1983年夏季渤海上层鱼类生物量的估计

这项工作是渤海水产资源增殖研究中的一个组成部分。1982年4月至1983年5月对该海区底层所进行的鱼类调查结束后,接着于6月和7月开展了上层的鱼类调查。调查工具为185马力双船上层拖网。网口周长为800目,目大100毫米。网囊部为20毫米目。拖网时,两船间距平均为94.5米,网袖间距平均为17.8米,

FISH BIOMASS ESTIMATES AT THE UPPER LAYER OF THE BOHAI SEA IN SUMMER, 1983

Samples of fish for estimating their biomass were collected from more than 50 stations throughout the whole Bohai Sea by the epipelagic pair trawlers with a towing speed of 3.5 knots. The height of mouth of the trawl was 8m. Primary results estimated by traditional area method of the survey are as follows: The mean catch per unit effort was 26.9 and 11.9 kg/h, the biomass density was 0.311 and 0.137 ton/km², the total biomass was 24,880 and 10,960 ton for June and July respectively. Forty nine fish species were collected during the two months in 1983. Engraulis japonic a is the most dominant species, accounting for three-fourths for June and One-third for July of the total catch by weight.