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1.
黄鳍金枪鱼(Thunnus albacares)是全球远洋渔业的重要目标鱼种,要实现有效的管理,对其进行科学的资源评估是必不可少的。本文以大西洋黄鳍金枪鱼为研究对象,根据国际大西洋金枪鱼养护委员会的渔获量和单位捕捞努力量渔获量数据,使用贝叶斯状态空间模型进行资源评估,并探讨不同剩余产量函数和单位捕捞努力量渔获量数据对评估的影响。结果表明,使用美国、委内瑞拉、日本和中国台北4个船队的单位捕捞努力量渔获量数据及Fox剩余产量函数时模型拟合效果最佳。关键参数环境容纳量和内禀增长率的估计中值和95%置信区间分别为178 (140,229)×104 t和0.210(0.159,0.274);当前资源量为72.5×104 t,最大可持续产量为13.7×104 t时,种群既没有遭受资源型过度捕捞,也没有捕捞型过度捕捞发生。敏感性分析表明,当渔获量数据存在误报率(70%、80%、90%、110%、120%和130%)时,生物量的评估结果偏高,而捕捞死亡率的结果偏低,但种群均处于健康状态;预测分析显示,当总允许可捕量设为11×104 t时,资源在2024年前仍基本保持健康状态。本研究与国际大西洋金枪鱼养护委员会现有的评估结果基本一致,且模型较稳健,可以为管理决策提供建议。根据模型结果,建议总允许可捕量为11×104 t或更低,以使资源达到可持续开发水平。  相似文献   

2.
浅谈南海区渔业资源保护   总被引:2,自引:1,他引:1  
1999年南海区开始实施伏季休渔制度,然而休渔效果并不持久,开捕后的头一二个月渔船单产明显提高,一二个月过后又恢复了过去的低产状况。现在的南海区渔业资源状况如何,今后要如何管理?这里试想从分析渔业资源变化情况人手,结合南海区实际,提出资源保护措施,供渔业主管部门和渔业生产者参考。 一、渔业资源的利用及变化情况 南海归我国管辖的面积约216万平方千米,其中渔场约156万平方千米。建国后,南海区海洋渔业资源的开发利用大抵可分为4个阶段,即从初期开发阶段转向充分开发阶段再转向过度开发阶段进而进入衰退阶段…  相似文献   

3.
限额捕捞试点工作逐步展开,预示着我国海洋渔业管理进入全面有序的管理时代。文章根据2008—2017年南海北部渔港渔业生产抽样调查数据,统计出南海北部金线鱼的产量主要来自刺网,占累计总产量的72.90%。剩余产量模型分析认为南海北部金线鱼的最大可持续产量在168 632.99~31 0518.85 t,平均为251 765.59 t。2017年实施最严格的休渔制度后,当年的捕捞努力量投入和渔业产量均未超过最适值,当前总可捕量可设为158 515 t。文章研究结果可为该鱼种限额捕捞政策实施提供参考。  相似文献   

4.
近几十年来,黄海渔业资源的开发利用得到了飞速发展。作为重要的海水养殖以及海洋捕捞区域,黄海海洋生态系统为全国提供了丰富的海产品。本研究首次采用海洋供给服务评估方法研究黄海区域养殖生产和捕捞生产的物质量及价值量变化情况,结果表明:1990—2015年,黄海区域海水养殖物质量和价值量持续上升,2015年养殖物质量(883.1万t)比1990年(103.6万t)上升了752.4%,价值量则从130.1亿元上升至1 834.4亿元。与此同时,海洋捕捞物质量和价值量则呈现先上升后下降的趋势,在2000年达到顶峰(530.7万t,2 772.3亿元)后均有所下降。海水养殖价值量百分比组成变化十分显著,由最初的贝类和虾蟹类为主变为贝类(45.8%)和其他类(32.8%)为主。海洋捕捞价值量中其他类和头足类的比例也在不断增加,2015年增至24.9%,仅次于鱼类的捕捞价值量。黄海区域渔业利用变化情况与全球气候改变、近岸水域环境受污染严重以及各类养殖技术快速发展等密不可分。本研究期望通过海洋供给服务评估分析为黄海区域渔业资源利用管理以及可持续发展提供一定的科学基础。  相似文献   

