黄海南部小黄鱼生长、死亡和最适开捕体长

Growth,mortality and optimum catchable size of small yellow croaker (Larimichthys polyactis Bleeker) in the Southern Yellow Sea

根据2008-2009年在黄海南部海域底拖网采集的小黄鱼[Larimichthys polyactis(Bleeker,1877)]样本的生物学资料,应用FiSAT软件对小黄鱼的生长、死亡参数进行估算,通过Beverton-Holt模型评价小黄鱼资源的利用状况,并与临界体长、拐点体长等进行比较,以确定最适开捕体长。结果显示:(1)小黄鱼的体长(L)和体质量(W)关系式为W=0.0268×L2.814。(2)应用FiSAT软件拟合的von Bertalanffy生长方程参数为L=27cm,k=0.45a-1,t0=-0.47a(;3)总死亡系数Z=2.40,自然死亡系数M=0.77,捕捞死亡系数F=1.63,开发率E=0.68。(4)在现行的捕捞死亡系数F=1.63下,Yw/R达到最大值时开捕年龄和开捕体长分别为1.41a和15.42cm;拐点年龄和体长分别为1.83a和17.41cm;临界年龄和体长分别为1.70a和16.82cm。现阶段小黄鱼资源已处于过度开发状态,综合考虑渔民利益和资源修复需要,建议黄海南部小黄鱼的最适开捕规格定为体长14.83cm。

Based on the biological data collected from the trawl fishery survey in the southern Yellow Sea from 2008 to 2009,growth and mortality parameters of small yellow croaker（ Larimichthys polyactis（ Bleeker,1877）） were estimated by the FiSAT II software,and status of stock and optimal first capture size were assessed by Beverton-Holt model. Optimum catchable size was determined by comparing the critical size and the length of point of inflection. The result showed that：（1） the relationship between body length and body weight can be expressed as W = 0.0268× L2.814（;2） Growth parameters can be described by the von Bertalanffy growth equation,the parameters were estimated to be L∞ = 27.00 cm ,k = 0.45 a-1 and t0 = - 0.47 a;（3） Mortality coefficients were estimated to be Z = 2.40,M = 0.77, F = 1.63 and exploration rate E = 0.68;（4） Under the actual fishing mortality coefficient F = 1.63,Yw/R can get maximum when the first capture age and size were 1.41a and 15.42 cm. It was suggested that the optimum catchable size of small yellow croaker in the Southern Yellow Sea was 14.83 cm.