太湖湖鲚渔获量及年龄结构变化与环境间的相互关系

在太湖,随着鱼类总渔获量的不断增加和鱼类种类的不断减少,湖鲚(Coilia ectenestaihuensis Yen et Lin),一种小型浮游动物食性鱼类已成为绝对优势种.根据1952-2004年的统计数据和2003-2005年对湖鲚年龄结构和食物组成的调查,研究了湖鲚快速增加的原因以及与环境间的相互关系.结果如下:(1)在1952到2004年期间,湖鲚渔获量从1952年的640.5 t、占总渔获量的15.8%上升到2004年的21 221 t、占63.8%.尤其是1994年后湖鲚渔获量以每年1280.5 t的速度增加;(2)湖鲚种群年龄结构低龄个体呈现不断增加趋势.1979和1980年0 个体仅占33%和34%,而2003和2004年0 个体分别上升到99.04%和99.08%;(3)0 湖鲚主要摄食浮游动物.按照个数组成比例计算,枝角类平均占89.77%±13.69%、桡足类占7.84%±11.53%、轮虫仅占2.39%±4.95%.分析认为:江湖阻隔、过度捕捞、富营养化不断加重等人类活动以及太湖特有的鱼类生态学特点是导致湖鲚渔获量不断增加、年龄结构发生变化的根本原因.随着湖鲚数量的快速增加,在湖鲚生长期间太湖浮游动物现存量呈现相应下降趋势,这可能使太湖浮游植物更易暴发.     

禁捕前鄱阳湖鱼类群落多样性及环境影响因子研究

为掌握鄱阳湖鱼类群落特征，课题组于2020年春季(5月)、夏季(8月)、秋季(11月)和2021年冬季(1月)4个季度，在鄱阳湖10个区域5种生境开展鱼类资源调查研究，同步采集水环境样品。研究共采集鉴定鱼类67种，隶属于8目14科47属，其中鲤科鱼类物种数最多(41种)，占比为61.19%。基于不同分组，鱼类生态类型分别以定居性鱼类(67.16%)、杂食性鱼类(44.78%)、中下层鱼类(35.82%)占据优势。该群落以小型鱼类为优势类群，数量占比为68.70%；鱼类优势种共有6种，第一优势种为似鳊。鱼类群落结构在季节上存在显著性差异，春季鱼类物种多样性指数高于冬季。非度量多维尺度分析(NMDS)显示，空间上鱼类可划分为2个类群，分别为湖口区类群和草型湖区-湖汊区-湖心区-沿岸带类群。冗余分析(RDA)显示，总磷、叶绿素a和透明度是影响鱼类物种时空分布的关键环境因子。丰度/生物量比较曲线(ABC曲线)分析表明，鱼类群落受到严重干扰(W=-0.091)。本研究成果可为鄱阳湖禁渔效果评估和鱼类多样性保护提供科学依据。     

南太湖入湖口蓝藻生物量与氮营养因子的年变化特征以及相关性研究

为了解南太湖水域近年来水质状况,以及蓝藻生物量与氨氮和总氮之间的变化规律,实验采用统计学方法,对南太湖水域3个入湖口(小梅港、新塘港、大钱港)水质中蓝藻生物量、氨氮和总氮的年变化特征进行了调查;使用SPSS10.0中的Bivariate(pcarson)软件对蓝藻生物量与氨氮和总氮的相关性进行了分析。结果表明:(1)南太湖入湖口蓝藻生物量一般有两个高位期,一个是在每年5—6月,另一个在每年的9—10月;(2)南太湖入湖口的总氮浓度处于富营养水平,并有向重富营养化发展的迹象;(3)蓝藻生物量与氨氮浓度的相关性系数r介于0.102～0.290,呈现不相关;(4)2008—2009年蓝藻生物量与总氮浓度的相关系数r介于0.010～0.210,呈现不相关;2010年蓝藻生物量与总氮浓度的相关系数r介于0.430～0.474,呈现低度负相关。结果说明南太湖入湖口的氮营养盐已经不容忽视,湖泊中氨氮和总氮浓度升高,将为蓝藻的繁殖生长提供条件,蓝藻一旦暴发,氨氮和总氮浓度反而迅速降低,在南太湖水域蓝藻生物量与氨氮和总氮浓度之间存在一定的此消彼长规律。     

