Geographical and biological characteristics of the net zooplankton in the southwestern part of the Sea of Okhotsk during 1987–1996

• Main Author: Irina Y. Bragina
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Okhotsk; okhotsk sea
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.359.9336; http://www.pices.int/publications/scientific_reports/Report12/bragina_f.pdf

During 1987–1996 zooplankton studies were conducted by standard stations in the neritic, shelf and continental slope zones in the southwestern part of the Okhotsk Sea. Zooplankton species were collected by Juday net by total catch from 100 m up to the surface. The comparative zooplankton species analysis included 88 forms from 5 subareas and one transect that covered different geographical conditions. Defined: (1) species determination, biomass dynamics, distribution and possible driving environmental factors of the net zooplankton biomass, (2) zooplankton ecological characteristics, (3) taxonomic group predominance in biomass (Chaetognatha, Euphausiidae, Copepoda) and (4) proportion of the predator/prey ratio. Regions were determined where conditions for the fish feeding was estimated as the richest. Level biomass range varied from 203–2055 mg/m 3. The most productive area has been estimated to be east off Terpenia Peninsula. The role of Chaetognatha predominance (up to 75 % in plankton biomass) was determined as negative in feeding accessibility as well for the fish juvenile survival. The high zooplankton biomass level corresponded to low-temperature years.