气候变化对鲑鳟鱼类栖息环境及相关生物学的影响

鲑鳟鱼类作为对温度和周围环境比较敏感的冷水性鱼类，气候变化尤其是全球温度升高引起环境的相关变化对其影响明显。本文针对国内外有关气候变化对鲑鳟鱼类栖息地及相关生物学影响的研究情况，先从从栖息地环境方面阐述了气候变化对水生生物的影响，又从温度、CO2浓度、降雨量及酸雨的增加、紫外线辐射增强和鱼病的传播等方面探讨气候变化对鲑鳟鱼类生物学方面的影响。同时指出目前研究中存在的地域局限性和缺乏评价标准的相关问题，并就存在的问题给出建议，提出了今后重点关注和尚待研究领域。     

电厂温排水对水生生物影响评价综述

总结温排水对水生生物和生态系统的一般性影响;介绍我国和美国4个不同环境背景的大型电厂温排水对当地水生生物的影响;分析厂址特定因素和环境背景的影响;讨论电厂温排水影响评价存在的问题。(1)温排水可能会影响水生生物的生长、生存和繁殖,改变群落的多样性和丰度,并可能导致栖息地的变化,但影响性质和程度各不相同;(2)温排水对水生生物的潜在影响程度与厂址特定因素包括地理位置、受纳水体是海水还是淡水、受纳水体的体积、水交换速率、生物栖息地等密切相关;(3)为了准确评价温排水的影响,我国首先应根据不同海域、流域或湖泊的特点,选择出代表性重要水生生物并进行热影响研究,为不同流域、湖泊、海域温度基准的制定奠定基础;应尽快制定温排水环境影响评价导则,使得温排水限值能够满足国家水体质量标准,确保受纳水体中平衡土著的贝类、鱼类和野生生物种群的生长和繁育,并且已考虑了温排水与所有其他对物种重要影响(包括杀生剂的影响、取水卷吸效应的影响、过度捕捞、其他污染源的排放等)的累积影响。     

热排水对水环境影响讨论会在宁召开

由水电部和世界卫生组织联合举办的热排水对水环境影响学术讨论会于1986年10月20～25日在南京召开。来自电力、水产系统二十八个单位的五十多位中、外代表出席了会议。与会者向大会宣读了有关热排放对水域环境及水生生物的影响，电厂冷却系统的水工设计和热排放标准的制订等研究报告，并从生理生态、工程设计、项目管理等不同角度展开了充分的讨论。     

水生生物对重金属的吸收和排放研究进展

综述了重金属在水生生物体内吸收与排放的研究状况,分析了影响重金属离子在水生生物体内吸收、积累与排出的因素;对未来的研究工作进行了展望;希望能为解决重金属对生态环境的污染提供参考。     

气候变化对鲑鳟鱼类栖息环境及相关生物学的影响

鲑鳟鱼类作为对温度和周围环境比较敏感的冷水性鱼类，气候变化尤其是全球温度升高引起环境的相关变化对其影响明显。本文针对国内外有关气候变化对鲑鳟鱼类栖息地及相关生物学影响的研究情况，先从从栖息地环境方面阐述了气候变化对水生生物的影响，又从温度、CO2浓度、降雨量及酸雨的增加、紫外线辐射增强和鱼病的传播等方面探讨气候变化对鲑...     

水生生物环境丰容技术及其应用研究进展

水生生物作为人类生活的重要组成部分，其在养殖、运输以及展示等过程中福利水平低下现象层出不穷，寻求合适的方法来解决水生生物福利低下的问题，成为保障并提升水生生物福利的一大重要工作。环境丰容作为一项能够通过对圈养动物生存环境进行优化，提升圈养动物福利水平，使得圈养动物获得生理和心理健康，展示其自然行为的技术，成为保障和提升水生生物福利的一个重要手段。目前，与国外相比，国内对水生生物环境丰容技术的研究还处于起步阶段，如何利用环境丰容技术改善水生生物的生存环境，保障并提升水生生物福利水平日益成为研究热点。为此，本文综述了环境丰容的定义、发展历程、环境丰容与动物福利的关系以及在水生生物中的4种主要环境丰容技术。同时，就水生生物环境丰容技术存在的问题进行讨论并提出建议，以期为水生生物环境丰容提供更多方案参考和理论支撑。     

