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1.
东海区海洋捕捞渔获物的营养级变化研究 总被引：4，自引：0，他引：4
根据东海区主要海洋渔业公司1950～1995年分品种渔获物产量的统计数据，分析了东海区渔获物营养级的变化过程，用平均营养级指数来评估东海区海洋渔业资源的开发利用状况。结果表明，经过几十年的捕捞开发，东海区渔获物的平均营养级已从1965年的3．5下降到1990年的2．8，自1974年后海区的产量主要依靠捕捞低营养级品种如马面鲍等而获得。东海区海洋捕捞渔获物营养级结构已经发生了变化，1974年后捕捞主要在低营养级品种内进行。另外还描述了东海区带鱼等品种的种群内部结构小型化、低龄化现象。 相似文献
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渔获物平均营养级（Mean trophic level of fishery landings,MTL）是目前评估人类捕捞活动影响的研究中使用最广泛的生物多样性指标之一。根据联合国粮农组织FAO提供的渔获生产统计数据,结合Fishbase提供的相关鱼种营养级数据,本文评估了1950-2010年太平洋、大西洋和印度洋各沿海国海洋渔业开发状态。研究发现,在全球三大洋75个主要捕捞国中,43个国家MTL呈显著下降趋势,发生了Pauly于1998年提出的“捕捞降低海洋食物网”现象;但是,仅16个国家MTL的下降是由于高营养级种类的衰退,而27个国家属于“捕捞沿着海洋食物网”的下降机制。此外,20个国家MTL呈恢复上升趋势,但是,该恢复上升趋势通常伴随着传统低营养级种类产量的大幅下降;在上述20个国家中,11个国家的低营养级鱼类产量呈显著下降趋势。需谨慎分析“捕捞降低海洋食物网”现象,掌握MTL的潜在变化机制。 相似文献
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西北太平洋沿海国海洋渔业资源可持续利用评价 总被引：2，自引：0，他引：2
根据联合国粮农组织FAO提供的1950—2010年西北太平洋各沿海国的渔获生产统计数据,结合Fishbase提供的相关鱼种营养级(TL)以及Sea Around Us Project Database提供的无脊椎动物营养级,探讨了61年来西北太平洋各沿海国渔获物平均营养级的变化情况,以此判定各沿海国海洋渔业资源可持续利用情况。结果表明:除朝鲜外,其他沿海国均出现"捕捞对象沿着海洋食物网向下移动"的现象;中国、日本、韩国、俄罗斯渔获物平均营养级降低的速度分别为0.26/10a、0.21/10a、0.24/10a、0.15/10a;由于各国采取的渔业管理措施不同,导致各国渔业资源出现不同的现状。渔获物平均营养级的变化情况能够反映捕捞活动下各海域海洋生态系统的变化情况,建议西北太平洋各沿海国建立起基于渔获物统计的海洋渔业资源可持续利用评价监测系统,以掌握各国海洋生态系统结构和功能是否健康,为建立基于生态系统的渔业管理提供基础。 相似文献
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东北大西洋是世界上重要的捕捞海域，气候变化对该海域捕捞产生了重要的影响。本文基于联合国粮农组织所提供的1982?2016年东北大西洋渔获产量数据，对该海域渔获物组成、多样性、平均营养级及主成分变化特征进行时间序列上的分析，并结合东北大西洋海域气候、环境因子，应用广义可加模型探究渔获物组成与气候变化之间的关系。结果显示:渔获物多样性的变化总体上呈下降趋势，2002?2010年间处于较低水平；平均营养级在2002年之前呈平缓下降的趋势，2002年之后开始波动上升，相关性分析表明这两个指标与海域环境因子的变化较为相关。对渔获物组成进行主成分分析显示，第一主成份变化的方差解释率达到35.3%，且与海域气候、环境因素有较高的相关性，第一主成分变化能够较好地表征气候影响下渔获物组成变化的情况。广义可加模型分析结果显示，渔获物组成变化的影响因素按解释率由高到低分别为:海表温度、海平面高度、盐度、海冰和北大西洋涛动指数。该研究有助于认识气候变化对海洋渔业资源及其结构组成的影响。 相似文献
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自1998年“捕捞降低海洋食物网”概念首次提出以来,渔获物平均营养级（Mean trophic level of fisheries landings,MTL）广泛用于评估捕捞活动对生态系统完整性的影响,并指导管理机构的政策制定。近年来研究表明,掌握MTL的潜在变化机制对于以MTL作为渔业可持续性指标至关重要。根据联合国粮农组织FAO提供的渔获统计数据,结合Fishbase提供的相关鱼种营养级,本文探讨了全球三大洋14个FAO渔区MTL的变化趋势,并进一步分析不同MTL变化趋势下高营养级鱼种和低营养级鱼种渔获量的变动情况。研究表明, MTL呈上升和回升状态均可能伴随着低营养级鱼种渔获量的下降。此外,通过观察营养级高于3.25鱼种的MTL以区分“捕捞降低海洋食物网”和“捕捞沿着海洋食物网”现象需考虑生态系统的群落结构和开发历程。利用渔获物平均营养级评价渔业可持续性必须综合考虑高营养级和低营养级鱼种,以及群落结构和开发历程的掩盖效应。 相似文献
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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
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中国近海渔业资源结构特点及演替的研究 总被引：1，自引：0，他引：1
渔业资源是一种不断变化和更新的生物资源,如能合理地开发和利用可望取得良好的经济、社会和生态效益及永续利用的目的。然而由于人类的过度的开发和利用,加之生态环境的日趋恶化,使得许多渔业资源遭到破坏而严重衰退。近十多年来我国渔业与世界渔业发展的总趋势相似,随着捕捞强度的盲目增加,使得许多传统渔业资源遭到不同程度的破坏,主要捕捞对象替代频繁,其结构发生了显著的变化,总趋势是:经济价值高的、个体大的、年龄结构复杂的和在生态系统中营养层次高的类群逐渐被经济价值低的、个体小的、年龄结构简单的和营养层次低的类群所替代;底层鱼类所占比例日益减少,中、上层鱼类及虾、蟹类比例逐年增加。
