Antarctic KriSI: Problems and Potential
Transcription
Antarctic KriSI: Problems and Potential
Marine Technology Society Journal 17(4)"5Q-35, W i n t e r 1983-84 Antarctic KriSI: Problems and Potential Valerie M. Fogleman Texas Tech University Lubbock, Texas INTRODUCTION Euphausia superba resemble luminescent shrimps when grown. They begin life as an egg, having been spawned at the ocean's surface during the Antarctic summer. 6 The eggs then sink, cleave, and hatch. After hatching, the juvenile krill begin their slow ascent back to the ocean's surface, which they reach upon maturity. For the remainder of their lives, aduit krill live in the top hundred meters of the ocean, predominantly in the top ten meters. 3 Krill. Millions upon millions of them. Blue whales eat nothing else, migrating thousands of miles to the icy waters of the Antarctic (see Figure 1) just to feed on krill. During the feeding period, a single adult blue whale might eat 3 tons of krill in one day. Whalingmen who saw the whales feeding said they were easiest to kill then; the whales would be so intent on feeding that they were oblivious to anything else. About 150,000 blue whales thrived on krill. But that of course was before the whalers. This theory of krill's life cycle was successfully tested recently. Early larvae, adolescents, and adult krill were subjected to high pressures similar to those experienced in deep water (i.e., 400 to 1,000 meters). The adolescent and adult krill underwent violent convulsions, but the larvae did not. 7 It did not take the whalers long to kill the blue whales. Between 1910 and 1925 they killed 47,200. In the winter of 1930-1931 alone they killed another 29,410.' Barely enough blue whales remain today to cause a ripple in the krill population. A tragedy really. All those millions of krill being wasted when people are starving. Maybe people could eat krill? Krill could even be the solution to a starving world's hunger problem. Or could it? Adult krill can attain a size of 5 centimeters, 3 but size is not an indication of age. If krill which survive the Antarctic winter (spent under the pack ice) encounter poor feeding conditions, they are able to decrease in size, while at the same time advancing in maturity. 8 Starvation conditions can also cause adult krill to decrease in size, while losing their sexual characteristics and regressing to a juvenile stage.' Differentiation between various age groups of krill is further complicated by the fact that females regress to a more juvenile appearance after mating. This regression supports the supposition that females spawn more than once. 8 Regression of secondary sex characteristics is, In fact, a phenomenon in a large percentage of krill, both male and female. 10 Simplistic? Incredibly so. But given the fact that the krill biomass exceeds the world's tonnage of fishery products, 3 an analysis of the potential of krill as a renewable food resource seems in order. This paper contributes to that analysis in its review of the life cycle of krill, the role of krill in the Antarctic ecosystem, and the interest that krill has attracted thus far in terms of harvesting, processing, and marketing. BIOLOGY OF KRILL Euphausia Krill molt regularly throughout their life cycle (even when they are decreasing in size) 10 and, as in all crustaceans, some do not survive the molting process." It is believed that krill have an ecological mortality of 4 years, but more evidence is needed before this can be predicted with any certainty. 4 Recent experiments indicate that the ecological mortality of krill may even be as high as 7 years.' 2 It is known that the respiration rate of kriil changes as they mature. The rate in juveniles is low; in adolescents it is relatively high; and it decreases again when the krill reach maturation. 13 Tests demonstrate a very low incidence of genetic variability in krill.' 