银盘水电站鱼类资源现状和缓解工程影响的保护措施探讨

2009年6月和10月对乌江下游银盘水电站工程影响区域的鱼类现状进行了调查,共采集到鱼类77种,其中鲤科鱼类有45种,占种类数的58.44%,鳅科10种,占12.99%,鲿科11种,占14.29%。从彭水至白马,鲤科鱼类所占比例逐渐增大,鲿科鱼类所占比例逐渐减小。优势种类数量排在前10位的依次为瓦氏黄颡鱼、鱼歺又、宜昌鳅鮀、大鳍鳠、圆筒吻鮈、蛇鮈、吻鮈、鲫、粗唇鮠和泉水鱼,它们占影响区域江段总数量的80.04%;质量优势种类依次为瓦氏黄颡鱼、铜鱼、吻鮈、南方鲇、圆筒吻鮈、鲤、大鳍鳠、墨头鱼、鲫和歺鱼又,它们占影响区域江段总质量的73.83%。结合工程建设造成的大坝阻隔,库区江段生境萎缩或丧失,以及坝下江段水文情势变化加剧、气体过饱和、下泄水温低等可能对鱼类资源产生影响的因素分析,提出增殖放流、过鱼设施建设、改进消能方案以及优化调度规程等多项保护措施,达到保护鱼类资源、促使工程影响区的生态环境呈良性循环的目的。     

银盘水电站鱼类资源现状和缓解工程影响的保护措施探讨

2009年6月和10月对乌江下游银盘水电站工程影响区域的鱼类现状进行了调查,共采集到鱼类77种,其中鲤科鱼类有45种,占种类数的58.44%,鳅科10种,占12.99%,鲿科11种,占14.29%。从彭水至白马,鲤科鱼类所占比例逐渐增大,鲿科鱼类所占比例逐渐减小。优势种类数量排在前10位的依次为瓦氏黄颡鱼、鱼歺又、宜昌鳅鮀、大鳍鳠、圆筒吻鮈、蛇鮈、吻鮈、鲫、粗唇鮠和泉水鱼,它们占影响区域江段总数量的80.04%;质量优势种类依次为瓦氏黄颡鱼、铜鱼、吻鮈、南方鲇、圆筒吻鮈、鲤、大鳍鳠、墨头鱼、鲫和歺鱼又,它们占影响区域江段总质量的73.83%。结合工程建设造成的大坝阻隔,库区江段生境萎缩或丧失,以及坝下江段水文情势变化加剧、气体过饱和、下泄水温低等可能对鱼类资源产生影响的因素分析,提出增殖放流、过鱼设施建设、改进消能方案以及优化调度规程等多项保护措施,达到保护鱼类资源、促使工程影响区的生态环境呈良性循环的目的。     

应用于鱼道设计的新疆木扎提河斑重唇鱼的游泳能力测试

为了探究斑重唇鱼的游泳能力,给过鱼设施设计和鱼类游泳行为学研究提供基础参数,本研究以木扎提河野生斑重唇鱼(全长TL=12～16 cm)为研究对象,测定了其在(16.6±1.6)℃水温下的感应流速、临界游泳速度、爆发游泳速度及持续与耐久游泳能力。结果显示,斑重唇鱼感应流速为(0.18±0.02)m/s,相对感应流速为(1.40±0.23) BL/s (BL为体长);临界游泳速度为(1.02±0.15) m/s,相对临界游泳速度为(8.58±1.65) BL/s;爆发游泳速度为(1.39±0.17) m/s,相对爆发游泳速度为(10.92±1.86) BL/s;最大持续游泳速度为0.87 m/s,最大耐久游泳速度为1.37 m/s,与平均爆发游泳速度相近。其持续游泳时间与流速呈负相关(l g T=?5:136X+8:504)。当以斑重唇鱼为主要过鱼对象时,建议为吸引鱼类进入鱼道,进口流速设计为1.02～1.39 m/s,休息池主流设计为0.20～1.02 m/s,鱼道竖缝处流速宜低于0.85 m/s。鱼道长度为1 000 m时,鱼道内平均水流速度应低于0.78m/s。本研究结果可为新疆木扎提河流域鱼类游泳能力研究提供参考,对保护日益减少的鱼类资源具有重要意义。     

