辽东湾黄鲫生长、死亡和单位补充量渔获量研究

Growth,mortality and yield per recruitment of Setipinna taty in the Liaodong Bay

为了解辽东湾黄鲫(Setipinna taty)的生物学特征和资源现状,根据2019年6、7、9月与2020年5、8、10月对辽东湾海域的底拖网调查数据,应用ELEFANⅠ方法与体长变缓渔获曲线法估算黄鲫生长参数与总死亡系数,并利用Beverton-Holt单位补充量渔获量模型评估辽东湾黄鲫资源状况,同时结合拐点年龄与临界年龄确立其最适开捕规格。结果表明:黄鲫渔获群体体长范围为4.0~16.9 cm;体质量范围为0.52~43.30 g;体长-体质量关系W=0.005674×L^(3.1614)(R^(2)=0.96888,n=1716);Von Bertalanffy生长方程参数:渐近体长(L_(∞))、生长系数(K)和理论初始年龄(t_(0))分别为23.8 cm、0.57和-0.30 a,生长表现指数Φ为2.51;总死亡系数Z为2.90±0.47,自然死亡系数M和捕捞死亡系数F分别为1.10和1.80±0.47,开发率E为0.62,黄鲫处于过度开发状态;拐点年龄t_(tp)为1.71 a,拐点体长为16.3 cm,临界年龄T_(c)=1.39 a,临界体长为14.7 cm。综合考虑补充群体及资源可持续性,建议将开捕体长设置在14.8 cm。研究结果可为黄鲫资源开发以及辽东湾渔业生态系统研究提供参考。

Liaodong Bay is an important fishery water area with superior geographical conditions and numerous tidal beaches.Many rivers such as Liao River,Daling River and Xiaoling River flow into the Liaodong Bay.A large number of nutrients enter into the bay along with the runoff.Therefore,Liaodong Bay is the spawning ground,fattening ground and habitat of many important fishery species.Setipinna taty is an important fishery species in the Liadong Bay.It is widely distributed in all seas of China from the south to the north,usually inhabiting in the sea area with mixed water and sediment bottom.It has the behaviour of seasonal north-south migration,swimming to the Yellow Sea and Bohai Sea to breed from April to June,leaving the spawning and feeding grounds to the south to overwinter from November to December every year.It mainly feeds on shrimp and copepods,and is also an important food for large and medium-sized fish,occupying an important position in the food web and ecosystem of the Liaodong Bay.In the 1970s,the annual yield of Setipinna taty in China was about 40000 t,while that in Liaodong Bay was about 10000 t.Setipinna Taty resource was relatively stable,but with the growth of fishing effort,it declined in the early 21st century.Therefore,it is very important to study the biological characteristics of growth,mortality and resources of Setipinna taty.Based on data collected by bottom trawling survey in the Liaodong Bay in 2019 and 2020,the growth parameters of Setipinna taty were estimated by ELEFANⅠ,and the total mortality coefficient was estimated by length-converted catch curve.In order to provide a basic reference for the exploitation of the stock resource of Setipinna taty and study of fishery ecosystem in the Liaodong Bay,Beverton-Holt yield per recruitment model was used to evaluate the stock resource of Setipinna taty in the Liaodong Bay,the optimum catchable size was determined by comparing the critical size and the length of inflection point.The results showed that the body length of Setipinna taty ranged from 4.0 to 16.9 cm and the dominant body length ranged from 6.0 to 8.9 cm and 11.0 to 12.9 cm and the body weight range of 0.52-43.30 g and the dominant body weight of 0.00-4.99 g;the body length-weight relationship could be described with equation W=0.005674×10~(-5)L~(3.1614)(R^(2)=0.9688,n=1716).The parameters L_(∞),K and t_(0) of Von Bertalanffy formula estimated were 23.8 cm,0.57 and-0.30 a.The growth performance indexΦwas 2.51.Growth performance indexΦis an indicator to measure the growth performance of fish.The total mortality coefficient Z was 2.90±0.47,the natural mortality coefficient M and fishing mortality coefficient F were 1.10 and 1.80±0.47 respectively,and the exploitation rate E was 0.62,indicating the stock of Setipinna taty at an over exploitation state.The age and size of point inflection were 1.71 a and 16.3 cm respectively,and the critical age and size were 1.39 a and 14.7 cm respectively.Considering the sustainability of the supplementary population and resources,it is recommended to set the optimum catchable size of Setipinna taty in the Liaodong Bay at 14.8 cm.