ocean should involve initial releases and Argentina or the Kerguelen Is of millions of fi sh. There should also lands, should move across the tempera be provisions for recapture of a sig ture gradient u nt il th ey passed the nificant fracti on of the homing migra 5 C isotherm Just inside the A ntarctic ti on to ta ke eggs for a rtifici al incuba Com ergcnce T here they shoul d find ti on. It would be too risky to rely plcnt) of h.ri II on natural stream spawning to main SO Vl ct experience ~It h transplant tain the transplanted population. In g PIn h. salmon to the Murmansk In our opinion. a hatchery and area of th e Euro pean Arctic from suita ble fi sh traps should be built on Sah.h alln Isl and In the Pacific Ocean the southern coast of Chile or Argen Figure 5.-Detail-gravel incubator. prO\ Id e us ~ith ome valuabl e in tina . As many eyed eggs of Arctic \i ghh regarding the pro blem of la rge stocks of chum salmon as could be easi ly by birds. The hatchery would \cak tran~plants . From 1956 to 196 1. coll ected would be sh ipped to th e con ist of low-co t gravel type incuba tr a n,fcr~ of from 4 to 46 milli o n roe hatche ry for incubation and rel eased tors (Figures 4. 5). Feedin g would \\ ere made bet~ecn fi~h culture sta as swi m-up fry . The hatchery should not be neces ary as the fry would be tll)n\ In 'ah.halin and I\lurma nsk. be as close to the sea as possi ble so released as soon a the yolk sacs were Ocean un i \ al \\ as good a nd the th at the fry on their way downstream absorbed . Returning adult would be ret urn, peah. ed In 1960 ~ hen 300.000 to the ocean would not be spotted collected in A laska-type salmon traps
26 Figure 7.-Closeup view of floating salmon trap, Alaska . (Photograph court.sy 01 Fllh.r .. Research Institute, University of Washington.)
FLOATING SALMON TRAP 111111a
Figure 5.-Aerlal view of floating salmon trap, Alaska .
Figure 8.-0etail, noatong salmon trap Aluka From Sunciltro G I a T 7 Com .,c Fishing Ve ..els and Gear US FISh and W,ldhle SeN ce C reu .,
27 Icebergs of the Southern Ocean . ( Photograph c ourtesy of Wm . H. Curtsinger , National Science Foundation.) of pfll\Cn crtlclenC) (Figures 6-8). concentratio nsl. In Rus ian. Tr. Vses. currents in the Scotia Sea l . In Russia n. Nauchno-is led. Inst. Morsk. Rybn. K hoz. Tr. Vses. Na uchno-issled . Inst. Mo rsk . l g~., \\llulu he ,hipped by air In re Okeanogr. 79:31-40. (Transl .. p. 27-36 Rybn. Khoz. Okeanogr . 79:4 1-49. (Tra nsl. . frl'Lr
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