科技动态

生长在广西河池地区河流中的4个鱼类新种,已被中国科学院水生生物研究所分别命名为短身金线鲃、郑氏繐唇鲃、伍氏异盘鮈和后鳍薄鳅。     

应用于鱼道设计的新疆木扎提河斑重唇鱼的游泳能力测试

为了探究斑重唇鱼的游泳能力，给过鱼设施设计和鱼类游泳行为学研究提供基础参数，本研究以木扎提河野生斑重唇鱼(全长TL=12~16 cm)为研究对象，测定了其在(16.6±1.6) ℃水温下的感应流速、临界游泳速度、爆发游泳速度及持续与耐久游泳能力。结果显示，斑重唇鱼感应流速为(0.18±0.02)m/s，相对感应流速为(1.40±0.23) BL/s (BL为体长)；临界游泳速度为(1.02±0.15) m/s，相对临界游泳速度为(8.58±1.65) BL/s；爆发游泳速度为(1.39±0.17) m/s，相对爆发游泳速度为(10.92±1.86) BL/s；最大持续游泳速度为0.87 m/s，最大耐久游泳速度为1.37 m/s，与平均爆发游泳速度相近。其持续游泳时间与流速呈负相关(${\rm lg}T = - 5.136{{X}} + 8.504$)。当以斑重唇鱼为主要过鱼对象时，建议为吸引鱼类进入鱼道，进口流速设计为1.02~1.39 m/s，休息池主流设计为0.20~1.02 m/s，鱼道竖缝处流速宜低于0.85 m/s。鱼道长度为1 000 m时，鱼道内平均水流速度应低于0.78 m/s。本研究结果可为新疆木扎提河流域鱼类游泳能力研究提供参考，对保护日益减少的鱼类资源具有重要意义。     

黑水河鱼类优先保护次序的定量分析

在金沙江下游干流大规模水电开发的背景下，干流开发与支流保护是生态环境保护的有效措施；黑水河是白鹤滩库区鱼类的优先保护支流，确定其鱼类优先保护次序和保护物种是进行鱼类栖息地修复和保护工作的首要任务和前提基础。在野外调查和查阅相关文献资料的基础上，运用濒危系数、遗传价值系数和物种价值系数对黑水河35种鱼类进行优先保护次序的定量分析，并结合黑水河栖息地实际情况，确定保护目标鱼类。结果显示，达到黑水河一级保护的鱼类只有1种，为长江上游特有鱼类长薄鳅（Leptobotia elongata）；达到二级保护的种类有12种，其中昆明裂腹鱼（Schizothorax grahami）、黄石爬鮡（Euchiloglanis kishinouyei）、短须裂腹鱼（Schizothorax wangchiachii）和长鳍吻鮈（Rhinogobio ventralis）为长江上游特有鱼类；处于三级保护的鱼类有17种，其中钝吻棒花鱼（Abbottina obtusirostris）和张氏?（Hemiculter tchangi）是长江上游特有鱼类；四级保护鱼类有5种，其中短体副鳅（Paracobitis potanini）为长江上游特有鱼类，评价结果基本反映了黑水河鱼类的实际情况。结合白鹤滩水库蓄水后黑水河栖息地生境改变的情况，最终确定昆明裂腹鱼、黄石爬鮡、短须裂腹鱼为黑水河栖息地修复和保护的目标鱼类，长薄鳅和长鳍吻鮈为备选保护鱼类。     

科技

<正>长鳍吻鮈人工繁育技术获突破近日,长江水产研究所"长鳍吻鮈人工驯养繁殖技术研究"阶段性成果通过了专家现场验收。验收专家组认为,该阶段性成果首次实现封闭循环水系统中长鳍吻鮈亲鱼培育成熟、人工催产成功、小批量鱼苗开口摄食并正常生长的全技术过程,是长鳍吻鮈人工繁育技术的重要突破。长鳍吻鮈属于鲤形目鲤科鮈亚科吻鮈属,是我国长江上游的特有鱼类,也是重要的经济鱼类。近年来受水电工程、过渡捕捞等因素的影响,鱼类资源急剧下降,多个水电工程将长鳍     

野生长鳍吻鮈驯化养殖技术初探

正在野生鱼类的养殖、繁育过程中,野生鱼类的收集驯养是实现养殖乃至繁殖的首要关键因素。作者团队为了有效保护长鳍吻鮈物种资源,对野生长鳍吻鮈进行了人工驯养研究,结果显示:野生长鳍吻鮈在驯养70d能主动摄食沉性配合商品饲料,存活率为40%～50%。     

