浙江省中型水库的渔业类型和合理放养问题的初步探讨

在湖泊，水库的渔业利用中，就其渔业上的分类一般是基于鱼类组成和鱼产量两种。从目前以放养鲢、鳙鱼为主的水库渔业的渔获物种类组成分析结果，鲢、鳙鱼在数量上和产量上均占主要地位。所以，从鱼类组成上划分水库渔业类型已很不确切和没有多大实际意义了，而按渔业生产力(即鱼产量)的高低来划分水库的渔业类型则更近乎实际。因此，本文所探讨的水库渔业类型，     

陕西典型生态养殖大水面渔业资源调查

为加快推进陕西大水面生态渔业发展，对陕西典型生态养殖大水面冯家山水库的渔业资源现状进行了调查和分析。结果显示，水库共鉴定鱼类4目6科15种，以鲤科鱼类为主。渔获物在数量方面，以麦穗鱼为主，占比63.49%；在体质量方面，以鳙、鲫和鲢为主，占比分别为32.40%,26.97%和19.85%。鱼类Shannon-wiener多样性指数平均值为1.30,Margalef丰富度指数平均值为1.70,Pielou均匀度指数平均值为0.48。提出，需增加放养鱼类品种来丰富水体食物链，调整鲢、鳙放养密度和放养规格，逐步降低大银鱼放养量，实现渔业生态养殖可持续发展。     

傀儡湖鱼类群落结构及其食物组成研究

为了分析傀儡湖鱼类对水环境的影响,于2010年1-12月研究了傀儡湖的渔获量、组成比例和主要鱼类食物组成。结果表明,傀儡湖渔获物中,发现有9科、26种鱼类,其中鲤科鱼类最多,有18种,占鱼类种数的69.23%;鱼类组成中,鲢和鳙为优势种,分别占总渔获量的（20.82±8.06）%和（41.58±19.24）%;主要鱼类...     

富水水库渔业增殖措施及其效果

渔业增殖工作包括重点保护增殖底栖杂食性鱼类,合理控制利用凶猛鱼类,移植引进鱼类新品种以及投放大规格鲢、鳙鱼种等综合措施.总渔获量由1985年的250吨,增至1990年的881吨.底栖杂食性鱼类由占渔获物总量的29.1％上升为46.1％,肉食性凶猛鱼类由62.5％降至34.8％。移植入库的太湖新银鱼已能在库中自行繁衍。     

衡水湖鱼类资源调查

2004年3月至2006年3月,对衡水湖的主要经济鱼类资源进行了调查。共鉴定出鱼类34种,隶属于7目13科32属。鲤、草鱼、鲫、尼罗罗非鱼、鲶、鳙、鳜、黄鳝、乌鳢、黄颡鱼、鲢、泥鳅、红鳍鲌等12种鱼是衡水湖的主要优势种群。鲤科鱼类最多,计17种,占鱼类总数的50%;鲤占渔获物的重量比例和尾数比例最大(44.68%和10.47%)。衡水湖的鱼产力在下降,过度捕捞是造成渔获物个体小型化和低龄化的主要原因。提出了衡水湖鱼类资源增殖和生态保护措施。     

汤河水库近期鱼类结构及主要经济鱼类生长特性

2007和2008年5～10月间对辽宁省汤河水库鱼类进行了现场采集和分析,共收集到鱼类18种,分别隶属于5科18属。其中鲤科14种,占77.8%;鲿科、鲇科、鮨科、鳢科各1种,占22.2%。5月、8月、10月鲢、鳙比例占渔获物平均数的71.6%,年龄为1至5龄,其中2～4龄鱼比例占82%;鲢和鳙的体长生长和体重生长分别为:Lt=L∞[1-e-(kt-t0)]和Wt=W∞[1-e-(kt-t0)]3。     

鄱阳湖渔业资源现状与养护对策研究

鄱阳湖是我国第一大淡水湖,渔业资源十分丰富,有鱼类136种,占长江鱼类种数的36.76%、江西鱼类种数的66.34%。近年来,鄱阳湖渔业资源衰退明显,主要表现为捕捞产量逐年下降,渔获物种类减少,小型定居鱼类和低龄鱼比例上升。笔者对鄱阳湖2000-2006年渔业资源变化及原因进行了分析,并从加强资源监测、养护技术研究,修复渔业生态环境等方面提出了保护的措施建议。     