Effects of eutrophication on fish and fisheries in Finnish lakes: a survey based on random sampling

Abstract The effects of eutrophication on fish and fisheries in Finnish lakes were determined by an extensive lake survey conducted in 1995 and 1996. The study lakes (873) were chosen by stratified random sampling from all Finnish lakes with a surface area ≥ 0.04km² (29,515 lakes in all). The chemical parameters of the lake water were determined for water samples taken in autumn 1995. Information on the fish stocks of the study lakes was collected by means of a postal questionnaire sent to local fishing authorities and lake owners. The results show that the fish community structure is cyprinid dominated, reflecting eutrophication in 2100 lakes (7% of all the target lakes). Strong fouling of the fishing gear, as well as a great abundance of unwanted species in the catch of passive gears, were considered to be a continuous problem in more than 10% of the lakes. Roach, Rutilus rutilus (L.), and bream, Abramis brama (L.), were the most common species to have increased in abundance in the study lakes, whereas burbot, Lota lota (L.), and vendace, Coregonus albula (L.), decreased, especially in highly eutrophic lakes. High total phosphorus and cyprinid dominance in lakes were found mainly in the most intensive agricultural regions in the western and southern parts of Finland.     

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。     

Fish fauna in a Protected Greek lake: biodiversity, introduced fish species over a 80-year period and their impacts on the ecosystem

Abstract –  Lake Pamvotis is a tertiary natural shallow lake located in the NW of Greece. For biogeographical reasons, it historically contained only four fish species: two endemics ( Phoxinellus epiroticus , Squalius pamvoticus ), one native to the West Greece ( Barbus albanicus ) and the ubiquitous Anguilla anguilla . These species were almost exclusively present in the lake before 1920, forming remarkable commercially exploited populations. From the 1930s through the 1990s, 20 species were introduced into the lake for purposes of eutrophication control or to enhance the fishery. These introductions, some of them accidental have led to the apparent decline, even loss, of the native species. During the last three decades the fish fauna of the lake has shifted from the native, clear-water species to a predominance of introduced species, mainly those adapted for turbid eutrophic water ( Rutilus panosi , Cyprinus carpio and Carassius gibelio , and several Asian cyprinids). The current fish assemblage in the lake is dominated by introduced species particularly the Mosquitofish ( Gambusia affinis ) and the Lourogobios ( Economidichthys pygmaeus ) in the littoral zone, the benthopelagic allogynogenetic Prussian carp ( C. gibelio) , and the opportunistic Trichonis roach ( R. panosi ), in the pelagic zone.     

巢湖后生浮游动物群落及不同湖区营养状态评价

为了给巢湖水质管理及富营养化防治提供科学依据，根据水系特征，在巢湖东、西湖区湖心、裕溪河出湖口、丰乐河、派河和南淝河共设置8个采样点，2013年12月至2014年11月共采样12次，分别代表冬季(12月-次年2月)、春季(3-5月)、夏季(6-8月)和秋季(9-11月)，对巢湖水体理化因子和后生浮游动物（枝角类、桡足类、轮虫）群落进行逐月周年调查。基于叶绿素(Chl-a)、总磷(TP)、总氮(TN)、化学需氧量(CODMn)、透明度(SD)等水体理化指标，运用综合营养状态指数(TLI)和生物多样性指数，对不同湖区受污染程度和营养状态进行综合评价。结果显示，巢湖共检出后生浮游动物42种（属），优势种矩形龟甲轮虫(Keratella quadrata)、萼花臂尾轮虫(Brachionus calyciflorus)为富营养化水体或有机质较多水体的常见种，不同季节的优势种存在较大差异；总体上，后生浮游动物全年平均丰度371.6 个/L（191.5~600.0 个/L）和全年平均生物量3.0 mg/L（2.0~4.6 mg/L）均呈现西半湖高于东半湖、夏秋季高于冬春季的分布特点；其群落结构也存在显著的季节差异和空间差异，矩形龟甲轮虫、萼花臂尾轮虫等是造成差异的主要种类。水温(WT)和Chl-a是影响枝角类丰度的重要因子，桡足类丰度与WT呈显著正相关，而轮虫丰度受TLI(∑)指数的显著影响。TLI(∑)指数均值为60.33（52.18~66.28），指示巢湖总体处于轻度至中度富营养化状态。Shannon-Wiener多样性指数和Margalef丰富度指数表明，巢湖总体处于中度污染状态，不同湖区水体具有明显的不均衡性。     

