Prospects of the Utilization of Krill and Other Nonconventional Resources of the World Ocean
When animals of lower trophic levels are consumed by pelagic fishes, only 1–3% of the energy they contain is transformed into the new kinds of living matter which constitute useful fishery production. Thus the animals in the lower trophic levels, being more "economically profitable" and in...
Published in: | Journal of the Fisheries Research Board of Canada |
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Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
1973
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Subjects: | |
Online Access: | http://dx.doi.org/10.1139/f73-347 http://www.nrcresearchpress.com/doi/pdf/10.1139/f73-347 |
Summary: | When animals of lower trophic levels are consumed by pelagic fishes, only 1–3% of the energy they contain is transformed into the new kinds of living matter which constitute useful fishery production. Thus the animals in the lower trophic levels, being more "economically profitable" and in much greater abundance, offer strong possibilities for increasing commercial utilization of ocean resources. The most urgent task is to develop commercial fisheries among animals at the second trophic level, the zooplankton. The most promising of these are the crustaceans, especially the krill of the antarctic, Euphausia superba, which occupy areas of the ocean south of the antarctic convergence, in extremely high concentrations. The resource may be between 0.8 and 5 milliards of tons, yielding a total commercial catch as high as 25–50 million metric tons.Other crustaceans that may some day support commercial fisheries include other species of Euphausia, Munida, Pleuroncodes, and Calanus.The problems facing the development of fisheries for these animals are to devise efficient catching methods and methods of processing that preserve the nutrient value while providing acceptable products. Soviet work with krill has yielded promising results. A special midwater trawl has given catches of 10–20 tons/hr. The food value of krill is high. It can be made into protein paste for human consumption, or used as fodder. To make the paste the krill are pressed, the extracted juices treated with heat, and the coagulated paste is separated and frozen. Tests with animals fed this paste showed higher rates of growth than those fed with beef. Krill has been used in the production of "shrimp butter" and "melted cheese," the latter having been produced commercially since 1970. Other products show promise.Certain squids may become of great importance commercially, although some may be useful only as fodder because of their chemical composition. Some fish species at the third trophic level have dense stocks and offer promise. Among these are fish of ... |
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