舟山近海凤鲚生长参数及资源量、持续渔获量分析
Estimation of biological parameter,biomass,sustaining yield for Coilia mystus in the offshore of Zhoushan
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摘要: 凤鲚是舟山渔场沿岸定置张网作业重要的渔获对象。本文根据2003年舟山近海定置张网调查数据整理的各月体长频率数据,应用F iSATⅡ软件进行分析,结果表明:生长参数K=1.01,极限体长L∞=196.88mm,自然死亡系数M=1.548,捕捞死亡系数F=1.512,总死亡系数Z=3.06,利用率E=49.41%,开捕体长Lc=85.76mm,种群数量为53.15×109ind,恒定资源量为2.37×104t。通过单位补充量产量、产值分析表明,若降低30%左右的捕捞努力量水平,能使产值最大化,可实现舟山近海凤鲚的可持续利用。Abstract: Based on the monthly length-frequency data of Coilia mystus obtained during 2003 in the offshore of Zhoushan, by applying the FiSAT Ⅱ(Version 1.2.2) and the result showed that the growth parameters of Von Bertalanffy growth equation was L∞=196.88mm, K=1.01, t0=-0.285. Natural Mortality Coefficient(M)was 1.548 from Pauly equation according to growth parameters and average water temperature. Total Mortality Coefficient (Z) was 3.06 that got from length-converted catch curve with biology datum. Fishing Mortality Coefficient (F) was ,1.512 and exploitation rate (E) was 49.41%. The Population was 53.15×109ind and Steady-state Biomass was 2.37×104t by using Length-Structured Virtual Population Analysis. Yield-per-recruit analysis and the value of yield-per-recruit analysis applying Beverton-Holt and Thompson-Bell model indicated, if the f-factor can be fell by 30%, than, we can get the most value to achieve the sustainable use of Coilia mystus.