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。     

Atlantic salmon in a rapidly changing environment—Facing the challenges of reduced marine survival and climate change

1. Atlantic salmon populations have declined in recent decades. Many of the threats to the species during its freshwater and coastal residency periods are known, and management approaches are available to mitigate them. The global scale of climate change and altered ocean ecosystems make these threats more difficult to address.
2. Managers need to be aware that promoting strong, healthy, and resilient wild populations migrating from rivers is the optimal approach currently to reduce the impacts of changing ecosystems and low marine survival. We argue that a fundamental strategy should be to ensure that the highest number of wild smolts in the best condition leave from rivers and coastal areas to the ocean. There is great scope for water quality, river regulation, migration barriers, and physical river habitat improvements.
3. Maintenance of genetic integrity and diversity of wild populations by eliminating interbreeding with escaped farmed salmon, eliminating poorly planned stocking, and reducing impacts that reduce population sizes to dangerously low levels will support the ability of Atlantic salmon to adapt to changing environments. Reducing the impacts from aquaculture and other human activities in coastal areas can greatly increase marine survival in affected areas.
4. As most of the threats to wild salmon are the result of human activities, a focus on human dimensions and improved communication, from scientific and management perspectives, needs to be increasingly emphasized. When political and social will are coupled with adequate resources, managers often have the tools to mitigate many of the threats to wild salmon.

     

水温对淡水温水性鱼类生命活动的影响

水温是影响鱼类生命活动的重要生态学因子。综述水温对淡水温水性鱼类的影响,为鱼类资源的增殖和水体生物多样性保护提供参考。从繁殖、摄食生长、代谢速率、临界游泳能力、免疫功能5方面的鱼类生命活动进行综述,其中,水温对鱼类的繁殖和生长影响最大,当水温适宜时,多数淡水温水性鱼类的各项生理活动都能正常进行;但当水温超过临界温度时会导致机体内代谢紊乱、活动能力降低、甚至造成鱼类死亡,最终引起鱼类种群结构和数量分布的显著变化。鱼类的临界游泳能力和高强度运动之后的重复运动能力也会受到水温的影响;鱼类免疫应答受水温影响较大,水温严重不适会导致免疫防御机制紊乱。水温只是影响鱼类生存的生态因子之一,但在航道建设、河流生态修复、鱼类资源评估以及水生态系统保护过程中均占据不容忽视的地位。在河流开发以及水文调节过程中,要最大限度降低其对水温生态因子的影响。     

A Survey of Water Quality Characteristics of Effluent from Hawaiian Aquaculture Facilities

Ten water quality parameters were measured in influent and effluent water at 11 aquaculture facilities in Hawaii. The data were grouped into four categories based on the types of organisms cultured: freshwater fish, freshwater prawn, marine fish, and marine shrimp. Within each category, concentrations of most parameters were lognormally distributed and spanned one to two orders of magnitude. Geometric mean concentrations of suspended materials, total nitrogen, total phosphorus, and pigments were highest in effluent from freshwater prawn ponds and lowest in marine fish pond effluent. Nitrate/Nitrite and total ammonia concentrations were higher in fish pond effluent than in crustacean pond effluent. Parameter concentrations were generally higher in effluent than in influent water, with freshwater fish and prawn ponds exhibiting the greatest increases in suspended materials and pigments. In contrast, nitrate/nitrite concentrations were lower in effluent than in influent waters. These data provide a basis for analyzing the environmental impacts of warm-water aquaculture effluent discharges.     

Particularities of early life stages in temperate freshwater fish species: comparisons with marine species and implications for aquaculture practices

Both egg and larvae are different between freshwater and marine fish species. Freshwater fish species have generally larger and fewer eggs than marine species. Most freshwater fish species have demersal eggs that develop stuck to various substrata, such as plants or gravels, while eggs of most marine fish species develop in the water column. These differences have consequences for both the evaluation of the quality and the incubation of eggs of freshwater fish species compared with marine species. The larvae of many freshwater fish species are larger and more developed at hatching than their marine counterparts: thus, larval feeding regimes could be different and cannibalism may emerge sooner in certain freshwater fish species. The main differences of egg and larvae between freshwater and marine species are highlighted and the possible implications for aquaculture practices are discussed.     