4 superba Krill are euphausiid crustaceans, of which there are eighty-five species worldwide. In the Antarctic region there are eleven species, of which four predominate in the marine ecosystem. In descending order of importance these are: Euphausia superba, E. crystallorophias, Thysanoessa macrura, and E. vallentini. Euphausia superba and Thysanoessa macrura are clrcurnpolar; E. vallentini is circumpolar north of 6G°S; and E. crystallorophias is found only at the edge of Antarctica and under the ice. 3 The largest species of krill, 3 and by far the most dominant in the open ocean, is Euphausia superba.4 5 It is the only species that is commercially important, 6 mostly because of its abundance and its.habit of forming large swarms. References to krill as a potential food resource are always to Euphausia superba. In this paper all further references to krill are to this species. Behavior Krill are filter feeders, trapping their food by inclining themselves to ocean currents. They feed predominantly in the top 25 meters of the Southern Ocean, eating mainly phytoplankton, of which diatoms are the dominant species. 3 They also eat zooplankton, and are cannibalistic. 15 Feeding is usually diurnai. The krill 29 M T S Journal m i * * o West- <p° - East - ANTARCJ1GL CONVERGENCE SOUTH 1 ANTIC OCEAN / b SCO.tlA AMERICA ANTARCTICA s / y / INDIAN OCEAN / SOUTH PACIFIC OCEAN kilometers NEW ZEALAND AUSTRALIA Figure 1. Antarctica. Arrows indicate wind drift. feed at or near the ocean surface until the food supply is exhausted, and then swarm and migrate vertically. Another factor involved in the swarming habit of krill is light intensity. The densest swarms of krill have been seen at the ocean surface during the darkest periods of the austral summer. 3 The reasons for swarming are still unknown, but it is very rare to find krill (10114 which are not in a swarm. 3 Swarms tend to be monospecific: some swarms have krill of only one sex; 16 and others have only juvenile, or only adult members. Swarms of adults end those of larvae are often contiguous. 17 There is, as yet, no generally accepted theory of krill swarming, but it is undisputed that it is a deliberate act. Krill are able to swim, and can maintain swarms v. 17 n. 4 in spite of relatively strong ocean currents. The monospecificity of swarms also suggests a deliberate pattern. 3 Distribution Krill exist south of the Antarctic Convergence. The Convergence is a highly complex band of water encircling Antarctica between approximately 50°S and 55°S. It is unstable, and develops extensive, unpredictable loops and twists as It migrates roughly sixty miles north or south of its mean position. The Convergence is created by the mixing of Antarctic and subantarctic waters. 18 There is a distinct change in temperature as well as in species as one crosses the Convergence. 3 Krill larvae in its early stages are found predominantly in the Bransfield Strait-Weddell Sea area of Antarct i c a . " It has been hypothesized that krill follow the Weddell Sea gyre as they mature, and vast swarms have been located in that area. 3 This theory has been disputed, however. For krill to spawn in the Weddell Sea it was theorized that mature krill would return there with the East Wind Drift, but observations have shown that very few krill exist between 5°E and 20°E, although high concentrations have been .observed east of 20°E. 2 ° A more complex system which may involve seasonal changes has been suggested. 14 Reasons for given sizes and densities of swarms are also complex. High size and density of swarms may be a response to availability of phytoplankton 21 but this is not conclusive. It has been found that in mixed swarms adult krill had usually fed recently, whereas juveniles and subadults often had not. 22 Krill have been sighted congregating and dispersing in welldefined but patchy swarms that have no obvious trend either north to south or east to west. 22 In one area of 1,000 square miles, more than 100,000 swarms were seen, even during periods of bad weather. 20 In another area, swarms stayed together for several days, dispersed into smaller groups, dispersed again, and re-swarmed in another location.' 6 Role of Krill in Antarctic Ecosystem Krill are the key species in the Antarctic ecosystem, both marine and terrestrial. 23 They are the main food resource for fish; squid; penguins; crabeater and leopard seals; and fin, blue, sei, humpback, and minke whales. 6 Some of these species rely solely on krill for their food. Blue whales harvest krill in two distinct ways. They either swim slowly through swarms of them, letting the krill float into their mouths, and then forcing their tongue forward to expel the water; or they spiral up into a swarm, letting their expelled bubbles form a circle around the krill, which is then concentrated into their mouths. 