长江葛洲坝水利枢纽兴建后对中、上游主要经济鱼类影响的综合评价

作者详细分析研究了葛洲坝枢纽工程对长江中上游的环境状况、水文条件、鱼类区系、渔获物组成以及青、草、鲢、鳙等多种主要经济鱼类的影响程度,并进行了综合评价,为保护和发展江河渔业提供了科学依据。     

二龙湖水库的鱼类群落结构

2017年2月和7月对二龙湖水库开展了鱼类群落结构调查,共采集到鱼类22种,隶属于4目8科22属,以杂食性鱼类为主,其中鲤科鱼类占59.09%,主要的经济鱼类为鲢、鲫和鲤。对调查获得的22种鱼类产卵类型进行分析结果显示,产黏性卵鱼类和漂浮性卵鱼类分别占总种数的68.18%和27.27%。夏季渔获物的种类、数量和多样性指数都高于冬季。库区鱼类具有群落结构简单化、鱼类资源小型化的特点,资源前景不容乐观,需加强保护措施。     

长江鲢、鳙鱼比珠江鲢、鳙鱼生长快

鲢、鳙鱼是我国池塘养殖和天然水域增殖的主要对象,其产量占池塘养鱼总产量的50%左右,占湖泊、水库养鱼总产量的70—90%。鲢、鳙鱼又是我国特有的鱼类,资源非常丰富。在我国悠久的鱼类养殖史上,鲢、鳙鱼素有长     

做好渔业标准化工作全面提升我省渔业经济质量

<正>渔业标准化是规范渔业生产、保障消费者安 全,促进渔业经济发展的有效措施,是现代化渔业 的重要标志。我国经济体制改革以来,渔业标准 化工作取得了较大的进展。 全国渔业标准化工作概况 一是制标数量不断增加,标准内容不断拓展。 截止至2004年4月底,我国现行水产国家、行业     

国际渔业动态

2020年全球水产品贸易前景比2019年更具不确定性预计2020年全球水产品产量与2019年持平,总量约1.778×108 t。快速发展的水产养殖业继续稳步发展,2019年养殖产量估计增长了3.9%。2019年,尽管由于亚洲经济增长缓慢,人工养殖虾类的前景不太明朗,但三文鱼类、罗非鱼类和巴沙鱼类等大多数具有重要商业价值的人工养殖鱼种产量稳定增长。据估计,2019年野生渔获量下降了3.4%,这主要是由于秘鲁凤尾鱼类渔获量的急剧下降。在其他地方,头足类的供应一直很紧张,鳕鱼类的捕获量也很有限。然而,金枪鱼类的产量一直在增加,供应压力使金枪鱼的价格持续降低。野生鱼类现在占我们所食用鱼类的45%,且这一比例还在继续下降。     

Reef fisheries in Porto Seguro, eastern Brazilian coast

Fish landings in Porto Seguro, in the eastern Brazilian coast, were monitored from September 1997 to August 1999 to describe the predominant species caught, the catch per unit effort (CPUE) and patterns of yields according to depth and season. A total of 223.5 t from 352 fishing trips made by a fleet of 53 boats was monitored. The fishery is conducted at depths from 20 to 150 m. The number of commercially valuable species caught was high (n=53). Snappers (Ocyurus chrysurus, Lutjanus analis and L. jocu) made up 38% of total catch. Pelagic species such as Coryphaena hippurus, Seriola dumerili, Thunnus albacares and T. atlanticus accounted for 43% while groupers, mainly Mycteroperca bonaci, represented 10%. Relative abundance of these target species was strongly dependent (P<0.001) upon depth and season. Higher yields of O. chrysurus (>20 kg/fisher per day) were observed between 20 and 40 m, from April to June. During spring–summer, yields of oceanic pelagic species increased rapidly, and catches of C. hippurus (40 kg/fisher per day) rose from November to January.     

