Distribution of zooplankton in Ommastrephes batrami fishing ground of the North Pacific Ocean and its relationship with the fishing ground

The survey on ecological environment and squid resources was carried out in the fishing ground of Ommastrephes batrami in the North Pacific Ocean( 152bE- 171bW, 39b- 42bN) from June to August, 2001. The results showed that average biomass of zooplankton was 92. 12mg#m- 3( 0. 81- 1035. 68 mg#m- 3) in the all water area, 113. 51mg#m- 3 in the middle water area ( 160b- 180bE, 39b- 42bN) and west longitude water area ( 170b- 178bW, 40b- 41bN) and 22. 89mg#m - 3 in the west water area ( 152b- 157bE, 41b- 43bN) ; the zooplankton abundance was mainly composed of Copepoda ( 42. 11% ) , followed by Thaliacea ( 30. 91%) ; Eucalanus pseudattenuatus, Calanus pacif ica and Dolioletta gegenbauri were main dominant species. Crustacean distribution also corresponded well with the f ishing ground, the centre of which was just located in or near the high abundance area of crustacean ( 50- 100 ind#m- 3) and high biomass area of zooplankton ( 250- 500mg# m- 3) . The distribution of Cephalopoda larva is also in or near the high abundance area of Euphausiacea and Amphipoda.