24 Blue whales migrate to Antarctica during the summer months, feeding in the open sea, and increasing their body weight by about fifty percent. 6 It is believed that they eat little or nothM T S Journal ing during the remainder of the year. The blue whales feed on krill measuring about 20-30 millimeters long; minke whales feed on krill measuring 10-20 millimeters long; and fin whales feed on krill measuring 30-40 millimeters long. 3 Crabeater seals are the largest consumers of krill, now that whales are reduced in number. It is estimated that there may be 30 million crabeater seals, 6 mostly feeding at the edge of the pack ice. 23 Crabeater seai3 ere also adapted to feeding on krill. When they close their mouths after taking a mouthful of krill, their upper and lower teeth interlock, allowing the water to drain out as in a sieve. 25 In addition to the animals mentioned, birds such as petrels, chinstrap and adelie penguins, and skuas also rely on krill for at least part of their diet. Petrels swoop down to the ocean surface and glide along, mouths open, scooping krill up. They then contract the pouches of skin below their chins to dispel the water. 25 It is unknown what percentage of krill are eaten by squid, but it is undisputed that krill forms an important part of the squid's diet. 6 The dependence of such a wide variety and number of animals on one species is extremely unusual. 6 As has been mentioned previously, different predators prey upon different sizes of krill so competition for it is mitigated somewhat. The Southern Ocean, however, is in a state of flux as it attempts to reach a new equilibrium without the large populations of whales. 23 Other disturbances are still occurring. Pesticides such as DDT have been found in penguins, skua, fish, and krill. Oil slicks have been sighted in Antarctic waters. These disturbances to the ecosystem cause fluctuations which take a very long time to readjust. 26 Some authors take the view that harvesting kriii will not upset the Antarctic ecosystem, 27 but experts disagree. El-Sayed has conducted experiments showing that the Southern Ocean is much less productive than once imagined, 28 and other studies show that the ocean's productivity is seasonal and regional. 27 Basic facts about krill are still unknown. For example, there may be one population of krill, or there may be several; we do not know. 3 Extensive harvesting of krill may have an insignificant effect on the Antarctic ecosystem, but until that effect is known the potential for inadvertent disruption of the entire ecosystem exists. INTEREST IN KRILL Before 1945 it would have been thought ridiculous to suggest that a fishing fleet harvest Antarctic krill. The technology for such a venture had not been developed, and there were still plenty of fish nearer large markets. 30 Krill had been known about since the 1800's, 3 ' and in 1910, Captain Scott had written that there "are countless thousands of small shrimps [Euphausia]; they can be seen swimming at the edge of every floe and washing about on the overturned pieces. . . . [T]hey afford food for creatures great and small. . . . " 32 31 A large pari of the research by the British ship Discovery was devoted to understanding krill's life cycle. 31 Interest in krill, however, did not become widespread until the 1950's, when it was suggested that there was a surplus, and that surplus krill were a potential human food source. North Atlantic krill (Meganyctipharies norvegica) had been tested in 1906 to judge its potential as human food. The results were less than encouraging. Those tasting it suggested: "however abundant it may become in some subsequent development of economic fishing methods it is never likely to form a welcome addition to the table." 33 The situation had changed by the 1950's. In 1958 there was a whaling fleet in Antarctic waters of 250 ships and 16,000 men, but the whaling industry was declining, as whales were hunted to near-extinction. In the face of this decline, attention began to focus on the whales' former food. An article in Scientific American stated: "The 270 million tons of krill on which the Antarctic whales fed in their heyday would be more than enough to supply the annual [nutritional] requirements of the entire U.S. population." 