对渔业资源结构特点和演替规律的研究一直受到国内外学者的重视,许多国家为了保护其近海渔业资源和本国的渔业权益,纷纷宣布建立渔业保护区和专属经济区,并采取了一系列的保护措施,因此近年特别着重研究建立保护区后的渔业资源结构的变化( Gunnar,1989; Megrey and Wespestaa,1990; Pinhorn and Halliday,1990)。我国学者也有许多渔业资源方面的研究报告(中国海洋渔业资源编写组,1990;邓景耀等,1991；孙宗烨等,1987;宋海棠等,1990;罗秉征等,1992;1993)。本文探讨了近40年来我国近海渔业资源结构的特点及其演变规律及趋势,并对我国不同海区渔业资源的演变进行了比较,进而分析了我国海洋渔业资源变化的原因,旨在为更加合理地利用我国的海洋渔业资源,并为其持续发展提供科学依据。 相似文献
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东北大西洋是重要的海洋捕捞海域,该海域渔业栖息环境易受北极气候变化的影响。为此,本文基于1950-2012年东北大西洋FAO的渔获统计数据,对已开发的293种渔获物平均营养级(mTL)、营养级平衡指标(FIB)和渔获营养级分类(TrC)进行时间序列的统计,为进一步研究该海域渔业资源受北极气候变化的影响提供基础。研究认为,平均营养级(mTL)从1950年(mTL=3.71)下降至2012年(mTL=3.57),每年下降约0.02TL(r=-0.614;P<0.01),而近8年来营养级平衡指数持续下降。同时,研究表明,东北大西洋渔获物平均营养级和气候变化(海表温上升、北大西洋涛动和海冰缩减等)息息相关,其中渔获量出现高产值均在海表温异常年份:1956年、1976年和1997年。本文分析了东北大西洋渔获物营养级变动情况,为研究东北大西洋渔获组成变化与气候变化的关系提供研究基础,也为渔业资源的可持续开发提供了理论依据。 相似文献
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基于渔获量平均营养级的东印度洋渔业资源可持续利用评价 总被引：1，自引：0，他引：1
渔业资源可持续利用是渔业经济可持续发展的基础。本文根据联合国粮农组织提供的1950?2018年东印度洋渔业生产统计数据,结合Fishbase提供的相关鱼种的营养级,探讨了69年间东印度洋渔获量平均营养级(MTL)以及营养级平衡指数的长期变化趋势,以此来判定其渔业资源可持续利用状况。研究认为,1950?2018年东印度洋渔获量呈现稳步增长趋势,其中云鲥(Tenualosa ilisha)、鲱鱼(Clupea pallasi)、印度鲭(Rastrelliger kanagurta)为重要渔获种类,其累计年产量占总产量的比重均在10%以上。MTL变动大致可分3个阶段:1950?1974年渔获MTL总体处在高位,其值范围为3.39～3.71,平均值为3.60±0.07,期间年渔获量呈现稳定的增长趋势,平均年增长率为6.4%;1975?1999年渔获MTL呈现波动,其值范围为3.21～3.51,平均值为3.35±0.08,期间年渔获量呈现稳定的小幅度增长趋势,平均年增长率为4.8%;2000?2018年渔获MTL年间波动较小,其值为3.31～3.43,平均值为3.38±0.03,期间年渔获量呈现缓慢稳定的增长趋势,平均年增长率为1.6%。3个阶段的平均营养级平衡指数分别为0.59±0.22、0.94±0.14、1.25±0.04,其值呈现稳定的增长趋势且年间变化幅度越来越小,说明其群落结构越来越趋稳定。渔业资源的开发利用程度增加,而MTL下降程度较小,营养级平衡指数呈现上升趋势,说明渔获量的增加能够弥补MTL的下降;且仅统计营养级大于3.25的种类时,1950?1974年、1975?1999年、2000?2018年3个阶段的MTL平均值分别为4.16±0.04、4.18±0.04、4.19±0.03,呈现小幅稳定增长的趋势,表明高营养级种群渔业资源未受到破坏。研究认为,东印度洋海洋生态系统稳定,高营养级种群渔业资源处于未充分开发状态。 相似文献
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Ecosystem-based management is one of the most important approaches that may lead to reducing the impacts of fishing on ecosystems. In this context, we have assessed the impact of Iranian coastal fishing (using landing data of 49 exploited species) on the ecosystem of the North Sea of Oman (Sistan and Baluchestan Province), during the last decade (2002–2011), with emphasis on testing the occurrence of the “fishing down? phenomenon. The Mean Trophic Level (MTL) and Fishing-in-Balance (FiB) index are two indicators that we used for analysis. The data indicated that the increased total landings in this region might be related to the exploitation of marine fishery resources especially with regard to large pelagic fish. Over the past decade, moderate decreasing trends in MTL and an increasing trend in the FiB-index were observed. In this regard, an upward trend in the spatial expansion factor and also a downward trend in the piscivory index and in Primary Production Required (PPR) in the time period could all indicate a spatial expansion toward deep waters, the catching of the large pelagic piscivorous species, such as tuna, and a sign of fishing pressures on the ecosystem. The results suggest a range of fishery exploitation patterns throughout the food web but it seems that these patterns are not a consequence of ?fishing down?. We suggest that the monitoring research be continued in this region and these indicators should be used to make fisheries management decisions and to prevent the continuance of this trend in future. 相似文献
