A Review of the World Resources of Mesopelagic Fish

A Review of the World Resources of Mesopelagic Fish PDF

Author: J. Gjøsaeter

Publisher: Food & Agriculture Org.

Published: 1980

Total Pages: 164

ISBN-13: 9789251009246

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A fish species can be called mesopelagic if it spends the day in the mesopelagic zone. The mesopelagic zone has been defined in different ways based on depth, temperature and light regimes. For the present purpose, depth seems to be the best criterion and mesopelagic fish can thus be defined as species generally spending the day at depths between approximately 200 and 1 000 m. Generally they perform a diel migration, coming to the upper 200 m or even to the surface during the night. The present report briefly reviews the systematics ecology and life history of important groups of mesopelagic fish. Further, some methods used for abundance estimation of these fish are described and discussed. The bulk of the report reviews the present knowledge of abundance and species composition of mesopelagic fish in each of the FAO statistical areas. Although the data in most cases are few, an attempt has been made to give tentative estimates of the biomass and production in the various areas. When available, information on the life history of the most important species in each area is also given.

Coastal Upwelling Its Sediment Record

Coastal Upwelling Its Sediment Record PDF

Author: Erwin Suess

Publisher: Springer Science & Business Media

Published: 2013-03-09

Total Pages: 599

ISBN-13: 1461566517

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NATO Advanced Research Institutes are designed to explore unre solved problems. By focusing complementary expertise from various disciplines onto one unifying theme, they approach old problems in new ways. In line with this goal of the NATO Science Committee, and with substantial support from the u.s. Office of Naval Research and the Seabed Assessment Program of the U. S. National Science Founda tion, such a Research Institute on the theme of Coastal Upwelling and Its Sediment Record was held september 1-4, 1981, in Vilamoura, Portugal. The theme implies a modification of uniformitarian thinking in earth science. Expectations were directed not so much towards find ing the key to the past as towards exploring the limits of interpret ing the past based on present upwelling oceanography. Coastal up welling and its imprint on sediments are particularly well-suited for such a scientific inquiry. The oceanic processes and conditions characteristic of upwelling are well understood and are a well packaged representation of ocean science that are familiar to geolo gists, just as the magnitude of bioproduction and sedimentation in upwelling regimes --among other biological and geological processes- have made oceanographers realize that the bottom has a feedback role for their models.

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