5.
蓝色增长研究进展及在近海渔业资源   总被引:2,自引:0,他引:2  
渔业资源是一种重要的可再生海洋资源,是人类食物和营养的重要来源之一,为人类社会和经济发展做出重大贡献。目前,我国近海渔业资源处于过度捕捞的状态,传统经济种类资源出现衰退。为了渔业资源可持续利用和社会经济发展,必须采取行之有效的管理措施,以遏制过度捕捞。蓝色增长作为渔业资源可持续利用和社会经济共同发展与环境保护的新理念,为协调生态、经济和社会目标提供了一种新的思路。本文通过介绍蓝色增长等基本理论,归纳蓝色增长的研究现状及应用情况,并为我国渔业资源实现蓝色增长提出未来的研究方向,旨在为我国近海渔业资源可持续利用和近海生态文明建设提供参考。  相似文献   

6.
中国近海大多数渔业都属于数据有限渔业,用对数据要求较高的复杂模型无法对这些渔业资源做出有效评估,因此用数据有限评估模型评估渔业资源的研究具有重要意义。本文使用经典剩余产量模型(CEDA和ASPIC)和两种新型有限数据评估模型(贝叶斯Schaefer剩余产量模型(BSM)和蒙特卡洛MSY估算模型(CMSY)),评估了黄渤海鳀鱼(Engraulis japonicus)、东海带鱼(Trichiurus lepturus)和南海金线鱼(Nemipterus virgatus)这三种重要渔业资源的生物学参考点和资源现状。研究表明:黄渤海鳀鱼MSY估计值为80×10~4~83×10~4 t,生物学参考点F/F_(MSY)估计值小于1.0而B/B_(MSY)略小于1.0,表明这种渔业捕捞强度适中但资源尚未得到完全恢复。东海带鱼MSY估计值为58×10~4~64×10~4 t,F/F_(MSY)估计值大于1.0而B/B_(MSY)估计值小于1.0,表明这种渔业存在过度捕捞且资源已经衰退。南海金线鱼MSY为30×10~4~32×10~4 t,F/F_(MSY)估计值大于1.0而B/B_(MSY)估计值小于1.0,表明这种渔业存在过度捕捞且资源已经衰退。以上4种模型均可适用于中国近海数据有限的渔业资源,但两种经典剩余产量模型对三种渔业数据的拟合不够稳定(相关系数R~2波动较大),因此取BSM和CMSY模型的评估结果作为重要参考,但这两种有限数据评估模型的拟合效果尚需进行深入研究。  相似文献   

7.
欧盟和挪威共同确定了1998年北海主要经济鱼类的总可捕量,其中鲐鱼的最大可捕量为48.4万吨(1997年为40.7万吨),鲱鱼为25.4万吨(1997年为15.9万吨),鳕鱼为14万吨(1997年为11.5万吨)。都比上一年度有所增加,但削减了牙鳕和绿青鳕的总可捕量。根据协议,非欧盟成员国挪威可捕捞北海鲱鱼总可捕量的29%。双方还就2001年以前北海的渔获配额问题进行了研讨。  相似文献   

8.
厦门海域渔业资源评估   总被引:7,自引:0,他引:7  
以初级生产力和渔业统计资料为材 ,分别应用Tait沿岸海域生态系能流分析法、营养动态法和Cushing等 3种模式 ,估算厦门沿岸海域的渔业资源自然生产量。同时 ,分别应用Schaefer和Fox两种剩余产量模式估算最大持续产量和最大持续捕捞力量。前 3种模式估算该海域的资源生产量分别为 2 0 1 0 5t,1 8463t和 1 7489t,平均 1 8686t。后两种模式估算最大持续产量平均值分别为 9639t和 91 0 4t。估算的最大持续捕捞力量 :5种作业综合总功率为 1 5976kW ;以厦门机定置渔船单位功率渔捞效率为标准估算的总功率为 2 7351kW ;以厦门机刺网渔船单位功率渔捞效率为标准估算的总功率为 432 1 3kW。 1 997年实际渔获量和捕捞力量均超过了估算的最大持续产量和最大持续捕捞力量。文中还讨论了捕捞力量的调整问题。  相似文献   