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我国海洋渔业地理信息系统发展现状 总被引：1，自引：0，他引：1
详细总结了我国海洋渔业地理信息系统的研究与应用现状,远洋渔业地理信息系统主要应用于金枪鱼、鱿钓业和秋刀鱼的资源分布、渔获量与渔场环境关系、渔情预报、渔场图绘制等方面,近海主要用于分析东海渔业资源分布和漂移特征、渔场环境分布、部分种类渔获量分布与环境关系及渔情预报等方面。除渔业资源与渔场领域外,渔业地理信息系统还被应用到渔船跟踪、捕捞违法行为判别、渔业信息发布和水产品查询,以及渔港建设等领域,国内学者在进行渔业地理信息系统技术应用的同时,还注重了其技术的研究及改进。 相似文献
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《Marine Policy》2013
This study presents the response of fisheries management to the extreme climatic events that affect marine capture fisheries and mariculture in Taiwan. Two regional approaches that can be applied universally to help capture fisheries and mariculture adapt to extreme weather events are also proposed. In the winter of 2008, an anomalously strong and continuous northeasterly wind caused by a La Niña event drove the cold China Coastal Current southward to penetrate the southern Taiwan Strait, and a portion of this current intruded eastward to the southern Penghu Archipelago. The cold current intrusion appreciably damaged marine aquaculture and the wild fish population, causing the death of more than 73 t of wild fish and 80% of cage aquaculture fish at the Penghu Islands. This extremely cold seawater event occurred between late January and the beginning of February 2008. To recover fishery resources around the waters of Penghu, fishery-related agencies adapted recovery measures over 3 years starting in April 2008 that included hatchery juvenile release, environmental monitoring, fishery subsidies, and ecological field investigations. This study suggests that responding to extreme climatic influences on fisheries and mariculture should include (1) establishing an early warning system by connecting fisheries agencies and marine research institutions to assist decision makers in performing time-adaptive measures, (2) temporarily suspending fishing activities after the occurrence of a natural disaster to help recover fishery resources and ecosystems, (3) altering the governance of farming fishing right so that fish farmers can temporarily transfer their aquaculture cages from high-risk areas to waters outside the influence of extreme weather events, and (4) continually filing surveys to understand the recovery status of marine ecosystems. 相似文献
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L. J. Paul 《新西兰海洋与淡水研究杂志》2013,47(4):569-587