银盘电站蓄水前后乌江下游产漂流性卵鱼类自然繁殖变化

为了探究水电开发对流域鱼类资源的影响,遏制生物多样性衰退的趋势,2009-2015年5-7月对乌江下游干流漂流性鱼卵进行阶段性调查,初步分析银盘电站蓄水前后产漂流性卵鱼类的自然繁殖变化。结果表明,调查期间共采集到鱼卵12种,包括犁头鳅(Lepturichthys fimbriata)、中华金沙鳅(Jinsha sinensis)、中华沙鳅(Botia superciliaris)、圆筒吻鮈(Rhinogobio cylindricus)、吻鮈(Rhinogobio typus)、长鳍吻鮈(Rhinogobio ventralis)、蛇鮈(Saurogobio dabryi)、花斑副沙鳅(Parabotia fasciata)、铜鱼(Coreius heterodon)、中华倒刺鲃(Spinibarbus sinensis)、翘嘴鲌(Culter alburnus)和蒙古鲌(Culter mongolicus)。漂流性鱼卵年资源量为1 012.99万～18 673.97万粒,鱼类产卵场自上而下分布有彭水、高谷、江口(杨家沱)、武隆(石鼻子)、土坎(桃子沟)、羊角共6处。银盘电站蓄水后,乌江下游产漂流性卵鱼类的自然繁殖较蓄水前发生了显著变化。种类组成中,典型的流水生境繁殖类群减少,缓静水生境繁殖类群增加;产卵规模显著下降,以长鳍吻鮈、铜鱼、圆筒吻鮈、中华金沙鳅的减少尤为显著;产卵场减少并逐步往坝下压缩,数量由6处减少至3处,长度由35 km减少至18 km,位于银盘库区的彭水、高谷产卵场消失,江口产卵场规模显著缩小。产漂流性卵鱼类的大规模产卵都在涨水时发生,不同种类产卵对水文条件的要求有所差异,大坝建设引起的栖息地萎缩和水文情势改变是导致乌江下游漂流性卵鱼类早期资源衰退的主要原因。建议采用水库生态调度补偿措施,通过合理下泄生态流量,加大脉冲流量和流水江段长度来满足重要鱼类的繁殖和早期发育需求,并结合人工增殖放流、鱼类基础监测和生态学研究等综合手段,强化乌江下游鱼类资源的生态修复。     

长鳍吻鮈的核型

<正> 鮈亚科(Gobioninae)吻鮈属(Rhi-nogobio)鱼类在我国共有4种,作者报道过该属吻鮈和圆简吻鮈的核型,本文报道长鳍吻鮈(Rhinogobio ventralis Sau-vage et Dabry)的核型。材料与方法实验鱼4尾(2尾♂、2尾♀),均采自长江的宜昌江段。活鱼注射秋水仙碱溶液(2微克/每克体重)后继续在江水中养2～4小时。取出肾脏,在RPMI 1640培养液中制备细胞悬液。用常规空气干燥法和Giemsa染色制备染色体玻片标本。在油浸     

Effects of dissolved carbon dioxide on energy metabolism and stress responses in European seabass (Dicentrarchus labrax)

Elevated carbon dioxide concentrations reduce feed intake and growth in several fish species and induce stress responses. In this study, the effects of moderately elevated CO₂ levels on performance, energy partitioning, swimming activity and stress response in European seabass were assessed. European seabass (140.0 g) were reared under two levels of CO₂ (1.6 and 7.0 mg L^?1) and two feeding levels (FLs) (maintenance and satiation) for 60 days, and fish swimming speed was recorded. At the end of the experiment, fish were subjected to an acute stress test. Blood cortisol, glucose and lactate were analysed. Energy and nitrogen balances were quantified based on measurements of body composition and digestibility coefficients. Moderately elevated chronic CO₂ level did neither affect energy requirements for maintenance nor the utilization of digestible energy for growth. However, swimming activity data suggests that FL dependent alterations in energy partitioning took place. Blood cortisol values after the acute stress were affected by additional CO₂ exposure and this effect was also dependent on FL. The elevated CO₂ exposure of 7.0 mg L^?1 appears to act as a chronic stressor as adaptive responses took place, however, this CO₂ exposure seems to be still within the allostatic load of the fish.     

