红碱淖海子大银鱼数量变动情况调查

红碱淖海子为高原型内陆湖泊，可养鱼面积5500hm^2，1995—1997年移植大银鱼卵5000万粒，1998年大银鱼产量357t。但由于水质恶化，饵料生物贫乏，1999年大银鱼产量仅18t，2000年仅17t，2001年产量为0。提出了恢复大银鱼产量的措施。     

红碱淖渔业资源及开发思路

一、红碱淖概况 红碱淖位于内蒙古鄂尔多斯高原与陕西省神木县的交界处，处于毛乌素沙漠的边缘。水体ｐＨ值为８．５左右，透明度１－５米，水质较好，是我国最大的沙漠型淡水湖泊，是发展渔业生产极好的场所。 二、开发思路 １．合理高效地开发利用红碱淖的水域资源，以提高红碱淖渔业综合效益。 一是下大力气控制 条的迅猛繁殖。 条已是水体的优势种群，成了水体—大害鱼，占水域水产品的４５％，产量高，但收效低，市场价１元／公斤，除去捕捞费０．４元／公斤，利润公为０．６元／公斤。笔者认为投放一定比例的美国加州鲈是非常有益的。…     

红碱淖渔业环境质量评价

根据2011年5月和8月的监测数据,采用单项污染指数法、综合污染指数法及营养状态指数法对红碱淖渔业环境水质进行评价,并结合以往监测数据和资料分析红碱淖水质污染趋势和盐碱度变化情况.结果表明:红碱淖渔业环境水质为重度污染,主要污染指标为pH、非离子氨、TP、TN和CODMn,在2005-2011年,污染呈上升趋势；营养状态指数表明湖泊处于富营养状态；自20世纪80年代起,湖泊盐碱度及硬度持续升高.     

大通湖鲢、鳙鱼放养效果的初步分析

大通湖是一个有十万亩水面的人工养殖湖泊。由于湖场变迁，饵料生物变化以及有无灌江纳苗，放湖家鱼种类数量规格变化等因素影响，鱼产量极不稳定。一九七七年以后基本没有灌江纳苗，主要依靠人工育种放湖，但由于投放量不大，规格又小，加上品种搭配不当，产量逐年下降，     

陕西红碱淖湖泊渔业环境质量状况评价

根据2011年实际监测数据，采用单项污染指数法、综合污染指数法及营养状态指数法对红碱淖湖泊渔业环境水质进行评价，并结合以往监测数据和资料分析了红碱淖湖泊水质污染趋势和盐碱度变化情况。结果表明：红碱淖湖泊渔业环境水质为重度污染，主要污染物为pH、非离子氨、TP、TN和CODMn；湖泊处于富营养状态，氮为富营养化的限制因数；在2005年-2011年，污染呈上升趋势；自80年代起，湖泊盐碱度及硬度持续升高，已对淡水鱼类生存构成严重威胁。     

太湖鲌鱼数量变化规律及生态效应分析

通过2003~2005年的食性分析和渔获物组成调查,研究了太湖翘嘴红鲌、蒙古红鲌数量变化的规律及在鱼类群落演替过程的作用。食性分析表明:太湖翘嘴红鲌、蒙古红鲌主要摄食鲚鱼,其次是小型鱼类和虾。其中鲚鱼在翘嘴红鲌、蒙古红鲌消化道的出现率分别为95.24%、59.26%;在翘嘴红鲌食物中的重量组成比例为59.2%±11.4%。渔获量统计表明:1952~1958年鲌鱼平均年产量为406.4±102.5 t、占渔获总量的6.28%±0.85%;1987年达到历史最高产量1 090.8 t、占渔获总量7.65%;1993年后鲌鱼资源在快速减少,由1993年的922.3 t、占6.55%下降到近年的100~160 t、仅占渔获总量的0.4%~0.8%。2004年调查表明,在74 667kg渔获物中,翘嘴红鲌、蒙古红鲌仅占0.0038%。分析历年渔获量变化趋势发现,随着鲌鱼数量的不断减少,鲚鱼和小型其它鱼类均呈相反的快速增加趋势,而银鱼则有大体一致的持续下降趋势。简单相关和偏相关分析发现,鲌鱼-鲚鱼、鲌鱼-小型鱼类渔获量的负相关关系达到显著水平;鲌鱼-银鱼渔获量的正相关关系达到显著水平。研究认为:太湖翘嘴红鲌、蒙古红鲌对鲚鱼和小型鱼类有很强的抑制作用,对银鱼可能有间接促进作用;人为过度捕捞使翘嘴红鲌、蒙古红鲌数量不断减少,从而导致鱼类群落向鲚鱼为绝对优势种、小型鱼类不断增加的方向变化。鲚鱼和小型鱼类主要摄食浮游动物,其快速增加抑制了浮游动物、有利于浮游植物生长,这是太湖蓝藻频繁暴发的生物学因素之一。     

