山东近海口虾蛄单位补充量渔获量评估

为完善口虾蛄的基础生物学资料,并为口虾蛄资源的管理提供科学指导和理论依据,本研究根据2016至2017年山东近海渔业资源底拖网调查获得的口虾蛄体长、体质量数据,估算了口虾蛄的生长、死亡参数,构建了基于体长结构的单位补充量渔获量(YPR)模型,研究口虾蛄的资源动态和管理策略。采集调查口虾蛄样品共5028尾,体长—体质量关系的表达式为W=0.0145L2.88,为负异速生长;使用ELEFAN方法估算出口虾蛄的渐进体长L∞为19.87 cm,生长速率K为0.62 a?1。口虾蛄的生长表现出明显的季节性变化规律,生长参数的季节振幅C为0.76,10月份生长最快,4月份生长最慢。通过体长转换的渔获曲线估算出口虾蛄的总死亡系数Z为3.24 a?1,根据不同方法估算自然死亡系数M的范围为0.75~1.27 a?1,捕捞死亡系数F的估算范围为1.96~2.49 a?1,开发率的均值为0.67。YPR模型结果显示,随着F增大,YPR值呈现先上升后下降的趋势,生物学参考点F0.1和Fmax的值分别为0.92a?1和1.88a?1。口虾蛄资源处于过度开发的状态,应降低捕捞压力,同时调整开捕体长,以维持口虾蛄渔业资源量和渔获量。

Yield per recruitment evaluation of Oratosquilla oratoria in coastal waters of Shandong

In order to complement the basic biological information of Oratosquilla oratoria and provide managers with scientific guidance and theoretical basis,based on the size composition data of O.oratoria obtained from fishery independent surveys from 2016 to 2017 in coastal waters of Shandong Peninsula,this study estimated the growth and mortality parameters of O.oratoria.A length-structure yield per recruitment model was used to assess the population dynamics and management strategy of the species.A total of 5028 individuals were caught,from which the length-weight relationship was derived as W=0.0145L2.88,showing a negative allometric growth pattern.Asymptotic body length and growth coefficient estimated by ELEFAN were L∞=19.87 cm and K=0.62 a?1,respectively.The growth rate of O.oratoria showed remarkable seasonal oscillation,the highest in October and the lowest in April,and the amplitude of the seasonal oscillation(C)was 0.76.The total mortality(Z)estimated by length-converted catch curve was 3.24 a?1,and the natural mortality(M)estimated by several estimators ranged from 0.75 to 1.27 a?1.Accordingly,the fishing mortality(F)ranged from 1.96 to 2.49 a?1,and the mean exploitation rate was 0.67.Results of YPR model showed that with the F increasing,YPR tended to increase at first,and then decrease.Biological reference points F0.1 and Fmax were 0.92 a?1 and 1.88 a?1,respectively.This study shows that O.oratoria stock is over-exploited.In order to maintain stock and fishery of O.oratoria,fishing pressure needs to be reduced and length at first capture should be increased.