Krill fisheries: Development,management and ecosystem implications

There are currently at least six commercial fisheries harvesting six different species of euphausiid, or krill: Antarctic krill (Euphausia superba), fished in the Antarctic; North Pacific krill (Euphausia pacifica), fished off Japan and off western Canada; Euphausia nana, fished off the coast of Japan; Thysanoessa inermis, fished off the coast of Japan and off eastern Canada; and Thysanoessa raschii and Meganyctiphanes norvegica which have been experimentally harvested off eastern Canada. The current world catch of all species of krill is over 150 000 tonnes per annum but few fisheries are being exploited to their maximum theoretical potential. The size of the world krill harvest is currently limited by lack of demand, although some fisheries are being deliberately managed at low levels because of ecological concerns. We have outlined the history of these krill fisheries to determine where there are common trends and issues which will affect their future development. Krill products are currently mostly used for the aquaculture and sport fishing market but considerable effort has also been put into developing products for human consumption, particularly from Antarctic krill. The future development of krill fisheries is examined in the light of information on trends in krill products which include pharmaceutical and industrial uses in addition to nutritional products. Because of the central ecological role of krill in many marine ecosystems, the subject of krill harvesting is a sensitive issue and krill fisheries require careful management. This requirement has spawned an innovative international management regime in the Antarctic — the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) — which has developed procedures for managing the harvest of Antarctic krill that may be applicable to other fisheries. The common problems of managing krill fisheries are outlined particularly those relating to the role of krill in many coastal ecosystems, and as prey for many other species which are commercially fished.     

国际渔业动态

SFP公布全球水产品可持续性数据工具 可持续渔业伙伴组织(Sustainable Fisheries Partnership,SFP)与其他4个非政府组织公布了在全球范围内可以衡量水产品可持续性数据的工具供公众使用。这款“水产品可持续性数据工具”是为了给用户提供关于“全球水产品环境的可持续性和社会责任性”的图片或数据,其中也同时包含了8个重点水产部门的详细情况。     

Size structure,not metabolic scaling rules,determines fisheries reference points

Impact assessments of fishing on a stock require parameterization of vital rates: growth, mortality and recruitment. For ‘data‐poor’ stocks, vital rates may be estimated from empirical size‐based relationships or from life‐history invariants. However, a theoretical framework to synthesize these empirical relations is lacking. Here, we combine life‐history invariants, metabolic scaling and size‐spectrum theory to develop a general size‐ and trait‐based theory for demography and recruitment of exploited fish stocks. Important concepts are physiological or metabolic scaled mortalities and flux of individuals or their biomass to size. The theory is based on classic metabolic relations at the individual level and uses asymptotic size W_∞ as a trait. The theory predicts fundamental similarities and differences between small and large species in vital rates and response to fishing. The central result is that larger species have a higher egg production per recruit than small species. This means that density dependence is stronger for large than for small species and has the consequence that fisheries reference points that incorporate recruitment do not obey metabolic scaling rules. This result implies that even though small species have a higher productivity than large species their resilience towards fishing is lower than expected from metabolic scaling rules. Further, we show that the fishing mortality leading to maximum yield per recruit is an ill‐suited reference point. The theory can be used to generalize the impact of fishing across species and for making demographic and evolutionary impact assessments of fishing, particularly in data‐poor situations.     

Social, economic and cultural perspectives of European inland fisheries: review of the EIFAC symposium on fisheries and society

The contributions presented at the EIFAC Symposium on Fisheries and Society in 2000 are reviewed. There have been considerable advances in many sectors of inland fisheries over the past decade. Nowadays the value of inland fisheries to society is generally better understood and increasingly recognized. However, it was recognized that the allocation of fishery resources and their management could still be made more effective through more extensive application of the recent approaches and techniques discussed during the Symposium and reviewed in the paper.     

Risk management for fisheries

Risk management methods provide means to address increasing complexity for successful fisheries management by systematically identifying and coping with risk. The objective of this study is to summarize risk management practices in use in fisheries and to present strategies that are not currently used but may be applicable. Available tools originate from a variety of disciplines and are as diverse as the risks they address, including algorithms to aid in making decisions with multiple stakeholders, reserves to buffer against economic or biological surprises, and insurance instruments to help fishermen cope with economic variability. Techniques are organized in a two‐stage framework. In the first stage, risks are identified and analysed. Strategies presented in this category focus on decision analysis, including multicriteria decision‐making tools, and the related concept of risk assessment. Then in the treatment stage, identified risks can be transferred, avoided, or retained using tools such as the Precautionary Approach, portfolio management, financial contracts to manage price risk and horizontal integration. Published fishery applications are reviewed, and some empirical examples of risks and risk management using US fisheries data are presented.