The Atlantic tripletail(Lobotes surinamensis)is a high revenue-generating fish species predominantly caught by mechanized artisanal fishers community and the most available member of its family in Bangladesh.This is a...The Atlantic tripletail(Lobotes surinamensis)is a high revenue-generating fish species predominantly caught by mechanized artisanal fishers community and the most available member of its family in Bangladesh.This is a ground work of fish stock assessment study in the Bay of Bengal region to explore the life history parameters and associated biomass of this species,using three length-based approaches of TropFishR,the length-based Bayesian biomass estimation(LBB),and Froese’s length based indicators(LBIs).An almost homogenous body growth pattern(b=3.07;R^(2)=0.98)was observed in the length-weight relationship of tripletail.The life history parameters for tripletail,as determined by the von Bertalanffy Growth Function(VBGF)model,were L_(∞)=113.36 cm and k=0.51/a.The length converted catch curve(LCCC)yielded an estimation of the total mortality(Z=1.77/a),with the natural mortality estimated at(M=0.53/a)and the fishing mortality estimated at(F=1.24/a).But,the ratio of mortality(F/M=0.15)by LBB captured the non-fully exploited status of biomass(B/B_(MSY)=2.1).LBI analysis indicated that the tripletail fishery’s spawning stock biomass is greater than the target and limit reference points,indicating a healthy state of biomass.展开更多
The anadromous Hilsa shad(Tenualosa ilisha)fishery is the prime single species fishery of Bangladesh that driven by open access system which was selected for this study.Key purpose of this study was to assess the MSY(...The anadromous Hilsa shad(Tenualosa ilisha)fishery is the prime single species fishery of Bangladesh that driven by open access system which was selected for this study.Key purpose of this study was to assess the MSY(Maximum Sustainable Yield)in order to review the effectivity of the ongoing management policy of this fishery.For this reason,time series maritime or downstream catch-effort data of the Bay of Bengal were assembled from the Department of Fisheries,Bangladesh.MSY,CPUE and other population parameters were estimated through Surplus Production Models(SPMs)using computer software packages of CEDA,ASPIC and TropFishR.Assessed biological reference points of MSY from the best fitted CEDA package was 282,100 t(R^(2)=0.822)for the normal assumptions of the Schaefer and Pella-Tomlinson models.MSY values from the ASPIC packages(324,100 t and 263,500 t;for Fox and Schaefer model)and Schaefer model from TropFishR(345,486t)were larger than the catch in 2017(278,948 t).The values of F ratio(F/FMSY)for all SPMs were found less than 1 and B ratio(B/BMSY)were greater than 1 that clearly indicate the gradual upsurge of the Hilsa stock.Based on the above findings of BRPs,it also proves the effectivity of the current“Hilsa fishery management action plan”by the authorities.展开更多
基金Supported by the special research fund of Ocean University of China(No.201562030)。
文摘The Atlantic tripletail(Lobotes surinamensis)is a high revenue-generating fish species predominantly caught by mechanized artisanal fishers community and the most available member of its family in Bangladesh.This is a ground work of fish stock assessment study in the Bay of Bengal region to explore the life history parameters and associated biomass of this species,using three length-based approaches of TropFishR,the length-based Bayesian biomass estimation(LBB),and Froese’s length based indicators(LBIs).An almost homogenous body growth pattern(b=3.07;R^(2)=0.98)was observed in the length-weight relationship of tripletail.The life history parameters for tripletail,as determined by the von Bertalanffy Growth Function(VBGF)model,were L_(∞)=113.36 cm and k=0.51/a.The length converted catch curve(LCCC)yielded an estimation of the total mortality(Z=1.77/a),with the natural mortality estimated at(M=0.53/a)and the fishing mortality estimated at(F=1.24/a).But,the ratio of mortality(F/M=0.15)by LBB captured the non-fully exploited status of biomass(B/B_(MSY)=2.1).LBI analysis indicated that the tripletail fishery’s spawning stock biomass is greater than the target and limit reference points,indicating a healthy state of biomass.
基金This work is supported by the special research fund of Ocean University of China(201022001).
文摘The anadromous Hilsa shad(Tenualosa ilisha)fishery is the prime single species fishery of Bangladesh that driven by open access system which was selected for this study.Key purpose of this study was to assess the MSY(Maximum Sustainable Yield)in order to review the effectivity of the ongoing management policy of this fishery.For this reason,time series maritime or downstream catch-effort data of the Bay of Bengal were assembled from the Department of Fisheries,Bangladesh.MSY,CPUE and other population parameters were estimated through Surplus Production Models(SPMs)using computer software packages of CEDA,ASPIC and TropFishR.Assessed biological reference points of MSY from the best fitted CEDA package was 282,100 t(R^(2)=0.822)for the normal assumptions of the Schaefer and Pella-Tomlinson models.MSY values from the ASPIC packages(324,100 t and 263,500 t;for Fox and Schaefer model)and Schaefer model from TropFishR(345,486t)were larger than the catch in 2017(278,948 t).The values of F ratio(F/FMSY)for all SPMs were found less than 1 and B ratio(B/BMSY)were greater than 1 that clearly indicate the gradual upsurge of the Hilsa stock.Based on the above findings of BRPs,it also proves the effectivity of the current“Hilsa fishery management action plan”by the authorities.