34 It was envisioned that by the year 1984 the krill fishery would be a major industry. One commentator wrote: "Can we not save the starving children of the world with krill? I am sure we shall . . . The floating fishmeal factories off Peru will be nothing to the fleets of krill ships spread right round the world to the south." The same article expressed skepticism as to whether krill would be palatable to humans, or whether it should be fed to domestic livestock. 35 This reticence was understandable; a contemporary source had compared fried krill to cooked maggots in appearance. 33 By 1968 a scientific journal in Britain ran an article entitled "Krill and Chips?," 36 and a similar publication in the United States carried a report entitled "Surplus Food From Antarctic Waters." 37 The U.S.S.R. had begun research into krill as a food source in 1961,2 and was developing the technology necessary to harvest and process it, 37 Articles suggesting the potential of a krill fishery continued to appear as the amount of krill to be harvested seemed great enough to solve many world food resource problems. 38 By 1970 the U.S.S.R. was marketing kriil products. Japan followed suit, and by 1975 the two countries had investments of about $170 million each in the krill fishery. 39 Interest was growing rapidly as more and more countries began exploratory krill fishing. Soon Chile, Poland, the Federal Republic of Germany, South Korea, Taiwan, and Norway had sent ships to the Southern Ocean; and Chile joined the U.S.S.R. and Japan in marketing krill-based products. 40 Chile had yet another innovative krill-based food. Frozen krill tails were manufactured into krill sticks (similar to fish sticks). 4 ' In 1974 between 20,000 and 40,000 tons of krill were harvested, and today this figure is probably about 100,000 tons annually. 42 32 OWNERSHIP AND MANAGEMENT OF KRILL Antarctica has been under the regime of the Antarctic Treaty since 1959, an agreement whereby ali national claims to territory are frozen. The original treaty included provisions for protecting the Antarctic environment and ensuring scientific freedom. It did not, however, address resource exploitation, nor did the area of its applicability extend to the high seas around Antarctica. Full membership in the treaty Is limited to consultative powers, that is, to the original twelve signatories (Argentina, Australia, Belgium, Chile, Franca, Japan, New Zealand, Norway, South Africa, ths U.S.S.R., the United Kingdom, and the United States) plus acceding nations while those nations are conducting substantial scientific activities in Antarctica (e.g., Poland, West Germany and East Germany). Other nations may accede to the treaty but do not have full (voting) membership. The consultative powers to the treaty do not own the krill around Antarctica, but they are able to build formidable barriers in the path of other nations attempting to harvest it. in 1976 the Food and Agriculture Organization and the United Nations Development Program proposed development of a food program for the Third World, which would be based on krill. This evolved into a $45 million program based on the Southern Ocean, which was anticipated to be of benefit to all countries. The plan met with resistance from Argentina, Australia, Chile, and the United Kingdom, which saw their power over Antarctica being usurped. Argentina insisted that the consultative powers unanimously approve any research conducted south of 60°S. The food program was cancelled. 43 In 1980 the consultative parties opened for signature a Convention on the Conservation of Antarctic Marine Living Resources. This Convention is applicable south of the Antarctic Convergence, and seeks to maintain the ecosystem in its present condition. Harvesting living marine resources is not prohibited but It is contingent on the following criteria being met. Harvesting must not decrease the size of a harvested population below that required for its stable recruitment; it must not jeopardize the ecological relationship between harvested, dependent and related populations; and it must minimize or prevent changes in the marine ecosystem when it is thought that those changes are not reversible within two or three decades. A Commission is established by the Convention to acquire and promote knowledge of the Antarctic marine ecosystem. The Commission will recommend limits on future harvesting, open and closed seasons, and areas where harvesting can take place. Recommendations will be based on the conservation—to include rational use—of Antarctic marine living resources. 