中国水生生物资源养护行动纲要

我国海域辽阔，江河湖泊众多，为水生生物提供了良好的繁衍空间和生存条件。受独特的气候、地理及历史等因素的影响，我国水生生物具有特有程度高、孑遗物种数量大、生态系统类型齐全等特点。我国现有水生生物2万多种，在世界生物多样性中占有重要地位。以水生生物为主体的水生生态系统，在维系自然界物质循环、净化环境、缓解温室效应等方面发挥着重要作用。丰富的水生生物是人类重要的食物蛋白来源和渔业发展的物质基础。养护和合理利用水生生物资源对促进渔业可持续发展、维护国家生态安全具有重要意义。为全面贯彻落实科学发展观，切实加强国家生态建设，依法保护和合理利用水生生物资源，实施可持续发展战略，根据新阶段、新时期和市场经济条件下水生生物资源养护管理工作的要求，制定本纲要。     

有益微生物在水产养殖病害防治中的应用

水产养殖经过几年的浮沉，健康养殖工程技术已逐渐成为研究与生产的热点，营造良好水生养殖环境作为健康养殖工程的重要组成部分，正日愈为人们所认识和提倡。笔者近年来对如何应用有益微生物营造良好水生养殖环境，达到防治病害、健康养殖的目的进行了一些探讨研究，本文就此作一阐述。     

水生动物进口风险分析

<正>《OIE水生动物卫生法典》(简称《水生法典》)制定了改善世界各地水生动物健康和养殖鱼类福利的卫生标准,以及国际贸易中水生动物(两栖动物、甲壳动物、鱼类和软体动物)及其制品应遵循的标准。2014年5月第82界OIE成员国大会对《水生法典》进行了部分修改。新修订的《水生法典》中有关水生动物进口风险分析与原来有很大不同,现将有关内容介绍如下,供水生动物防疫工作者参考。     

火电厂冷却水体水生态热影响及渔业管理意见

本文叙述了火电厂热排水输入到水库、湖泊后，对冷却水体理化特性、饵料生物及鱼类产生的影响，并结合渔业生产管理实践，提出了加强“热影响”的基础理论研究、制定热排放标准、实行生态系统的人工定向改造及开展生态工作利用意见。     

Using the Judas technique to locate and remove wintertime aggregations of invasive common carp

Abstract Radio‐ and acoustic telemetry in three Midwestern lakes demonstrated that common carp, Cyprinus carpio L., aggregate as water temperatures descend below 10 °C. Particularly dense aggregations formed at temperatures <5 °C, and once located, these aggregations could be removed with an efficiency of up to 94% using seine nets. Carp aggregated just below the surface of the ice (approximately 1.5 m) and rarely descended to warmer waters, which extended down to 10 m. Although aggregations consistently formed close to shore, their locations could not be explained by temperature or dissolved oxygen. The aggregations also moved frequently, making radio‐tagged fish invaluable to locate them. Coldwater aggregations of carp may reflect a type of shoaling behaviour and can be exploited with the aid of radio‐tagged (Judas) fish to control this invasive fish effectively. Similar approaches might be developed for other gregarious invasive fishes.     

鱼类消化酶活性与其体长、体重和水质的相关性研究

对主养草鱼(Ctenopharyngodon idellus)池塘中4种鱼类消化器官的胃蛋白酶、胰蛋白酶、脂肪酶和淀粉酶的活性与鱼体长、体重及主要水质指标的相关性进行了研究。结果显示,草鱼肠道和肝胰脏的胃蛋白酶与水温具有显著正相关(P<0.05),而草鱼肠道胰蛋白酶、肠道和肝胰脏的脂肪酶以及鲢(Hypophthalmichthys molitrix)肝胰脏中淀粉酶与水温呈负相关(P>0.05)。4种鱼的消化酶活性与总氮和总磷呈正相关。匙吻鲟(Polyodon spathula)的脂肪酶和淀粉酶活性与化学耗氧量呈负相关;除鲢外,其他3种鱼的胃蛋白酶活性均与水体硬度和碱度呈正相关,而胰蛋白酶、脂肪酶和淀粉酶均与水体硬度和碱度呈负相关。草鱼和鳙(Aristichthys nobilis)肠道胰蛋白酶、脂肪酶和淀粉酶以及匙吻鲟消化道和肝脏胰蛋白酶与鱼的体长、体重均具有显著的正相关。     