武汉城市湖泊水质及水体富营养化现状评价

为了判别武汉市典型城市湖泊汤逊湖、野芷湖、黄家湖和东野芷湖的水质状况,从2011年3月～2012年2月,对这四个湖泊进行了周年水质监测。采用了水体总氮、总磷、叶绿素a、透明度等参数,对水质现状、水体富营养化程度进行了综合分析。结果表明,该四湖的水质污染程度呈现明显的梯度。水体富营养化综合加权指数法评价表明,湖泊全年富营养化状态级别处于中营养到轻度富营养化之间。     

兴凯湖与小兴凯湖鱼类组成及差异分析

兴凯湖与小兴凯湖地处我国东北边陲,仅一岗之隔,但二者的生态环境差别很大,在小兴凯湖移植大银鱼Protosalanx hyalocraniu进行人工增殖没有取得很好效果的情况下,随泄洪水流入到兴凯湖中的大银鱼则很好地发展了自己的种群。为探讨兴凯湖与小兴凯湖鱼类组成的差异及其与大银鱼种群发展的关系,于2010年1月-12月对兴凯湖和小兴凯湖鱼类组成进行了调查。调查结果表明二者在鱼类种类组成上相似性仍较高,但在鱼类生物量组成上有明显差别。本次调查兴凯湖有鱼类56种,与历史数据比较基本没有减少,但新纪录3种：大麻哈鱼Oncorhynchus keta、梭鲈Lucioperca lucioperca和黑龙江泥鳅Misgurnus moloity（Dybowski）。小兴凯湖现有鱼类33种,比历史记载减少10种,东北Sarcocheilichthys lacustris、怀头鲶Silurus soldatovi和大银鱼为3个新纪录种;两湖的Sorenson指数为0.72。作为亚寒带的大型湖泊兴凯湖有着独特的水文和生态特点,大多数喜草生境种类在兴凯湖中的生物量都很低。本文探讨了兴凯湖与小兴凯湖鱼类组成差异与大银鱼种群发展的关系。     

兴凯湖与小兴凯湖鱼类组成及差异分析

兴凯湖与小兴凯湖地处我国东北边陲,仅一岗之隔,但二者的生态环境差别很大,在小兴凯湖移植大银鱼Protosalanx hyalocraniu进行人工增殖没有取得很好效果的情况下,随泄洪水流入到兴凯湖中的大银鱼则很好地发展了自己的种群。为探讨兴凯湖与小兴凯湖鱼类组成的差异及其与大银鱼种群发展的关系,于2010年1月-12月...     

以滆湖为例湖泊种植饲料水草的养鱼效果研究

本研究以典型的浅水草型湖泊滆湖为对象,通过对几种水草营养成份的分析,草食性鱼类对这几种水草摄食程度的比较,发现草鱼、团头鲂最喜食的水草为苦草、轮叶黑藻和菹草。为促进这些饲料水草的繁茂,在湖区进行了这三种水草不同方法的种植及合理利用技术的试验。根据所得结果,提出了苦草刈割间隔期以23天为宜;通过割草养鱼试验,提出了蓄草养鱼的配套技术措施,并对滆湖网围养鱼的发展提出建议。     

涨渡湖渔业资源及鱼类多样性状况研究

武汉市新洲区涨渡湖渔业生产是以人工投放、天然生长为主,鱼类资源自然增殖为辅的粗放型管理模式进行。1992~2004年捕捞产量变幅范围为(3.69~50.61)×104kg,其中有9个年份变幅在10×104kg以上;产品收入变幅范围为(2.77~201.77)×104元,其中有6个年份变幅在50×104元以上。目前涨渡湖鱼类共有47种,与历史最高种数比较,下降了38.2%。渔获物组成中,放养鱼类占80%以上,人工放养是目前涨渡湖鱼类补充群体的主要来源;鱼类年龄结构简单,主要经济鱼类低龄化趋势严重;主要品种鲢、鳙的生长速度慢于同类湖泊。江湖隔绝和长期的人工增养殖生产作业方式,是导致涨渡湖鱼类区系逐渐简单化,鱼类多样性下降的重要原因。     