44 EXPLOITATION OF KRILL Harvesting Krill fishing faces formidable obstacles. The climate of Antarctica and the Southern Ocean is more severe than V, 17 £3. 4 any other area of the world. Plankton has never been the basis of a fishery, although the Peruvian anchoveta industry, which developed In the 1950's is comparable In that It was based on very small fish which were processed into meal for livestock feed (mainly for chickens). 38 The season for krill fishing Is limited to December to March or April because the spread of the pack ice and winter conditions of Antarctica make fishing at other times impossible. 3 The tendency of krill to swarm makes fishing them practical, but these swarms are eccentric and unstable. The most practical methods of locating swarms are acoustically or visually, and remote sensing is also used, but the patchiness of the swarms does not allow continuous fishing. 3 Krill are harvested by trawling, either surface or midwater, depending on the position of the swarm. A very close mesh is necessary due to krill's small size. This, in turn, necessitates small trawls because of the large drag produced. 3 Processing Krill have to be processed within a very short period after they are harvested. Shortly after death, juice begins to exude from krill, blackening occurs, and they begin to develop a bad odor. The tissue and shell are extremely weak, and are easily damaged by pressure. U.S.S.R. fishery experts advise not to leave krill more than one hour at 10°C, or three to four hours at 0-7°C before processing. They also advise limiting piles of harvested krill to 30 centimeters in height. 45 There is also the problem of the krill's unappetizing appearance. The shell is either a brilliant red, rust, or pale yellow, 3 through which the green liver is clearly visible in the center. 45 Once the krill are on board ship they are stored in sea water. Deterioration commences immediately, and the ship's movements (especially during bad weather) accelerate this. When different sizes of krill are harvested processing is even more difficult, and automatic sorting is not technically feasible at present. It is also presently impossible to remove the krill's eyes, which does not enhance the appeal of the processed product. If the krill are peeled, the net weight is reduced by 85 to 90 percent of gross, although the value of the krill meat is increased. On average, only 28 percent of the krill harvested is retained in processing. 45 Processed whole krill is usually boiled and frozen, with or without shells. Krill can also bs dried after being frozen, but this causes blackening, oxidation of fat, and loss of flavor. Alternatively, paste is produced which is then mixed with cheese, butter, etc. A protein powder and porous protein concentrate can also be manufactured to be added to ground beef. 45 if krill is used for animal feed, the period between harvesting and processing may be increased to 12 hours. 46 The costs, however, make such livestock feed extremely expensive. The U.S.S.R. has fed krill to salmon and then harM T S Journal (Mi 117 vested the salmon, but this is also very expensive. 44 Chile has a plan to release salmon fry into the Southern Ocean, and then to harvest them upon their return. 40 The effect of the salmon on the Southern Ocean ecosystem however, is unknown, and it is thought that the krill would be too far south to be available to the salmon. 6 Marketability Krill is sold in many forms, depending upon the country harvesting it. The Japanese are accustomed to eating small shrimps, and whole krill were therefore well accepted there, whereas krill paste was not. The U.S.S.R. tried marketing canned krill, but this was a failure. 45 West Germany has plans to introduce krill as protein concentrate, and as artificial "crabmeat," 40 and a Swedish company is also marketing krill processed as "crabmeat." 46 Many problems in acceptability of krill products remain. Studies made by Norwegian scientists in 1979 showed that ground krill contains levels of fluoride which are seven to twenty-four times those permitted by the U.S. Food and Drug Administration. 