Effect of feed and feeding in the culture of salmonids on the marine aquatic environment: a synthesis for European aquaculture

While marine aquaculture has grown rapidly, so have concerns regarding the environmental impacts caused by the industry. In particular, increasing discharges of solid and dissolved fish excretions, nutrients and therapeutic chemicals have coincided with greater public awareness of the possibility of environmental damage. This has stimulated a number of criticisms, drawn from a wide spectrum of interests, ranging from the use of natural fish stocks to produce fish meal for aqua feeds to the effects of enhanced nutrient input on the coastal marine environment. The present study reviews available information on the environmental effects of feeding practices in salmonid aquaculture in Europe. Accumulation of waste food and fish faecal material results in changes in the sediment under fish cages, characterized by a low redox potential, high content of organic material and accumulation of nitrogenous and phosphorous compounds. Although significant environmental impacts have been reported in the literature at distances of up to 100 m from the cages, in general such impacts are reported to be localized to within 20–50 m around the cages. For farmed salmon and trout, mass balance models have been developed for nitrogen and phosphorus, indicating that 50% of the nitrogen and 28% of the phosphorus supplied with the food is wasted in dissolved form. The maximum nutrient release can be estimated from the hydrographic conditions in the immediate vicinity of the farm, such as water volume, tidal water exchange and currents. At present production levels, improvements in the feeding efficiency and feed quality of aquafeeds could reduce waste and consequent environmental impacts.     

Do Eurasian minnows (Phoxinus phoxinus L.) inhabiting brackish water enter fresh water to reproduce: Evidence from a study on otolith microchemistry

Dynamics of coastal fish assemblages in the Baltic Sea are still rather poorly understood. In particular, little information is available on migrations and movements of the small‐bodied littoral fish species like Eurasian minnow (Phoxinus phoxinus L.). Minnow is considered typically as a river and lake species, but it also inhabits brackish coastal waters of the Baltic Sea. In this study, we investigated movement patterns of brackish water inhabiting minnows using otolith microchemistry. Fish were collected from four different sites (from two bays and two stream mouths) around Saaremaa Island. The results indicated that at least three distinct migration patterns exist: (i) seawater residency, (ii) fast springtime migrations to fresh water or to bays with lower salinities (areas near stream mouths) and (iii) prolonged migrations to fresh water (some cases overwintering in streams). Migration patterns listed above were not evenly distributed among sites, and some individuals did not migrate to fresh water in every year. None of the analysed fish were freshwater residents. Additionally, potentially ontogenetic effects on Mn and Sr concentrations were observed in the otolith core regions, which may have important implications for the interpretation of otolith chemistry data. The overall findings of this study demonstrate that much more complex migration patterns exists in brackish water inhabiting minnow populations than previously thought and at least some individuals do enter freshwater to reproduce.     

春季和夏季杭州湾北部海域鱼类种群结构分析

为了解杭州湾北部海域鱼类种群组成及结构特点,利用相对重要性指数(IRI)、Cluster聚类和多元统计等方法对该海域鱼类种群结构进行分析。结果显示,春、夏季杭州湾北部海域共出现鱼类22种,隶属8目、12科、19属,鲈形目占比最高,为50.0%,其次为鲽形目和鲱形目,所占比例各为13.6%,生态类型以海洋性鱼类为主。调查共发现6种鱼类优势种,春季优势种为棘头梅童鱼(Collichthys lucidus)、鮸(Miichthys miiuy)和凤鲚(Coilia mystus),夏季优势种为棘头梅童鱼、白姑鱼(Pennahia argentata)、龙头鱼(Harpodon nehereus)、鮸和焦氏舌鰨(Cynoglossus joyneri)。Cluster聚类和非度量多维标度显示,杭州湾北部海域鱼类种群可分为春季组(Ⅰ组)和夏季组(Ⅱ组),春季组由5月站点组成,夏季组由8月站点组成,组间差异系数达到84.17%。ANOSIM分析表明,春季组和夏季组种群结构差异极显著(R=0.554,P0.01);BIOENV分析表明,春、夏季杭州湾北部鱼类种群结构与温度的相关性最高,相关系数为0.404。研究表明,杭州湾海域仍然是棘头梅童鱼、凤鲚等经济鱼类的产卵场和索饵场,鱼类种群结构的季节变化明显,棘头梅童鱼的生态洄游习性可能是造成种群结构变化的主要原因。     

Future prospects and their implications for research on the ecology of freshwater fish

Abstract– Projected world population increases imply demand for an increase of 60 million tonnes on the present world fish production of 100 million tonnes. Capture fisheries are unlikely to yield more because many stocks are already overexploited, there are few remaining unexploited and management shows few signs of redressing problems. Aquaculture is a possible source of the required production, given maintenance of current rates of increase. If this potential is to be realized, the importance of maintaining the quality of freshwater, brackish and coastal marine environments can scarcely be overstated. In a world of rapid change, there is an urgent need for research at all levels of biological and social organization that relate to the ecology of freshwater fish. At the organismic level, genetics, migratory behaviour and physiological ecology will be emphasized. Population genetics research is needed to enlighten controversies concerning the impact of cultural practices and the effects of harvesting natural populations. Greater attention will be given to interactions between species, including fish and their parasites, and the dynamics of multispecies interactions in pond culture and in capture fisheries. Issues of multiple uses of water resources will force research on freshwater fish ecology into broader contexts. The march of discovery in all branches of science will have major implications for freshwater fisheries research. The next few decades will be demanding of the creative energies of young researchers.     

