长江口凤鲚资源变动及最大持续产量研究

Studies on resource change and MSY of Coilia mystus in the Yangtze River estuary

对1997-2003年凤鲚生物学、资源量及最大持续产量进行了研究。汛期风鲚平均全长151mm,平均体重14.2g;全长和体重呈幂函数相关,拟合方程为W=0.036×L2.1874,丰满度系数为0.421。绝对怀卵量变幅为4677～24159粒,相对怀卵量变幅为859～1072粒/g体重,成熟卵卵径平均为0.67mm。同期凤鲚年均捕捞量为952.46t,年均汛末瞬时资源量41.57t。应用schaefer模式估算最大持续产量为1417.4t。与历史资料比较,在过度捕捞和水域污染的影响下,凤鲚资源量急剧下降,此不利情况应得到重视。

Studies on biological characteristics,resources and MSY of Coilia mystus in the Changjiang estuary were carried out during 1997-2003. Average value of total-length and body-weight were 151mm and 14.2g. Correlation equation between total-length and body-weight of Coilia mystus might be expressed as W=0.036×L^(2.1874) and the fullness coefficient was 0.421. The amplitude of changes about absolute fecundity and relative fecundity were 4677-24159 eggs and 859-1072 eggs/g body weight respectively, Average diameter of mature egg was (0.67)mm. In the corresponding period,average catch was 952.46 tons and average surplus-resource at the end of fishing season was 41.57 tons. MSY evaluated by model of schaefer was 1417.4 tons. Compared with the historical data,resource of Coilia mystus had dropped sharply under the effect of overharvesting and water pollution, more attention should be paid to the disadvantageous complexion.