海洋岛渔场的综合治理意见

海洋岛渔场是我省近海主要渔场之一，总面积达3052了平方公里。该渔场是多种鱼、虾的良好产卵、肥育、越冬场所，鱼类资源丰富，产量占全省总产量的近四分之一。多年来，由于捕捞强度不断增长，鱼类资源受到破坏，虽然总产量波动不大，但是传统性鱼类产量有所下降，小型鱼类如鲤鱼等数量增多。为了合理利用近海渔业资源，本文根据该渔场的鱼类生产的变化情况，提出该渔场综合治理的意见。     

西江肇庆江段渔业资源现状及其变化

2006～2007年的4～6月对西江肇庆江段渔业资源进行调查.西江渔民主要以三层流刺网、抛网为主要作业网具.调查共采集鱼类75种,隶属23科、65属.与历史资料对照,目前西江肇庆江段鱼类的种类组成与结构已发生较大变化.捕捞种类主要为广东鲂、赤眼鳟、鲮、鯿、海南红鲌、花(鱼祭)、黄尾鲴、鲤、鲢、草鱼等.中华鲟、鲥鱼、三线舌鳎等已经在渔获物中消失、鳗鲡、花鳗鲡、卷口鱼、大眼红鲌等重要经济鱼类甚为少见.四大家鱼的资源量日趋衰竭,其中鳙的数量相对出现较多,而青鱼和草鱼产量极少.不同种类的渔获物在不同江段的分布具有明显差异性,广东鲂在产卵场江段有明显的集群现象.广东鲂、鲮、鳊和花(鱼祭)等捕获规格有所下降,可能是捕捞压力过大导致,而赤眼鳟、黄尾鲴的捕获规格有所增加,资源种群状况比历史上的好.     

浅谈张家口地区养鱼水域生态建设及其发展前景

我区淡水总面积由六十年代初期拥有60万亩,锐减到1986年24万亩,养鱼面积由24.7万亩下降为15万亩,渔业总产量比六十年代初期1104顿的最高产仅仅只增加20％,养鱼水域生态尤其坝上地区湖淖遭到严重破坏,主要产鱼淖渔业绝收。怎样来实现中共中央和国务院提出的力争到本世纪末全国水产品产量翻两番?本文     

评估水库鱼类与饵料生物相关的生物量模式

美国国家水库研究课题提出了一个数学模式，用以帮助渔业管理者来评估水库中鱼类的食物链关系，以及评定水库运转的变化结果，还可用来评估渔业管理实施状况或鱼产量和饵料生物之间的变化。输入数据为在鱼类生长季节中采样测得的鱼的现存量(单位面积的重量，按不同品种和不同规格计算)。此模式可用来测定饵料植物腐植质、底栖生物、浮游动物、鱼类和陆生无脊椎动物等维持鱼类生存的生物量。还可提供鱼产量的估计值和一年内鱼类所食饵料的数量。     

Hydropower and instream flow requirements for fish in Sweden

SwedPower AB, Stockholm, Sweden Standardized methods for determining instream flow needs in connection with hydropower development have still not been established in Sweden. However, claims related to conflicting uses of running waters have long engaged the Water Right Courts. Historically, the floating of timber has constituted a strong reason for regulating rivers. Later, the creation of large reservoirs and the subsequent alteration of the natural river flow have mainly been related to the generation of hydroelectricity. In recent decades, the expectations of stakeholders have also been directed at recreational fisheries and the maintenance of biodiversity. Dry channels below diversion points are no longer considered acceptable. Swedish legislation allows for a regular review and reissue of permits to regulate rivers and operate hydroelectric power plants. However, it is only possible to enforce changes which are economically reasonable. The maximum loss of electricity which must be endured by a producer without reciprocal demands of compensation amounts to 5%. Presently, fishing may be regarded as the second most important interest in terms of the use of river resources. Accumulated knowledge of fish ecology makes it possible to use models for the management of fish populations. However, decisions regarding minimum releases of water are usually still based on the natural hydrograph rather than on documented relationships between fish yield and the characteristics of the watercourse. Over the past 7 years, Vattenfall, the largest producer of hydroelectricity in Sweden, has carried out research and development to test, improve and introduce instream flow methods for the management of regulated rivers. Experiences regarding biotope adjustments as an alternative to increased releases of water are presented, and the economic and biodiversity aspects are discussed.     