4 6 This bar to marketing krill in the United States was eased in 1981, however. The U.S. Food and Drug Administration ruled that the sale of edible krill tail meat was permitted because fluoride content in krill which was eaten as a food, rather than as a food additive like fish protein concentrate, was low enough not to be injurious to human health. 2 The flavor and texture of krill has a high level of variability, and processed krill occasionally develops a metallic flavor combined with a bitter aftertaste. 46 Nevertheless, the krill Industry has attracted worldwide attention because krill is so abundant. Estimates of potential harvesting of between one hundred million and one billion metric tons per year have been suggested. 47 This contrasts with the present fishing industry totals of about seventy million metric tons per year. 6 To harvest large quantities of krill on a sustained basis will require increased knowledge of the interactions between the species of the Southern Ocean, and cooperation in pursuing long-term rather than short-term goals. 48 Any krill fishing industry necessarily has to be government sponsored because of the enormous costs involved. The Soviet Union has invested more money in krill fishing than any other nation, and Poland Is also heavily committed on a smaller scale. It is unlikely that the United States will participate in the near future for several reasons: Adequate food is already being produced; no demand for krill exists in the United States; the costs of maintaining a krill fleet are astronomical; and there are potential problems with recruiting crews to serve in the Antarctic. 3 7 CONCLUSION If harvesting and processing technology problems can be overcome, the potential exists for a very large krill industry. This has been the position adopted primarily 33 by the U.S.S.R., Poland, and Japan, but it leaves out an extremely important fact: Little is known about the precise role of krill in the Antarctic ecosystem. One fact, however, is indisputable: Krill are the cornerstone of all Antarctic life. To harvest krill without full knowledge of probable—and probably irreversible— impacts on the Antarctic is to jeopardize future use of Antarctic resources. REFERENCES 1. Small, G.L. 1971. The blue whale. Columbia University Press, New York. 2. Kay I or, J.D. and R.J. Learson. 1983. Krill and its utilization: A review. NOAA Technical Report NMFS SSRF-769. 3. Tetra Tech, Inc. 1978. The Antarctic krill resource: Prospects for commercial exploitation (report prepared for U.S. Dept. of State), pp. 237-380 In: Antarctic living marine resources negotiations, Hearing before the National Ocean Policy Study of the Committee on Commerce, Science, and Transportation. U.S. Senate, June 14, 1978. U.S. Government Printing Office, Washington, D.C. 4. Bakus, G.J., W. Garling and J.E. Buchanan. 1978. Antarctic krill: Ecology and commercial exploitation. Antarctic J. U.S. 13(4):135-136. 5. Committee to Evaluate Antarctic Marine Ecosystem Research. 1981. An evaluation of Antarctic marine ecosystem research. National Academy Press, Washington, D.C. 6. U.S. Dept, of State. 1978. Final environmental impact statement for a possible regime for conservation of Antarctic living marine resources. U.S. Government Printing Office, Washington, D.C. 7. George, R.Y. 1980. Pressure and temperature adaptations of Antarctic krill and common peracarid crustaceans. Antarctic J. U.S. 15(5):145-146. 8. Denys, C.J., T.P. Poleck and M.M. O'Leary. 1980. Biological studies of krill, austral summer 197980. Antarctic J. U.S. 15(5):146-147. 9. Ikeda, T., Dixon and Kirkwood. Laboratory observations of moulting, growth and maturation of the Antarctic krill (E. superba Dana) (unpublished paper). 10. McWhinnie, M.A., C.J. Denys, R. Parkin and K. Parkin. 1979. Biological investigation of Euphausia superba (krill). Antarctic J. U.S. 14(5):163-164. 11. McWhinnie, M.A., C.J. Denys, and D. Schenborn. 1976. Biology of krill (Euphausia superba) and other Antarctic invertebrates. Antarctic J. U.S. 11(2):55-58. 12. Ettershank, G. 1983. Age structure and cyclical annual size change in the Antarctic krill, Euphausia superba Dana Polar Biol. 2:189-195. 13. Ikeda, T. 1981. Metabolic activity of larval stages of Antarctic krill. Antarctic J. U.S. 16(5):161-162. 14. Ayala, F.J., J.W. Valentine and G.S. Zumwalt. 1974. Genetic variability in Antarctic krill. Antarctic J. U.S. 9(1):300-301. 15. McWhinnie, M.A. and C.J. Denys. 1978. Biological studies of Antarctic krill, austral summer, 19771978. Antarctic J. U.S. 13(4):133-135. 