9.
随着海洋渔业资源的不断衰退,为了保护渔业资源、推动海洋渔业的可持续发展,自20世纪70年代后期,我国出台了许多海洋捕捞相关政策。文章从投入控制制度、产出控制制度和技术控制制度3个角度出发,以捕捞许可制度、捕捞限额管理和伏季休渔制度等政策为重点,通过整理1980—2017年浙江省渔业经济的相关资料,从海洋捕捞渔船数量和功率、海洋捕捞产量、渔业劳动力数量变化3个方面,深入分析浙江省海洋捕捞现状,提出了完善现有的海洋捕捞政策、加强渔业执法管理力量、加强普法宣传、建立渔业资源调查与评估体系、帮助捕捞从业人员转产转业等对策建议,以期为我国海洋捕捞管理部门提供决策参考。  相似文献   

10.
石莉  李雪 《海洋信息》2006,(1):30-30
2005年9月1日,NOAA向美国国会发布了2004年美国渔业情报的年度报告。与先前的资源评估相比,这份报告体现了以下几点变化:一种渔业资源己被完全恢复:6种资源己停止过度捕捞;3种资源不再有过度捕捞的危险;5种资源正在被过度抽捞:还有3种资源已经被过度抽捞:还有3种资源已经被过度捕捞。  相似文献   

11.
Most fisheries in China do not have maximum sustainable yield(MSY) estimates due to limited and poor data.Therefore, finding a common method to estimate MSY or total allowable catch(TAC) for fishery management is necessary. MSYs of three important fisheries in the East China Sea were evaluated through a catch-based model.Estimates for intrinsic rate of increase(r) and five levels of process error were considered. Results showed hairtail Trichiurus japonicas(Temminck and Schlegel) and small yellow croaker Larimichthys polyactis(Bleeker) fisheries experienced overfishing from the mid-1990 s to the early 2000 s, and the suggested TACs were 55.8×10~4 t and9.06×10~4 t, respectively. Decades of overfishing in wintering and spawning grounds of large yellow croaker Larimichthys crocea(Richardson) caused the fishery's collapse in the 1980 s, and it has not recovered until today.The Catch–MSY model generated similar estimated MSYs with other methods and may be a useful choice for the assessment of regional stocks in China.  相似文献   

12.
It is important to find a reliable method to estimate maximum sustainable yield(MSY) or total allowable catch(TAC) for fishery management, especially when the data availability is limited which is a case in China. A recently developed method(CMSY) is a data-poor method, which requires only catch data, resilience and exploitation history at the first and final years of the catch data. CMSY was used in this study to estimate the biological reference points for Largehead hairtail(Trichiurus lepturus, Temminck and Schlegel) in the Yellow Sea and Bohai Sea, based on the fishery data from China Fishery Statistical Year Books during 1986 to 2012. Additionally,Bayesian state-space Schaefer surplus production model(BSM) and the classical surplus production models(Schaefer and Fox) performed by software CEDA and ASPIC, were also projected in this study to compare with the performance of CMSY. The estimated MSYs from all models are about 19.7×104–27.0×104 t, while CMSY and BSM yielded more reasonable population parameter estimates(the intrinsic population growth rate and the carrying capacity). The biological reference points of B/BMSY smaller than 1.0, while F/FMSY higher than 1.0 revealed an over-exploitation of the fishery, indicating that more conservative management strategies are required for Largehead hairtail fishery.  相似文献   

13.
大多数渔业种类由于数据缺乏,无法使用传统的渔业资源评估方法开展评估和管理。越来越多的研究采用CMSY等基于有限数据的评估方法,但CMSY方法在渔获量数据时间序列长度有限、存在误差等情况下的评估可靠性尚有待验证。本研究运用CMSY方法对黄海3种产量较高的经济鱼类开展资源评估,探索渔获量数据时间序列长度、不同渔业发展阶段,以及观测误差水平对评估结果的影响。结果表明,鲐、带鱼和银鲳在2000年后均出现产量高于最大可持续产量(MSY)的情况,资源处于过度利用状况(B/BMSY<1、 F/FMSY>1),近10年来开发强度降低,但生物量仍处于较低水平(B/BMSY<1)。评估模型的回溯性分析结果差异较小,表明评估结果稳定。从数据长度上看,使用遍历产量上升和下降过程的长时间序列数据,其评估结果更为稳定。在观测误差大于20%的情况下,模型对MSY和BMSY出现高估,但结果仍较为稳健。在CMSY方法的应用中应注意选取长时间序列的产量数据,在评估结果不确定性高的情况下应采取相对保守的渔业管理措施。  相似文献   