鲢、鳙、草鱼摄食节律和日摄食率的初步研究

本文报道了鲢、鳙和草鱼的昼夜摄食节律和日摄食率，并对影响摄食节律和摄食强度的环境因子进行了初步探讨。试验的结果表明，这三种鱼都有明显的摄食节律。鲢、鳙鱼的饱满指数在每天4时最低，天亮前后开始升高，8时起明显升高，12时至20时是一天中的最高阶段，20时以后逐渐下降，午夜24时后，大约有6小时停食。草鱼的饱满指数也是以每天4时最低，12时和20时分别出现两个摄食高峰，两个高峰之间，即16时左右摄食强度有一个低落的阶段。试验也揭示了这三种鱼的日摄食率，即每天按单位体重的进食量。按日平均饱满指数法测计，鲢鱼日摄食率的最低值为5．6％，最高值为16．8％，平均为11．4％；鳙鱼的日摄食率最低值为2．5％，最高值为16．4％，平均值为6．7％；草鱼的日摄食率的最低值为26．3％，最高值为49．9％，平均值为38．6％。在全年中三种鱼的日摄食率都以在7、8月份为最高，这就是鲢、鳙、草鱼一年中摄食的最旺盛期。     

Response of fish membranes to environmental temperature

The effect of temperature on fluidity, fatty acid and molecular species composition of liver and brain phospholipids in fish adapted or exposed to extreme temperatures was investigated. Membranes from cold-adapted fish were more fluid than those from warm-adapted fish. Ability to control membrane fluidity according to temperature appears in early ontogenesis and is first evident in swim-up fry of carp. Red blood cells as well as neurons of adult carp can continuously adjust the fluidity of their external membranes to changing temperatures. Segregation of choline and ethanolamine phosphoglycerides from livers of fish adapted to a cold/warm environment showed an accumulation of molecular species containing a monoenic fatty acid in position sn-1 and a polyenic fatty acid in position sn-2 of the molecule in cold conditions. Model experiments using mixtures of synthetic 18:1/22:6 phoshatidylethanolamines and 16:0/18:1 phosphatidylcholines demonstrated the involvement of these molecular species in rendering the membranes less packed (more fluid) during adaptation to reduced temperatures.     

Variation in the distribution of yellowfin sole Limanda aspera larvae in warm and cold years in the eastern Bering Sea

Multiyear periods of relatively cold temperatures (2007–2013) and warm temperatures (2001–2005 and 2014–2018) altered the eastern Bering Sea ecosystem, affecting ocean currents and wind patterns, plankton community, and spatial distribution of fishes. Yellowfin sole Limanda aspera larvae were collected from the inner domain (≤50 m depth) of the eastern Bering Sea among four warm years (2002, 2004, 2005, 2016), an average year (2006), and three cold years (2007, 2010, 2012). Spatial distribution and density of larvae among those years was analyzed using generalized additive models that included timing of sea-ice retreat, areal coverage of water ≤0°C, and water temperature as covariates. Analyses indicated a combination of temperature effects on the location and timing of spawning, and on egg and larval survival, may explain the variation in larval density and distribution among years. During warm years, higher density and wider spatial distribution of larvae may be due to earlier spawning, an expansion of the spawning area, and higher egg and larvae survival due to favorable temperatures. Larval distribution contracted shoreward, and density was lower during cold conditions and was likely due to fish spawning closer to shore to remain in preferred temperatures, later spawning, and increased mortality. Predicted drift trajectories from spawning areas showed that larvae would reach nursery grounds in most years. Years when the drift period was longer than the pelagic phase of the larvae occurred during both warm and cold conditions indicating that settlement outside of nursery areas could happen during either temperature condition.     

鱼类对溶解气体过饱和水体的敏感性分析

大坝泄洪可携带大量空气进入水中,导致下游河道出现溶解气体过饱和,给水生生物特别是鱼类的生存造成威胁。通过自行设计的室内试验装置,研究了影响溶解气体过饱和度的因素及不同鱼类对气体溶解过饱和的敏感性。鱼类暴露在溶解气体过饱和环境中易出现突眼、充血和气泡等气泡病症状。鲢、鳙和鳊在溶解气体含量高的水体中容易患气泡病,草鱼和鲫稍次,基本可以忽略溶解气体过饱和对黄颡鱼和鲶的影响。     

Growth induction of common carp, Cyprinus carpio L., fry as a function of plankton density and improved water quality

Abstract. One hundred and ninety-eight fry of common carp, Cyprinus carpio L., were reared in outdoor tanks containing 9580 1 of water under five management schemes — separate live-food system (LF), intermediate system (I), static manured system (M), manured system with water exchange (EM) and supplementary food system (SF) — in triplicate for a growing period of 90 days. Examination of frequency distribution of different weight groups of fishes at the time of harvest showed a maximum proportion of larger and smaller fishes in the live-food and supplementary food system, respectively. Maximum growth and production of common carp in the LF treatment was the consequence of greater abundance of plankton food and improvement of water quality expressed in terms of higher values of pH and DO and lower values of COD and BOD.     