洋澜湖下湖鱼类中毒死亡原因分析

面积１．２３ｋｍ２的洋澜湖系鄂州城区唯一的湖泊，日接纳未经处理的工业废水与生活污水８万ｔ，水体高度富营养化。以化工厂等企业超标工业废水的点源污染严重，尤以氨氮污染突出，造成１９９５年夏天该湖下湖（水面６６７ｈｍ２）鱼类非离子氨中毒，死亡２０万ｋｇ左右。     

Role of small-scale fishing in Kompong Thom Province, Cambodia

ABSTRACT:   Household surveys of small-scale fishing were conducted in Svay Ear and Srey Rangit villages in Kompong Thom Province, Cambodia. Data were collected from 104 of 183 households and 105 of 140 households in Svay Ear and Srey Rangit, respectively. In both villages, almost all households conducted rice cultivation and approximately 75% of them also conducted fishing. Three fishing groups: (i) inside lake; (ii) around lake; and (iii) around village were observed in both villages, according to their main fishing grounds. The inside lake group conduct fishing only in Tonle Sap Lake which is located 30 km away from the villages. The around lake group fish in lakes, marshes and flooded forests adjacent to Tonle Sap Lake, which are more than 5 km from the villages. The around village group collects fish from rice fields and ponds located inside the villages and also in some streams, rivers and lakes adjacent to the villages. The distance to the fishing grounds is less than 5 km from the villages. Most fishing groups were the inside and around lake groups, which occupied 76.0 and 65.7% of Svay Ear and Srey Rangit, respectively. These two groups produced 80.6 and 69.7% of the respective village annual total fish catches. These two groups sold a large portion of their fish catches. Although previous reports indicated that small-scale fishing is for subsistence, present results indicated that small-scale fishing was commercially conducted and fishing was important as an income source.     

Ecosystem structure and functioning of Lake Taihu (China) and the impacts of fishing

Lake Taihu is the third largest freshwater lake in China and has provided local communities with valuable fisheries for centuries. However, we have only a limited knowledge of its ecosystem. In this study, a trophic model was constructed for the Lake Taihu ecosystem. This model was used to evaluate and analyze the food web structure and other properties of this ecosystem using data covering the period from 1991 to 1995. Using the model, we evaluated the impacts on local fisheries of various management scenarios comprising two basic management regimes: (1) setting fishing mortality for the top predator (large culters, Erythroculter mongolicus and Erythroculter ilishaeformis) to 0, 0.3, 0.6, 0.9 and 1.2, and (2) adjusting overall fishing effort to 0.25, 0.5, 0.75 and 1.25 times the current level. For both scenarios, fishery profit and cost were evaluated to provide an understanding of how components of the ecosystem interact. We identified possible causes of fishery overexploitation in the lake ecosystem and described the necessity of developing ecosystem-based management. The results showed that Lake Taihu had six theoretical trophic levels (TLs), with the trophic flows primarily occurring through the first five TLs. System properties such as transfer efficiency, Finn's index, Finn's mean length, connectance index, system omnivory index, primary production/respiration ratio, and net primary production all indicated that Lake Taihu was an immature, fairly simple ecosystem in which a relatively low fraction of total primary production was utilized. At the same time, the ecosystem was also experiencing high fishing pressure. Yet despite this, the low ascendency index (25.9%) and high system overhead ratio (74.1%) indicated that the system was highly developed and relatively stable, a condition that might result from the high degree of recycling in the system. Among the harvesting strategies considered, a strategy of either decreasing the fishing mortality of the top predator (large culters) to 0.3 or, alternatively, reducing the overall effort on the system by a factor of 0.75 appeared to be most effective at increasing the efficiency of the fisheries.     