新疆渭干河流域鱼类资源现状

2019年5月、8月和11月,在上、中、下游共设5个采样点,采用单层刺网(网目1、2、3 cm,网长20、30、40 m)和地笼网(开口40 cm×40 cm,长8 m)调查新疆天山南麓中段塔里木河流域九大水系之一的渭干河(N 41°06′~42°42′,E 80°40′~84°10′)的鱼类资源状况。调查共采集鱼类1864尾,总质量47869.05 g,隶属3目6科15属19种。土著鱼类1目4属8种,其中鲤科鱼类3属5种,鳅科鱼类1属3种。外来鱼类3目11属11种,其中鲤科鱼类6属6种,鳅科、鲈科、塘鳢科、虾虎鱼科、鲇科各1属1种。8月捕获鱼类种类最多,共17种。5月捕获渔获物数量和质量最大,占总渔获物数量的38.41%,占总渔获物质量的64.12%。渭干河优势种为斑重唇鱼、、河鲈和麦穗鱼。渭干河上游、下游河段鱼类种类稀少,群落多样性低。与历史数据相比,扁嘴裂腹鱼和重唇裂腹鱼未采集到,其他土著鱼类捕获量低,外来鱼类捕获量大。通过聚类分析,将5个采样点鱼类分为2类,经过单因子相似性分析得出,这2个群聚之间差异不显著(P>0.05)。将渭干河4种优势种和8种常见种分为2类,经过单因子相似性分析得出,这2个群聚之间差异显著(P<0.05)。外来鱼类入侵和水利工程是影响渭干河鱼类群落的主要因子。     

Phenotypical and genotypical characterization of Shewanella putrefaciens strains isolated from diseased freshwater fish

Between 2007 and 2012, a variety of disease outbreaks most often characterized by skin disorders were observed among different species of freshwater fish in Poland. In most cases, the clinical signs included focally necrotized gills, necrotic skin lesions or ulcers. Internally, haemorrhages, oedematous kidney and abnormal spleen enlargement were generally noted. The disorders were accompanied by increased mortality. Most of the problems concerned cultured common carp Cyprinus carpio L. and rainbow trout Oncorhynchus mykiss (Walbaum). Fish have been examined from a number of these farms, and additionally, the wild and ornamental fish with similar clinical signs of diseases were also tested. Bacteria were isolated consistently from lesions and internal organs. They had characteristic orange-pigmented colonies which grew in pure culture or constituted 55–95% of total bacterial flora. One hundred and eighteen isolates were collected and biochemically identified as Shewanella putrefaciens group, and this was confirmed by sequencing. Challenge tests confirmed the pathogenicity of these bacteria. This is the first report characterizing and describing S. putrefaciens as a pathogen of different species of freshwater fish in Europe.     

Fish Processing By-Products as a Potential Source of Gelatin: A Review

ABSTRACT

The current practice of fish processing generates large amounts of by-products, which can account for up to three-quarters of the total fish weight. Despite the presence of several valuable components in the fish processing discards, the latter are usually dumped into landfills or at sea, having potentially harmful environmental effects or end up as low commercial value products (e.g., white fish meal). Still, fish processing by-products can be considered as an alternative raw material for the preparation of high-protein ingredients, especially for the production of food grade gelatin due to the presence of large amounts of collagen in fish skins, scales, and bones. Although fish gelatin is an alternative to the commercially available mammalian gelatins, its production on a large commercial scale has been hampered, mainly, due to the inferior quality characteristics compared to its mammalian counterparts. This review article summarizes and highlights the potential utilization of by-products generated during fish processing for gelatin extraction. Furthermore, several technical challenges and directions of ongoing research are discussed.     

Bacteriocins and their applications for the treatment of bacterial diseases in aquaculture: a review

