东海鲐鱼资源和渔场时空分布特征的研究

Tempo-Spatial Characteristic Analysis of the Mackerel Resource and Its Fishing Ground in the East China Sea

根据1998~2003年我国东海大型灯光围网企业生产统计数据,利用灰色关联评价等数理方法对东海鲐鱼资源和渔场的时空分布特征进行了分析。结果表明,主要作业渔场在经度上分布无差异,85%以上产量分布在122°E^124°E海域,而作业渔场在纬度上分布差异明显,但主要分布在26°N^28°N和30°N^31°N海域。较高平均网次产量(20 t/net)的海域主要集中在123°E^124°E、26°N^28°N及123°E^124°E、30°N^31°N海域。灰色关联度表明,6年间,以1999年鲐鱼资源状况最好,其次为2002年,2000年最差,1998年、2003年和2001年处于中间水平。分析认为,2000年鲐鱼资源最差可能与1999年捕捞产量过高造成亲鱼量急剧下降、夏季渔场水温偏低和鲐鱼资源的周期性波动等因素有关。

Based on the catch data of Chinese large lamp purse seines in the East China Sea from 1998 to 2003, the tempo-spatial distributions of the mackerel resource and fishing grounds in the East China Sea were analyzed using the methods of correlation analysis and grey relationship analysis. The results indicated that the distribution of main fishing ground had no significant difference in the longitudinal direction and 85% of the catch was distributed in 122°-124°E. The fishing grounds, however, had a remarkable difference in the latitu- dinal direction and they were mainly located in the waters of 26°-28°N and 30°-31°N. Higher mean catches per net （20 t/net） came from the waters of 26°-28°N, 123°-124°E and 30°-31°N, 123°-124°E. The results obtained by grey relationship analysis indicated that the mackerel resource status in 1999 was the best, followed by 2002, 1998, 2003 and 2001, and the resources in 2000 were at the lowest level. The analysis suggested that the lowest catch level in 2000 was related to sharp decease of parent fishes that resulted from the higher catch in 1999, lower water temperature in the fishing ground in summer and periodical fluctuation of the mackerel resource.