Fish community responses to stream flow alterations and habitat modifications by small hydropower projects in the Western Ghats biodiversity hotspot,India

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Mountains‐to‐the‐sea conservation: An island perspective

1. Island nations such as New Zealand provide valuable insights into conservation challenges posed by strongly connected and recently developed or exploited freshwater and marine ecosystems.
2. The narrow land mass, high rainfall, and steep terrain of New Zealand, like many other island nations, mean that land‐based stressors are rapidly transferred to freshwater habitats and propagated downstream to coastal environments via short, fast‐flowing river systems.
3. Freshwater and marine environments are linked through faunal life histories; for example, diadromous fishes, many of which are considered threatened or at risk of extinction, and require cross‐ecosystem conservation to ensure survival of critical life stages and persistence of source populations.
4. Recent invasions of marine and freshwater environments by non‐indigenous species reveal rapid impacts on a naïve biota and highlight conservation conundrums caused by management aimed at enhancing native biodiversity by improving habitat connectivity.
5. Understanding and managing interconnected freshwater and marine ecosystems is a key concept for local indigenous communities, and highlights socio‐cultural connectivity and sustainable local harvesting of traditional resources as key elements of contemporary marine and freshwater conservation planning in New Zealand.

     

Leech (Myzobdella lugubris) infestations in largemouth bass (Micropterus salmoides) in Back Bay,Virginia, USA

Back Bay is an oligohaline, coastal bay in southeast Virginia, USA. Since 2004, leeches have been observed in the oral cavities of largemouth bass (Micropterus salmoides) in this body of water. Leeches (Myzobdella lugubris) have previously been documented in the oral cavities of largemouth bass in the Currituck Sound, which is confluent with Back Bay on its southern border. Supplemental stocking of largemouth bass in Back Bay since 2009 has resulted in an increasing population; however, concern exists that leech infestation may be negatively affecting health of larger fish, which are still less abundant than expected. Despite the wide distribution of this leech, there is little available literature regarding its health impacts on hosts. In this study, we examine potential impacts of oral leech infestations on stress markers and haematological parameters of largemouth bass in Back Bay. No significant changes in plasma glucose or cortisol were observed between leech‐infested and uninfested fish, and haematological parameters were not significantly different between the groups. Further, there was no evidence of systemic infections associated with leech infestation.     

Using flow guilds of freshwater fish in an adaptive management framework to simplify environmental flow delivery for semi‐arid riverine systems

Freshwater rivers have been substantially altered by development and flow regulation. Altered hydrological regimes have affected a range of biota, but impacts are often most obvious on freshwater fish. Flow largely influences the range of physical habitat available to fish at various life history stages. Biological rhythms are therefore often linked to flow and optimized so that opportunities for spawning, growth and dispersal are synchronized. Assuming that flow therefore becomes the main factor which structures freshwater fish communities, the use of species specific biological information should be able to inform adaptive flow delivery strategies from the river reach to catchment scale. A test of this assertion was performed as a case study of native fish within the Edward‐Wakool River system (New South Wales, Australia). Fish within the system were assigned to one of four groups based on biological similarity. Aspects of reproductive and movement ecology were then reviewed to generate optimal flow release strategies for each group. Life expectancy and hydrological constraints were then investigated and used to develop a possible 10‐year flow delivery program that could generate ecological outcomes within a strategic adaptive management framework that considered potential impacts on third parties. The approach could be used to develop flow characteristics to benefit biota in any watercourse provided enough data are available to link potential outcomes with flow delivery.     

Mapping China's freshwater fishes: diversity and biogeography

Freshwater fishes worldwide face an array of threats from dam construction, river fragmentation, pollution, over‐exploitation and interactions with introduced species. Such impacts are especially prevalent in densely populated countries undergoing rapid development, and their effects are felt most strongly where regional fish diversity is high. We reviewed studies of the distribution of freshwater fish species throughout China to map a biogeographical pattern and ascertain the environmental factors contributing to this distribution. We then linked this information to identify geographic areas to be recommended as the focus of conservation efforts. A total of 920 species in 302 genera, 54 families and 21 orders were recorded. Among the recorded species, 73% were Cypriniformes and 12% were Siluriformes. Cyprinidae was the most dominant family with 473 species, followed by Balitoridae with 157 species. The administrative division of the biogeography of China's freshwater fishes consisted of nine regions, including the Qinghai‐Tibetan Plateau Region, Oriental Region, Northwest Region, South Region, Loess Plateau Region, Heilongjiang Region, Upper Yangtze Region, 3H Plain Region and Middle‐Lower Yangtze Plain Region. The river system was the primary factor in determining China's freshwater fish biogeography. Under stepwise regression analysis, river discharge was found to be the most influential factor in determining richness, followed by population size and net primary productivity. The higher level of fish endemicity and sensitivity to environmental change led to the identification of Southwest China and the higher areas of Qinghai‐Tibetan Plateau as the primary areas to be considered for fish conservation and potential natural reserves.     