14.
《Journal of Sea Research》2007,57(2-3):114-125
Many flatfish species are caught in mixed demersal trawl fisheries and managed by Total Allowable Catch (TAC). Despite decades of fisheries management, several major stocks are severely depleted. Using the Common Fisheries Policy (CFP) as an example, the failure of mixed-fisheries management is analysed by focussing on: the management system; the role of science; the role of managers and politicians; the response of fisheries to management. Failure of the CFP management could be ascribed to: incorrect management advice owing to bias in stock assessments; the tendency of politicians to set the TAC well above the recommended level; and non-compliance of the fisheries with the management regulations. We conclude that TAC management, although apparently successful in some single-species fisheries, inevitably leads to unsustainable exploitation of stocks caught in mixed demersal fisheries as it promotes discarding of over-quota catch and misreporting of catches, thereby corrupting the basis of the scientific advice and increasing the risk of stock collapse. This failure in mixed demersal fisheries has resulted in the loss of credibility of both scientists and managers, and has undermined the support of fishermen for management regulations. An approach is developed to convert the TAC system into a system that controls the total allowable effort (TAE). The approach takes account of the differences in catch efficiency between fleets as well as seasonal changes in the distribution of the target species and can also be applied in the recovery plans for rebuilding specific components of the demersal fish community, such as plaice, cod and hake.  相似文献   

15.
In this study, utilization of catch-quota balancing mechanisms in the Icelandic demersal fishery, which allow for individual transferable quota to be transformed among species and transferred between years, is analyzed to determine whether annual catches closely adhere to total allowable catches on average. Icelandic landings data for 14 demersal fish species during 2001–2013 are compared to implemented total allowable catches as well as catch limits recommended by the Marine Research Institute (MRI) and a proxy for annual market values. Landings surpassed legal limits of total allowable catch in 27% of the cases (landings by species by fishing year), mostly due to species transformations, but TAC overages were not consistent for any species. Instead, catches of some species were consistently less than legal limits, with some indications that landings were related to profitability (i.e. landings were correlated with market value). However, landings surpassed MRI recommendations in 67% of the cases, and landings of four species (Atlantic wolffish, haddock, monkfish and redfish) consistently exceeded MRI recommendations. Therefore, discrepancies between scientific recommendations for catch limits and quotas selected through the political process may represent a higher risk to long-term sustainability than catch-quota balancing mechanisms.  相似文献   

16.
杨春蕙  刘琦  王迎宾 《海洋与湖沼》2022,53(5):1219-1224
当渔业资源出现衰退时,加强资源增殖放流以养护渔业资源、提高渔业产量对于渔业资源可持续利用具有重要意义;与此同时,增殖放流的实施会对基于资源开发与管理的评估的结果产生影响。基于2001~2015年间东海北部海域三疣梭子蟹(Portunus trituberculatus)渔业数据,采用增殖剩余产量模型,对东海北部海域三疣梭子蟹的最大可持续产量(MSY)及取得MSY时所需捕捞努力量(EMSY)和原存生物量(BMSY)进行了评估,并与传统Schaefer模型评估结果进行了比较。结果表明,当年增殖放流量约在3×106~95×106尾之间时,三疣梭子蟹年产量逐渐增加, MSY在14.2×104 t和14.6×104 t之间, EMSY基本在15×104吨位左右。增殖放流量增加,其对应的MSY也越高,能承受的EMSY也越高(从15×104~15.4×104吨位之间),相反BMSY则减小(从188.4×104 t降至186.6×104 t)。与传统的Schaefer模型评估结果相比,增殖剩余产量模型由于考虑了增殖放流生物量的因素,得到了MSY和EMSY有所增加,而BMSY有所下降的结论。研究结果有望为该研究海域三疣梭子蟹可持续地捕捞、放流与管理提供科学依据。  相似文献   

17.
The catch and effort data analysis(CEDA) and ASPIC(a stock assessment production model incorporating covariates) computer software packages were used to estimate the maximum sustainable yield(MSY) from the catch and effort data of Greater lizardfish Saurida tumbil fishery of Pakistan from 1986 to 2009. In CEDA three surplus production models of Fox, Schaefer and Pella-Tomlinson were used. Here initial proportion(IP) of 0.5 was used because the starting catch was roughly 50% of the maximum catch. With IP = 0.5, the estimated MSY from Fox model were 20.59 mt and 38.16 mt for normal and log-normal error assumptions, while the MSY from Schaefer and Pella-Tomlinson were 60.40, 60.40 and 60.40 mt, for normal, log-normal and gamma error assumptions respectively. The MSY values from Schaefer and Pella-Tomlinson models of three error assumptions were the same. The R2 values from those three models were above 0.6. When IP = 0.5, the MSY values estimated from ASPIC from Fox were 132 mt, and from logistic model were 69.4 mt, with R2 value above 0.8. Therefore we suggest the MSY of S. tumbil fishery from Pakistan to be 60–70 mt, which is higher than the latest catch, thus we would recommend that the fishing efforts for this fishery may be kept at the current level.  相似文献   

