Species composition and biomass of fishes by the data of bottom trawls in the northwestern Japan Sea in 1978-1990

Abstract

State of the demersal fish community in the northwestern Japan Sea in the period 1978-1990 is considered on the data of bottom trawl surveys. Mean total biomass of the demersal fish in the USSR economic zone in those times is estimated as 1.106. 106 t. The bulk of fish community was formed by the families Gadidae, Pleuronectidae, Clupeidae, Hexagrammidae, and Cottidae with summary portion 95.1 % by biomass and 84.8 % by number. The most abundant fish species were walleye pollock Theragra chalcogramma (44.8 % of the biomass), scale-eye plaice Acanthopsetta nadeshnyi (12.2 %), pacific herring Clupea pallasii (8.6 %), blackfin flounder Glyptocephalus stelleri (7.7 %), pacific cod Gadus macrocephalus (4.7 %), and arabesque greenling Pleurogrammus azonus (4.6 %), portions of other species didn’t exceed 3 %. The summary portion of flounders (23 species) was 28.0 %, by biomass. Scale-eye plaice dominated among them (on average 135.4. 103 t), other mass flounders were the blackfin flounder (84.8. 103 t), yellowstriped flounder Pseudopleuronectes herzensteini (29.0. 103 t), and yellowfin sole Limanda aspera (13.2. 103 t) though the latter species had dominated there in the 1930s.

Keywords

• biomass
• demersal fish
• walleye pollock
• scale-eye plaice
• pacific herring
• japan sea
• shelf
• continental slope