北太平洋公海秋刀鱼渔场初步分析

根据2004年7~11月“中远渔1号”调查船北太平洋公海秋刀鱼渔场探捕调查的生产情况,对秋刀鱼渔场进行分析。结果发现:①秋刀鱼渔场可根据渔场位置分为北部渔场和南部渔场,北部渔场范围为44°~45°N、156°~158°E,南部渔场范围为41°~42°N、150°~151°E,南部渔场的分布范围小于北部渔场。②秋刀鱼的生产以11月份生产最好,平均日产量达22.7t,其中最高日产量为60.42t;8月份的秋刀鱼生产最差,平均日产量为2.95t,与2003年的12.05t反差较大,主要是由于受到渔场环境因子变化的影响,鱼发位置偏至俄罗斯专属经济区内的缘故。③秋刀鱼舷提网作业平均日放网次数达7.6次,最高1天放网次数达到16次,而最高网次产量为11.05t。④秋刀鱼渔获组成以中小型鱼为主,占80%以上,除7月份渔获中特大型秋刀鱼占有较大比例外,其余月份很少有特大级秋刀鱼。⑤在相近的渔场位置,秋刀鱼个体随着生产月份的推迟,鱼体呈变小的趋势。

Preliminary analysis on the fishing grounds of Cololabis saira in the North Pacific Ocean

Based on the production database of vessel" Zhongyuanyu 1"in the North Pacific Ocean during July-November 2004, the fishing grounds of Cololabis saira were analyzed. The results were summarized as follows: (1) According to the position the above-mentioned fishing grounds can be divided into the north and the south fishing grounds, the north grounds are around 44°-45°N,156°-158°E,and the south around 41°-42°N,150°-151°E, with the former being larger than the latter in the scope of distribution; (2) The maximum catch was in November, the average production per day was 22.7 t,and the highest production per day was 60.42 t. The minimum catch was the worst in August, with an average production of 29.5t per day, and in contrast with in August 2003, the average day production was 12.05t. The production varied greatly on account of the change of environmental factors in the fishing grounds ,and the central fishing grounds were on the Russian EEZ; (3)The average day setting number of stick-held net fishery was 7.6,with the highest day setting number of 16 and the highest production per net of 10.05 t; (4) The composition of catch was mainly medium-sized and small-sized fishes, which accounted for 80% of the total catch.There were few extra large-sized Cololabis saira except July; (5)The longer the fishing month, the smaller the size of Cololabis saira on the nearby fishing grounds.