长江下游浅水湖泊石臼湖鱼类资源现状及变化趋势

根据2012-2013年对石臼湖水质和鱼类资源开展的2次调查数据,研究石臼湖水质、鱼类资源现状及演变趋势。采用水质单因子评价方法、营养状态质量指数,结合经济合作与发展OECO富营养湖泊判断标准,研究石臼湖、姑溪河、塘沟河、清水河的水质和富营养化状况;通过商业捕捞的渔获物调查,收集石臼湖和姑溪河鱼类资源数据,分析河网区鱼类种类组成、渔获物结构等渔业资源现状。结果表明,石臼湖及毗邻水域存在一定程度的水污染,且湖区受水量变化影响低于河流区,总体水质状况符合地表水环境质量Ⅲ~Ⅳ类,为富营养状态。石臼湖分布鱼类110种,2012-2013年共调查到54种;其中,石臼湖38种,固城湖33种,姑溪河51种。石臼湖、固城湖和姑溪河主要经济鱼类(数量和重量均超过1%的种类)分别有13、11和9种。石臼湖鱼类主要以鲤[Cyprinus(Cyprinus)carpio]、鲫(Carassius auratus)、鲇(Silurus asotus)等适应静、缓流生境的鱼类为主,并以歺又鱼(Hemiculter leucisculus)、鲫、棒花鱼(Abbotina rivularis)等小型鱼类或小规格个体鱼类(1 000 g)为主;湖区天然渔业资源呈衰退趋势,由于和长江下游干流相通,姑溪河鱼类种类数高于湖区,但其生物量远低于湖区;渔业资源的分布状况与水质状况无明显相关性,与河湖的连通性有关;受枯水期水量偏少、上游和周边来水污染以及高密度水产养殖的影响,石臼湖水质出现氮、磷和有机污染物超标等问题。宜采取源头控污、限制养殖、渔民转产以及人工增殖等措施,保护石臼湖水质,恢复天然渔业资源。     

有机质对大型富营养化浅水湖泊沉积物磷吸附特征的影响

以大型浅水湖泊(太湖和巢湖)为研究对象,系统分析了沉积物有机质(OM)含量和组成、磷吸附参数、磷形态及间隙水溶解反应性磷(SRP)浓度在水平方向上的分布.吸附解吸平衡浓度(EPC0)与SRP浓度的比较结果表明,在太湖北部与巢湖南淝河入湖口等污染较严重的区域,沉积物仍表现出吸附磷的功能；OM与土壤有效磷(Olsen-P)、磷吸附指数和碱性磷酸酶活性均显著正相关,有机质分解所产生的小分子物质可增加磷的吸附容量；添加小分子有机质的室内模拟试验进一步证实了上述假设,糖类主要影响磷的吸附能,而氨基酸主要增加最大吸附量.有机质自身及其降解产物以不同方式影响沉积物对磷的吸附能力,并据此调节湖泊富营养化过程.     

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。     

太湖敞水区鱼类种间关系现状

太湖敞水区鱼类群落组成,除人工放流的种类外,河湖洄游性鱼类已基本消失,以湖鲚、银鱼、虾类和小型鲤科鱼类种群占绝对优势。８种优势种种间协调系数显示,湖鲚、银鱼类,白虾,似鲚、九州稣箴等相互关系较为密切,其中太硝新银鱼和寡齿新银鱼之间除产卵期有先后外,时空分布和食饵对象基本一致。     

太湖流域主要水系水环境特征分析与富营养化评价

对太湖流域苕溪、南溪、太湖、沿江和黄浦江5大水系水体环境特征进行2次全范围调查监测,在此基础上分析主要水系的水环境特征现状,并用模糊综合评价方法对主要水系的富营养化程度进行评价.结果表明,除苕溪和南溪水系外,太湖流域各水系水体透明度都较低,可能与部分水体泥沙含量较大有直接关系,但水体中藻类、有机物和水动力条件等可能也是影响透明度的因素;耗氧性有机污染物指标处于地表水Ⅳ类～Ⅴ类,且B/C(可生化性指标)比较高,分解利用引起水中溶解氧(DO)的快速下降.氮磷营养元素污染相对严重,基本处于地表Ⅴ类～劣Ⅴ类水平,且各水体中都以总磷(TP)污染最为突出.总氮(TN)和TP中分别主要以溶解无机氧( DIN)和PO43-的形式存在,其较高的浓度为藻类快速生长甚至爆发水华提供了必要条件.对污染指标主成分分析的结果表明,氮磷和有机物是流域水体污染的主要贡献指标.富营养化模糊综合评价结果表明,苕溪水系、南溪水系和太湖基本处于中度富营养化水平,而沿江水系和黄浦江水系基本处于重度富营养化水平.