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