海州湾及邻近海域大泷六线鱼的生长、死亡和最适开捕体长研究

Growth,Mortality and Optimum Catchable Size of Hexagrammos otakii in Haizhou Bay and Its Adjacent Waters

根据2011年海州湾及邻近海域的底拖网调查资料,对大泷六线鱼（Hexagrammos otakii）的群体结构、体长-体重关系、生长、死亡和资源利用状况进行初步研究。结果表明：大泷六线鱼渔获群体体长范围为44-292mm,优势体长组为54-74mm,平均体长为88mm;体重范围为0.35-574.3g,优势体重组为〈10g,平均体重为17.94g;体长-体重关系为W=4.23×10-6 L3.31（R2=0.978 6,n=1 514）。应用FiSATⅡ软件中的ELEFANⅠ方法估算的von Bertalanffy生长方程参数L∞、K和t0分别为328mm、0.36a-1和-0.43a;应用FiSAT软件中变换体长渔获曲线法求得总死亡系数Z为2.06,自然死亡系数M和捕捞死亡系数F分别为0.62和1.44,开发率E为0.70。Beverton-Holt单位补充量渔获量模型分析表明,在现行捕捞死亡系数F=1.44、YW/R取最大值时对应的开捕年龄为1.83a。现阶段大泷六线鱼资源已处于过度开发状态,考虑拐点年龄、临界年龄、繁殖和经济效益等综合因素,建议将海州湾大泷六线鱼最适开捕规格定为体长191mm。

Based on the data collected by bottom trawling in Haizhou Bay and its adjacent waters in 2011,the population structure,length-weight relationship,growth and mortality of Hexagrammos otakii were analyzed.The results indicated that the standard length ranged from 44 to 292mm with an average of 88 mm and a dominant range of 54-74mm,and the body weight ranged from 0.35 to 574.3g with an average of 17.94 g and a dominant range of〈10g.The length-weight relationship can be described with equation W=4.23×10-6 L3.31（R2=0.978 6,n=1 514）.The growth parameters of von Bertalanffy formula estimated by ELEFAN I of FiSAT II were 328 mm（L∞）,0.36a-1（K）and-0.43a（t0）.The total mortality coefficient Zestimated referring to length-converted catch curve was 2.06 while the natural mortality M and fishing mortality F were 0.62 and 1.44,respectively and the exploitation rate was 0.70.Beverton-Holt yield per recruitment model simulation showed that for the current fishing mortality,the maximumYW/Rcould be obtained when the age at first capture was delayed to 1.83 a.Considering flexion age,critical age,recruitment and economic interest,it was suggested that standard length of 191 mm was the optimum catchable size of Hexagrammos otakii in Haizhou Bay and its adjacent waters.