湟水流域水生态保护与修复研究

研究湟水流域水生态现状和保护与修复措施,加强湟水流域水生态保护,维持黄河尤其是黄河上游流域及青藏高原和黄土高原-川滇生态屏障生态安全。湟水干流、大通河梯级开发集中,河流纵向连通性遭到严重破坏,且大部分水电站是引水式小水电站,枯水期水电站下游河道脱流现象严重,河流水流连续性及横向连通性遭到破坏,河流生态功能严重下降。根据国家及黄河流域对湟水流域生态保护定位及要求,在湟水流域水生态状况评价及问题识别的基础上,明确各区域(河段)水生态保护目标,提出了湟水上中下游水生态保护与修复总体布局、重要断面生态需水指标及保障措施和重要湿地、重要鱼类栖息地等保护与修复措施体系。     

Rapid change in Yangtze fisheries and its implications for global freshwater ecosystem management

Freshwater capture fisheries are globally essential for food security and aquatic biodiversity conservation. The Yangtze River Basin is the third longest and one of the most human‐influenced drainage basins worldwide. Since the founding of P. R. China in 1949, this large river system has suffered increasing human perturbation and its sustainable development is now severely challenged. Meta‐analysis showed that Yangtze River fisheries have experienced an extraordinary process of utilization–over‐exploitation–protection during the past 70 years, to an extent that other globally important rivers may never have encountered. Its fisheries appear to have collapsed over the past four decades, with yield decreasing to only 25% of an historical peak of 400,000 metric tonnes in the late 1950s. Endemic, migratory and rare fishes have been highly threatened with obvious changes in fish community structure and aquatic biodiversity. Anthropogenic activities, including impoundment of water in dams, discharge of pollutants and riverine modification for vessel navigation, have caused large decreases in fisheries yields. Projections from surplus production modelling showed potential for improvement under fishing ban scenarios, but without any prospect for full recovery to historical stock status. This study revealed that the change in fisheries resources was dominated by the social–ecological watershed system, and an integrated approach to river basin management is warranted. Better management of freshwater ecosystems to integrate food security with biodiversity conservation is urgently needed throughout the world, and the changes evident in the Yangtze River fish populations can serve as an informative global reference.     

Temporal changes in fishing motivation among fishing club anglers in the United States

Responses from freshwater anglers (n = 4287) to a nationwide survey of the US fishing club members were used to assess differences in the importance of 16 fishing motivation items between 1987 and 1997, dates that preceded and followed a period of substantial decline in recreational fishing participation in the US. Comparison of respondents’ motivations for fishing in 1997 and 10 years earlier indicated consistency in the paramount importance of being outdoors, relaxation and the experience of the catch. However, the importance of family recreation and being with friends in 1987 were replaced by escape items in 1997. Anglers with fewer dependents and living in areas with higher population density were more likely to decrease the importance of family recreation. Younger anglers were more likely to decrease the importance of being with friends. Anglers who had higher household income, fished more and had higher fishing expenditures were more likely to decrease the importance of obtaining fish to eat. The results of this study suggest that managers should be less concerned about angler opposition to liberal regulations that allow anglers to harvest fish, and that heightened efforts to recruit and retain recreational anglers, which presently focus on family recreation, should be broadened to include outdoor experience, relaxation and escape aspects of fishing.     