Alien species in aquatic environments: a selective comparison of coastal and inland waters in tropical and temperate latitudes

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Fish conservation in freshwater and marine realms: status,threats and management

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气候变化对长江口鱼类资源密度分布的重塑作用

本研究以2012-2013年长江口鱼类资源密度分布为基础,通过动态生物气候分室模型(DBEM)预估了不同气候变化情景下(IPCC,RCP2.6、RCP6.0和RCP8.5)长江口鱼类资源密度增量分布的变化.在RCP2.6、RCP6.0和RCP8.5这3种气候变化情景下,鱼类资源密度增量、底层鱼类资源密度增量随着时间推移均呈递增趋势,且递增程度和增量重心分布范围随着温室气体排放的增加而扩大(RCP8.5＞RCP6.0＞RCP2.6).鱼类资源密度增量重心主要分布在长江口崇明岛沿岸水域,长江口外侧水域资源密度增量相对较低,并且资源密度增量重心有向南迁移的趋势.     

鱼类卵子发育与卵泡闭锁的研究进展

鱼类种群繁衍离不开优质卵子的产出。卵子质量问题限制了许多海洋和淡水鱼类养殖业的发展。卵子质量主要受卵黄形成与卵母细胞发育的影响。亲本营养、管理以及其他内源或外源因素可能会影响卵黄组成与卵泡发育。与哺乳动物相比, 鱼类卵母细胞发育与调控机制的研究尚不清晰。本文分析了鱼类卵子发育特点, 探讨了亲本来源、育龄、环境因子以及营养等因素对鱼类卵子发生、发育与受精后仔鱼成活率的影响及其生理适应策略; 又从基因、miRNA 与蛋白表达等分子层面阐述了影响卵母细胞发育的分子调控机制; 解析了闭锁与过熟是卵泡发育的重要现象。本文在总结已有卵母细胞发育研究进展的基础上, 提出了闭锁卵泡的形成与调控可能的影响因素, 以期为深入理解卵泡闭锁在鱼类繁育生物学中的作用与其调控机制的研究提供理论参考。     

Environmental influences on life history strategies in partially anadromous brown trout (Salmo trutta,Salmonidae)

This paper reviews the life history of brown trout and factors influencing decisions to migrate. Decisions that maximize fitness appear dependent on size at age. In partly anadromous populations, individuals that attain maturity at the parr stage typically become freshwater resident. For individual fish, the life history is not genetically fixed and can be modified by the previous growth history and energetic state in early life. This phenotypic plasticity may be influenced by epigenetic modifications of the genome. Thus, factors influencing survival and growth determine life‐history decisions. These are intra‐ and interspecific competition, feeding and shelter opportunities in freshwater and salt water, temperature in alternative habitats and flow conditions in running water. Male trout exhibit alternative mating strategies and can spawn as a subordinate sneaker or a dominant competitor. Females do not exhibit alternative mating behaviour. The relationship between growth, size and reproductive success differs between sexes in that females exhibit a higher tendency to migrate than males. Southern populations are sensitive to global warming. In addition, fisheries, aquaculture with increased spreading of salmon lice, introduction of new species, weirs and river regulation, poor water quality and coastal developments all threaten trout populations. The paper summarizes life‐history data from six populations across Europe and ends by presenting new research questions and directions for future research.     

Using fatty acid markers to distinguish between effects of salmon (Salmo salar) and halibut (Hippoglossus hippoglossus) farming on mackerel (Scomber scombrus) and whiting (Merlangius merlangus)

Presence of coastal aquaculture activities in marine landscapes is growing with impacts on the wild fish that share these habitats. However, it is difficult to disentangle subsequent ecological interactions between these activities and marine fish communities. We evaluated the impact of both salmon and halibut farms on mackerel (Scomber scombrus) and whiting (Merlangius merlangus) sampled near sea cages using condition indices and fatty acid (FA) biomarkers. Results of the stomach content analysis indicated that mackerel and whiting consumed waste feed which was also reflected in their modified FA profiles. Both mackerel and whiting had elevated levels of FAs that are of vegetable oils origin. The use of vegetable oils as replacement for marine oils is a lot more common in salmon farming than halibut farming. Additionally, the overall effects of the two fish farms were more pronounced in whiting than in mackerel sampled near the sea cages. By allowing discrimination between sources of trophic interactions, this method could lead to more informed decisions in managing different farming activities.