Supplements to the generalized quantitative assessments of benthic macrofauna in the Far-Eastern Seas and adjacent waters of the Pacific Ocean. Report 2. Regional and bathymetric features of biomass and density of its distribution for fish and some groups of invertebrates

Abstract

Data on mean annual biomass (t) of the bottom macrofauna groups and main species in the Far-Eastern Seas and adjacent waters of the Pacific Ocean, by bathymetric ranges, and on density of their distribution (t/km 2 ) are summarized. The average density of distribution for bottom and demersal fish varies from 5.8 to 26.9 t/km 2 in the range 0-200 m, from 8.6 to 26.9 t/km 2 in the range 200-500 m, from 3.6 to 14.7 t/km 2 in the range 500-1000 m, and from 3.4 to 15.7 t/km 2 in the range 1000-2000 m. The average density for bottom invertebrates varies within 4.0-12.6, 4.7-19.6, 1.7-10.2, and 0.6-3.0 t/km 2 , respectively. The density usually increases in the transitional zone between the continental shelf and a slope (200-500 m). Aggregations of total macrofauna are the densest in this bathymetric range and reach 32.3 t/km 2 in the Bering Sea, 15.2 t/km 2 in the Japan Sea, and 41.4 t/km 2 in the Pacific waters at Kuril Islands. However, the concentrations in this zone in the Okhotsk Sea (maximum 13.3 t/km 2 ) and the Pacific waters at Kamchatka (31.5 t/km 2 ) are lower than that ones on the continental shelf.