Ecosystem‐based management of Amazon fisheries and wetlands

Infrastructure development and overfishing in the Amazon make it imperative to define adequate scales for the ecosystem‐based management of commercial fisheries and the wetlands on which they depend. We mapped fisheries and fish ecology data from Brazil, Peru, Bolivia and Colombia to an explicit GIS framework of river basins and mainstems. Migratory species account for more than 80% of the known maximum catches of commercial fisheries across the Amazon. Of these migratory species, we nominated six long‐distance migratory fish taxa as flagship species to define the two main commercial fishery regions. The migrations of at least one goliath catfish species define a large‐scale longitudinal link joining the Andes, Amazon Lowlands and Amazon River estuary. Migratory Characiforms demonstrate interbasin wetland connectivity between nutrient‐rich and nutrient‐poor rivers over at least 2 million km², or about one‐third of the Amazon Basin. We show that flooded forest area is the most important wetland variable explaining regional variations in migratory characiforme biomass as indicated by maximum annual fishery catches. The sustainable management of Amazon fisheries will require transnational cooperation and a paradigm shift from local community management alone to a more integrated approach that considers both rural and urban consumers and challenges, and the realistic life histories of migratory species.     

长荡湖水生植被动态及其渔业效应的研究

本文根据1983年—1984年调查研究结果分析整理而成。文中论述了长荡湖现有水生植被的种类组成,群落结构,生态分布,沉水植物的生物量及其利用。经过分析比较,发现近30年来,长荡湖水生植被经历了旺盛—衰竭—恢复—旺盛的演替过程,揭示了引起植被变化的各种因素。随着水生植被的动态变化,长荡湖的鱼类种群结构,渔获对象及捕捞工具都相应发生了变化。植被的盛衰同浮游植物和浮游动物、底栖生物的消长丰歉有着密切的关系.本文最后指出了长荡湖水植被的演替趋势和潜在危机,强调了合理利用和定向改造水生植被的重要性,并对今后如何发展我国湖泊渔业提出了建议。     

The risk of individual fish being captured multiple times in a catch and release fishery

The proportion of angled Atlantic salmon Salmo salar L. being caught and released has increased. If individuals are repeatedly captured, this may have fish welfare consequences. Of 995 Atlantic salmon tagged during catch and release in eight Norwegian rivers, 10% were captured twice, while 3% were captured three times within the same fishing season. The probability that released salmon were captured again decreased with decreasing time left of the fishing season, decreased for larger‐sized fish and varied among rivers/years. Increased exploitation rates within the river, indicating an increased fishing pressure, strongly increased the probability that fish would be recaptured. However, the proportion of salmon caught a second time was much lower than the total exploitation rates in the same rivers (which was on average 46%). For fish tagged in the sea, the likelihood of being angled decreased with time since entering the river, which may explain why the recapture rates of caught and released fish were lower than the total exploitation rates.     

黄河三角洲水质污染对淡水鱼类多样性的影响

1993-1997年对黄河三角洲8条河流、3个水库和1个湖泊水质连续5年进行了监测，1996-1997年对淡水鱼类多样性开展了同步系统调查，水质评价结果：6条河流为重污染，2条河流为严重污染，2个水库轻污染，麻大湖严重污染，淡水鱼类共鉴定出102种和亚种，隶属于9目17科65属，占山东省炎水鱼类总种数的89%。水质污染已志致鱼类多样性减低，少数河流鱼类绝迹。     

河湖水生态系统服务价值核算研究及应用展望

科学有效地界定河湖水生态系统服务价值评估体系与评估指标，促进河湖水生态的可持续发展、合理制定水资源价格、为河湖水生态系统服务价值评估提供参考，同时也为河湖水资源纳入国民经济核算体系提供借鉴，为绿色经济核算提供有力的依据。从河湖水生态系统服务功能、评估体系和评估方法等方面总结了国内外研究进展，分析了现有河湖水生态系统服务体系和评估方法的优缺点。优化后的河湖水生态系统服务评估体系包括供给服务、调节服务、文化服务和支持服务4大类以及水资源供给、水质净化、科研教育和固碳能力等19项指标，优化了水资源供给、提供水产品、水质净化、防洪减灾、休闲娱乐、生物多样性保护等6个指标的评估方法。下一步要制订GEP核算技术标准，建设市场化、多元化的生态产品交易体系，将水资源开发、利用及保护情况、水资源管理生态环境效益等指标纳入审计范围，建立以水生态系统为整体、以维护河湖生态系统健康为总目标、以定量评判和可操作性为抓手的新的河湖长制考核体系。