18.
采用底拖网方法调查研究了闽东近海春季(5月)和秋季(10月)游泳动物群落组成、生物多样性、资源密度及时空分布格局等问题。调查中出现游泳动物70种(鱼类47种,甲壳类18种,头足类5种),隶属于15目40科64属,以鲈形目种类最多(25种)。鱼类是主要游泳动物群落,春季鱼类个体数和重量分别占总渔获的66.4%和72.3%,甲壳类分别占比33.4%和26.9%,头足类分别占比0.2%和0.8%;秋季,上述三个类群在总渔获中的占比分别为56.6%和60.4%、42.0%和37.8%以及1.4%和1.8%。春季优势种包括红狼牙虎鱼(Odontamblyopus rubicundus)、三疣梭子蟹(Portunus trituberculatus)、孔虎鱼(Trypauchen vagina)等10种,秋季优势种为龙头鱼(Harpadon nehereus)、三疣梭子蟹、六指马鲅(Polynemus sextarius)等7种;两个季节共有优势种包括三疣梭子蟹、日本 (Charybdis japonica)、龙头鱼、棘头梅童鱼(Collichthys lucidus)和六丝钝尾虎鱼(Amblychaeturichthys hexanema)5种。秋季的生物多样性指数和均匀度指数高于春季。春季平均资源密度为1013.7kg/km~2和10.2×10~4ind/km~2,高于秋季的平均值(899.0kg/km~2和6.6×10~4ind/km~2)。总体而言,鱼类是闽东近海主要的游泳动物类群,其资源密度从近岸向外海呈降低趋势,春季的资源密度高值出现在闽东外海中部水域,秋季高值则出现在南部的闽江口等水域;其春季的优势种种类多于秋季,存在一定程度季节性更替现象。  相似文献   

19.
In recent years, the small pelagic fishery on the Pacific northwest coast of Mexico has significantly increased fishing pressure on thread herring Opisthonema spp. This fishery is regulated using a precautionary approach(acceptable biological catch(ABC) and minimum catch size). However, due to fishing dynamics, fish aggregation habits and increased fishing mortality, periodic biomass assessments are necessary to estimate ABC and assess the resource status. The Catch-MSY approach was used to analyze historical series of thread herring catches off the western Baja California Sur(BCS, 1981–2018) and the Gulf of California(GC, 1972–2018) to estimate exploitable biomass and target reference points in order to obtain catch quotas. According to the results, in GC,the maximum biomass reached in 1972(at the beginning of fishery) and minimum biomass reached in 2015; the estimated exploitable biomass for 2019 was 42.2×10~4 t; and the maximum sustainable yield(MSY) was 15.4×10~4 t.In the western BCS coast, the maximum biomass was reached in 1981(at the beginning of fishery) and minimum biomass was reached in 2017; the estimated exploitable biomass for 2019 was 3.2×10~4 t; and the MSY was 1.2×10~4 t.Both stocks showed a decrease in biomass over the past years and were currently near to point of full exploitation.The results suggest that the use of the Catch-MSY method is suitable to obtain annual biomass estimates, in order to establish an ABC, to know the current state of the resource, and to avoid overcoming the potential recovery of the stocks.  相似文献   

20.
At the Rio+20 meeting in June 2012, governments of the world committed to rebuilding fish stock sizes by 2015 at least to levels that can produce the maximum sustainable yield (MSY), even if that would require the temporary closure of fisheries. This study explores the outcomes of such action for European stocks. In 2012, only 8 of 48 stocks (17%) were abundant enough to produce MSY and with a business as usual scenario, this number would not increase by 2015. In contrast, if fishing was reduced to levels consistent with rebuilding and if some fisheries were temporarily closed, 50–70% of the examined stocks would be able to reach the Rio+20 target by the end of 2015. In this scenario, after three years with reduced catches, fish supply from European stocks would reach and exceed the levels of 2011 already in 2016. The implications for fish, fishers and fish consumers are discussed.  相似文献   

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