Aquaculture is one of the fastest growing food producing sectors in the world. The increase in the world population requires faster growth in aquaculture for better food availability and to overcome malnutrition. But this worldwide growth of aquaculture is overwhelmed by catastrophic fish diseases and spoilage during cultivation and preservation problems caused by pathogenic bacteria. Various remedies are available for food preservation and also from the bacterial diseases in the fish production. Due to the emergence of antibiotic resistance and adverse effects, an alternative to antibiotic is the need of the hour. The proteins such as bacteriocins, i.e. ribosomally synthesized antimicrobial peptides (AMPs) and possess antagonistic against closely related and other bacteria. These proteins are produced by most lineages of bacteria which are playing key roles in recognition and possess a cognate immunity system for self‐protection as well as host protection from infections. These proteins are potent immunomodulators with broad spectrum inhibition properties which are further used as novel therapeutic agents. In this review, we have tried to summarize the bacteriocins on the basis of their classifications, structural and functional attributes, mode of actions, bacteriocins isolated from fish and gut microbiota and presence of beneficiary bacteria in the fish gut. Further, this study highlighted where further research is a prerequisite to increase our basic understanding and search for novel bacteriocins to elucidate the proteins/peptides having antimicrobial properties for disease control in aquaculture as an alternative to antibiotics.     

Regulating fish movements in the Single European Market: the scope for more restrictive measures under national law

Abstract  Substantial alterations to the legal controls over fish movements have been necessary to implement the Single European Market which came into force on 1 January 1993. This seeks to liberalize trade in fish and fish products whilst avoiding ecological damage, the spread of disease and the commercial damage this may cause. The new regime governing fish movements into and within the European Union under Directive 91/67/EEC, as implemented in England and Wales, is described. Remaining national provisions based on ecological concerns (principally, section 30 of the Salmon and Freshwater Fisheries Act 1975) are examined. Derogations from the principle of freedom of trade within the European Union on environmental protection grounds are assessed, and the interaction between legal restrictions based on pathological and ecological grounds is discussed.     

Changes in Red Hake (Urophycis chuss) Muscle Induced by Different Freezing Strategies

The effect of single and double freezing at ?20°C on fresh and aged red hake with two different holding times of the thawed fillets between the first and second freezing treatments was determined. In addition, twice-frozen fresh red hake was treated with two antioxidation systems to assess their effectiveness in reducing lipid oxidation. Fresh, untreated red hake at 0 time was used for comparison. Significant dimethylamine (DMA) production occurred with all frozen samples, and the differences were not marked after 7-month storage. With a storage time of 3 months, however, there were differences between the treatments in both the fresh and aged samples with the once-frozen sample producing the least DMA, the twice-frozen sample with the 24-h holding time between freezings the most, and the twice-frozen sample with a 6-h holding time between freezings giving intermediate values. All samples showed a greater than 50% loss in protein solubility as determined by lithium chloride extraction after 3 months of storage, and the protein solubility declined further when samples were tested at 7 months. Samples with the best (once-frozen fresh) and worst (twice-frozen with 24-h holding time between freezings of 5-day aged muscle) treatments had the highest thiobarbituric acid-reactive substances (TBARS) values. Both antioxidant treatments were effective in reducing TBARS development.     

淡水鱼在保温鱼箱中贮存期限的研究

我国养殖淡水鱼类居世界首位。特别是近年来淡水鱼的产量迅速增长,淡水鱼从生产到流通上市过程中的保鲜问题日趋重要。以往淡水鱼的贮运除活鱼车运输外,大多采用传统的木桶、竹篰、蒲包等落后的包装容器,由于保温条件差,鱼体受挤压,鱼货容易腐败变质。保温鱼箱是近年来渔业生产上使用的新型包装容器,从目前使用于海水鱼的情况来看,它具有良好的保鲜效果。为了进一步开拓保温鱼箱在淡水鱼流通领域中的应用,我们选用了上海市水产供销公司研制的8B-3型塑料保温鱼箱,以养殖     

Catch‐related fish injury and catch efficiency of stow‐net‐based fish recovery installations for fish‐monitoring at hydropower plants

Hydropower‐related damage to fish remains a great challenge, making objective monitoring of turbine‐related fish injury a necessity. The catch of fish at turbine outlets is currently realised by net fishing, but potential catch‐related injuries are largely unknown. Catch efficiency and fish‐friendliness in relation to fish handling, exposure time, floating debris and fish biomass of four fish recovery installations were assessed using seven species. Highly species‐specific lethal and sublethal effects were observed. Exposure time had the strongest effects on catch‐related damage, being up to 150‐fold increase after 12 hr compared to 1 hr. Up to 84% mortality occurred in the most sensitive species Thymallus thymallus L. Besides exposure time, higher current speed and biomass within the net resulted in greater fish damage. To minimise catch‐related effects, keeping emptying periods <1–2 hr and considering the effects of current speed, fish and debris biomass are crucial to increase data comparability among studies.