Projecting future habitat quality of three midwestern reservoir fishes under warming conditions

Rising temperatures caused by climate change are likely to affect cool‐water and warm‐water fishes differently. Yet, forecasts of anticipated temperature effects on fishes of different thermal guilds are lacking, especially in freshwater ecosystems. Towards this end, we used spatially explicit, growth rate potential (GRP) models to project changes in seasonal habitat quality for a warm‐water piscivore (largemouth bass Micropterus salmoides), a cool‐water piscivore (walleye Sander vitreus) and a hybrid piscivore (saugeye S. vitreus × S. canadensis) in two Midwestern reservoirs. We assessed habitat quality for two periods (early and middle 21st century) under two realistic greenhouse gas emission scenarios (a mid‐century emissions peak and a rapid continuous increase in emissions). Largemouth bass were projected to experience enhanced or slightly reduced habitat during all seasons, and throughout the mid‐21st century. By contrast, walleye habitat was projected to decline with anticipated warming, except during the spring in the smaller of our two study reservoirs and during the fall in the larger of our two study reservoirs. Saugeye habitat was projected to either increase modestly or decline slightly during the spring and fall and declines in habitat quality and quantity that were smaller than those for walleye were identified during summer. Collectively, our findings indicate that climate warming will differentially alter habitat suitability for reservoir piscivores, favouring warm‐water species over cool‐water species. We expect these changes in habitat quality to impact the dynamics of reservoir fish populations to varying degrees necessitating the consideration of climate when making future management decisions.     

Seasonal movements of non‐native lake trout in a connected lake and river system

Abstract Non‐native lake trout, Salvelinus namaycush (Walbaum), threaten native salmonid populations in the western United States. Effective management of lake trout requires understanding movements within connected lake and river systems. This study determined the seasonal movements of subadult lake trout in the Flathead River upstream of Flathead Lake, Montana, USA using radio telemetry. The spatiotemporal distribution of lake trout in the river was related to water temperature. Lake trout were detected in the river primarily during autumn, winter and spring, when water temperatures were cool. By contrast, fewer were detected when temperatures were warmest during summer and during high spring flows. Downriver movements to Flathead Lake occurred throughout autumn and winter when water temperature decreased below 5 °C, and in late spring as water temperature rose towards 15 °C and river discharge declined following spring runoff. Upriver movements occurred primarily in October, which coincided with migrations of prey fishes. These results suggest that lake trout are capable of moving throughout connected river and lake systems (up to 230 km) and that warm water temperatures function as an impediment to occupancy of the river during summer. Controlling source populations and maintaining natural water temperatures may be effective management strategies for reducing the spread of non‐native lake trout.     

Relationships among invasive common carp,native fishes and physicochemical characteristics in upper Midwest (USA) lakes

Abstract – Common carp Cyprinus carpio is a widespread invasive species that, in high abundance, can impose numerous deleterious effects in aquatic ecosystems. Common carp increase turbidity and nutrient availability while reducing invertebrate prey resources and aquatic macrophytes, transforming shallow lakes from the clear‐ to turbid‐water state. However, potential effects of common carp on native fish communities have received limited attention. We evaluated the relationships among relative abundances of nine native fishes and common carp for 81 lakes in eastern South Dakota and their associated physicochemical characteristics. Inverse threshold relationships among relative abundances of native fishes and common carp were identified for black bullhead Ameiurus melas, black crappie Pomoxis nigromaculatus, bluegill Lepomis macrochirus, white bass Morone chrysops and northern pike Esox lucius, while marginally significant relationships were detected for largemouth bass Micropterus salmoides and smallmouth bass M. dolomieu. Lakes where common carp relative abundance exceeded 0.6 fish per net night had low abundance of native fishes, whereas lower abundance of common carp resulted in variable abundance of native fishes. Lakes with abundance of common carp surpassing 0.6 fish per net night were also characterised by larger surface areas and watersheds and impaired water quality (higher dissolved solids and chlorophyll a concentrations and lower secchi depth). Our results are consistent with the biotic‐abiotic constraining hypothesis that proposes biotic factors can regulate fish populations regardless of abiotic conditions. Thus, common carp abundance may need to be reduced and sustained below ecological thresholds to improve water quality and increase abundance of native fishes.