The commercial fishery for snapper Chrysophrys auratus (Bloch and Schneider) in the Hauraki Gulf is one of New Zealand's principal marine fisheries. The snapper catch from this area declined by 22% in 1972, and by a further 4% in 1973, following 4 y of high catches by Danish seiners.Some of the decline can be attributed to economic factors within the industry, and adverse winter weather. However, the 1972 decline in Danish seine catches is an acceleration of an existing trend. It probably results from heavy exploitation of an accumulated stock, and from movement of a few strong year classes past the age at which they have contributed most to the catch. The slight recovery in the 1973 Danish seine catch resulted only from increased effort; catch per day at sea continued to fall. An improvement in catch and catch per day is unlikely for some years at least.Snapper catches by other methods (trawl, long line, and set net) also declined during 1972, but the available data on fishing effort do not allow a detailed analysis. The trawl catch in the gulf fell further in 1973 as fishing effort was diverted to other grounds, but the catch by lines and nets improved slightly. 相似文献
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Marcelino Ruiz-Domínguez Casimiro Qui?onez-Velázquez Dana Isela Arizmendi-Rodriguez Víctor Manuel Gómez-Mu?oz Manuel Otilio Nevárez-Martínez 《海洋学报(英文版)》2021,40(9):53-65
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
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China(herein referred as China’s mainland,and excluding Hong Kong,Macao and Taiwan)ranks as the world’s leading fishing nation,with approximately 11.1 million tons of domestic marine catch acquired in 2017.Marine fisheries resources in China are mainly exploited by its 11 coastal provinces and municipalities,and the development of fishing industry varies among them.However,few studies have examined the exploitation history of the 11 coastal provinces and municipalities.In this paper,we systematically quantified the exploitation history of marine fishery resources in China and then measured the vulnerability of the 11 coastal provinces and municipalities of China to a reduction in marine catches.Our analysis suggested that Chinese marine fisheries experienced rapid growth from the mid-1980 s to the end of the 20 th century,and this rapid increase in marine catches were mainly promoted by increased fishing effort.The total primary production required level amounted to approximately 80%of the average primary productivity in 2017,and Zhejiang,Fujian,Shandong,Hainan and Guangdong provinces were the main fishing provinces in China.By assessing three dimensions of vulnerability(exposure,sensitivity and adaptive capacity)to the impacts of a reduction in marine catches in the 11 coastal provinces and municipalities,we found that Hainan,Guangxi,Zhejiang and Fujian provinces had high or very high vulnerability,while the municipalities of Shanghai and Tianjin had low vulnerability.Identifying suitable adaptation policies and management plans based on the differences in vulnerability among coastal provinces is important in sustainable fisheries management. 相似文献