Zooplankton Studies at Ocean Weather Station "P" in the Northeast Pacific Ocean
Concentrations of zooplankton observed at Station "P" (50°N.L., 145°W.L.,) are less than those in the Northwest Pacific, the Bering Sea, British Columbia coastal waters and the Labrador Sea; about equal to those at Station "M" in the Norwegian Sea; and greater than those in the c...
| Published in: | Journal of the Fisheries Research Board of Canada |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1961
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/f61-001 http://www.nrcresearchpress.com/doi/pdf/10.1139/f61-001 |
| Summary: | Concentrations of zooplankton observed at Station "P" (50°N.L., 145°W.L.,) are less than those in the Northwest Pacific, the Bering Sea, British Columbia coastal waters and the Labrador Sea; about equal to those at Station "M" in the Norwegian Sea; and greater than those in the central Equatorial Pacific and the Sargasso Sea. Zooplankton abundance at Station "P" appears representative of that in a wide area of the central Gulf of Alaska. A vertical distribution of zooplankton characterized by maxima of concentration from 0–100 metres and from 200–500 m was observed both day and night and in all seasons. Daily means of concentration of surface zooplankton ranged from about 20 g per 1000 m 3 in winter to about 150 in summer. A small autumn maximum was observed. A similar seasonal cycle of abundance occurred down to depths of about 200 m. Below 200 m the amplitude of the seasonal cycle tended to decrease with depth. Vertical hauls captured mainly copepods all year round. Horizontal surface tows revealed a marked seasonal cycle in taxonomic composition. A pronounced diurnal variation in the concentration of surface zooplankton was observed and showed the major features of typical diurnal vertical migration. Night catches of vertical hauls exceeded day catches. |
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