16. Macauiay, M.C. 1981. Distribution and abundance of krill in the Scotia Sea as observed acoustically, 1981. Antarctic J. U.S. 16(5): 166-167. 17. Brinton, E., E. Shulenberger, J. Wormuth and T. Antezana. 1981. Net sampling of plankton and krill in the Scotia Sea, January-March 1981. Antarctic J. U.S. 16(5):160-161. 18. Chen, C. 1968. The distribution of thecosomatous pteropods in relation to the Antarctic Convergence. Antarctic J. U.S. 3(5):155-157. 19. George, R.Y. 1981. Euphausiid larval distribution in the Scotia Sea, 1979-1980. Antarctic J. U.S. 16(5) :141 -142. 20. El-Sayed, S.Z. and I. Hampton. 1980. Phytoplankton/krill investigations in southwest Indian sector of the Southern Ocean. Antarctic J. U.S. 15(5): 143-144. 21. Paden, C.A., C.D. Hewes, A. Neori, O. HolrnHansen, E. Weaver, D.A. Kiefer and E. Sakshaug. 1981. Phytoplankton studies in the Scotia Sea. Antarctic J. U.S. 16(5):163-164. 22. El-Sayed, S.Z. and I. Hampton. 1981. Phytoplankton ecology and krill distribution in the Southern Ocean. Antarctic J. U.S. 16(5):138-139. 23. Beddington, J.R. and R.M. May. 1982. The harvesting of Interacting species in a natural ecosystem. Scientific American 247(5):62-69. 24. Attenborough, D. 1979. Life on earth. Little, Brown and Company, Boston. 25. Perry, R. 1973. The polar worlds. Taplinger Publishing Company, New York. 26. Parker, B.C. 1971, The case for conservation in Antarctica. Antarctic J. U.S. 6(1):50-53. 27. Fleischmann, K. 1979. The Antarctic O c e a n empty, but international. Impact of Science on Society 29:175-182. 28. El-Sayed, S.Z. and J.T. Turner. 1977. Productivity of the Antarctic and tropical/subtropical regions: A comparative study, pp. 463-503 In: M.J. Dunbar (ed.) Polar oceans. Arctic Institute of N. America, Calgary, Canada. 29. Hedgpeth, J.W. 1977. The Antarctic marine ecosystem, pp. 3-10 In: G.A. Llano (ed.) Adaptations within Antarctic ecosystems. Smithsonian Institution, Washington, D.C. 30. Pontecorvo, G. and M. Wilkinson. 1978. From cornucopia to scarcity: The current status of ocean resource use. Ocean Development and International Law J. 5:383-395. 31. Deacon, G.E.R. 1977. The Southern Ocean: History of exploration, pp. xv-xxxvii In: G.A. Liano (ed.) Adaptations within Antarctic ecosystems. Smithsonian Institution, Washington, D.C. 00118 v. 17 ii. 4 32. Scott, R.F. 1964. Scott's last expedition. The Folio Society, London, England. lands: Antarctica. Carlton, Australia. Melbourne University Press, 33. Russell, F.S. and M. Yonge (eds.). 1969. Advances in marine biology. Vol. 7. Academic Press, Inc., New York. 42. Alverson, D.L. 1980. Tug-of-war for the Antarctic krill. Ocean Development and International Law J. 8:171-181. 34. Pequegnat, W.E. 1958. Whales, plankton and man. Scientific American 198(1 ):84-90. 43. Barnes, J.N. 1979. The emerging Antarctic living resources convention. American Society of International Law—Proceedings 73:272-294. 35. Hardy, A. 1965. The krill—an ocean harvest of the future? New Scientist, July 1, 41-43. 36. Anonymous. 1968. Krill and chips? New Scientist, October 24,1968:205. 37. Croome, A. 1968. Surplus food from Antarctic waters. Science J. 4(10):37. 38. Potter, N. 1969. Economic potentials of the Antarctic. Antarctic J. U.S. 4(2):61-72. 39. Earthscan. 1977. The struggle for riches. Atlas, December 1977:21-23. Antarctica's 40. Exploitation of Antarctic resources. 1978. Hearing before Subcommittee on Arms Control, Oceans, and International Environment of the Committee on Foreign Relations. U.S. Senate, February 6, 1978. U.S. Government Printing Office, Washington, D.C. 41. Lovering, J.F. and J.R.V. Prescott. 1979. Last of M T S Journal 44. Conference on the Conservation of Antarctic Marine Living Resources, Canberra, 7-20 May 1980, Final Act; and Convention on the Conservation of Antarctic Marine Living Resources. 1981. In: International Legal Materials 20:837-859. 45. Suzuki, T. 1981. Fish and krill protein: Processing technology. Applied Science Publishers Ltd., London, England. 46. Brewster, B. 1982. Antarctica: Wilderness at risk. Friends of the Earth Books, San Francisco, California. 47. Joyner, C.C. 1981. The exclusive economic zone and Antarctica. Virginia J. International Law 21: 691-725. 48. May, R.M., J.R. Beddington, C.W. Clark, S.J. Holt and R.M. Laws. 1979. Management of multispecies fisheries. Science 205:267-277. Clfli 1 p 35