Water resource management – the water utilities view

Abstract The potential effects of abstraction for water supply on salmonid populations in England and Wales are reviewed. The duties of water resource planning and the contribution of the water industry investment in river basin management planning are discussed. Given the possible effects of climate change on public water supply and demand, and the uncertainty of hydroecological relationships, key principles to ensure long‐term investment by water utility companies to meet European Union Water Framework Directive standards achieve the best benefit for salmonids are recommended.     

The role of aquaculture in the sustainable development of irrigated farming systems in Punjab, Pakistan

Natural resource managers in Pakistan today preside over a massive investment in water distribution infrastructure. An historical bias towards large-scale irrigation systems and a focus on water use for arable crop production appears to have contributed to an imbalance in food production in the region. This has resulted in the diminished supply and elevated price of fish and meat products, compounded by the disruption of natural fisheries. The situation is inconsistent with the regions food security needs and an important potential role exists for increased aquaculture development. Physically and organizationally, the integration of various fish production approaches into existing land and water use practices would also appear to be fundamentally feasible. There would appear to be strong economic justification for diversified water use involving fish production, especially small and medium-scale carp production in ponds, using ground water. More broadly, within the context of the limited potential for further expansion of water resources, integrated aquaculture could contribute a vital productive element to various components of the water distribution arid irrigated farming systems in the Punjab. These include: supply canals, provided diverse institutional and engineering objectives can be accommodated; groundwater (including potential application of saline groundwater); the farm sub-system, especially integrated rice and fish production options in conjunction with alternative pest control strategies such as Integrated Pest Management; and irrigation drainage systems, where water quality permits. Therefore urgent broad research objectives should include the definition, investigation and development of a series of distinct economic and environmentally sustainable approaches to integrated animal protein production from aquatic resources, presently managed principally for agricultural production. Approaches should involve both the replacement of lost fishery potential resulting from large-scale irrigation development and flood control management, and the development of net gains in aquatic output, and should focus particularly on efforts to promote recycling of agricultural residues, reduced pesticide use and efforts to make better use of scarce water resources through the integrated aquaculture production across a broad range of water resources. An increasing number of countries are approaching full development of their surface water resources, and like Pakistan many face the development of new management approaches to increase diversity and improve productivity in relation to water use. The lack of research in support of the development of integrated aquaculture, which lags many years behind comparable agricultural research, may be constraining the breadth of choice available to natural resource managers to meet their food security needs.     

Effects of hot dry summers on the loss of Atlantic salmon, Salmo salar, from estuaries in South West England

Salmon, Salmo salar L., were radio tagged in four estuaries in South West England. At medium to high summer flows, most salmon entering the river did so within 10 days of tagging. Lower flows were associated with an increased tendency for fish to remain in tidal water for a protracted period, and for those delayed fish to fail to enter the river. The delay was correlated with low freshwater flow, but it was concluded that high water temperature, and in some situations low dissolved oxygen, were likely to be the major influences. The causes of failure to enter the river by the delayed fish include lethally low levels of oxygen in some situations, but a major factor may be missed physiological opportunity. Implications in terms of water resource management, fisheries management and climate change are discussed.     

Economic evaluation of inland fisheries in England and Wales

Recreational inland fisheries are recognized to have considerable socio-economic benefits, not only for individuals participating directly but also for others in both local and wider communities. In England and Wales the Environment Agency (EA) has a duty to maintain, improve and develop inland fisheries. At present, there are no recent economic evaluations of the whole range of UK inland fisheries for the EA to refer to when confronted with resource issues. There is a particular need to explore the benefits of fisheries to the wider community, in order to secure more resources for management and protection of fisheries. Preliminary results from a multi-modular project to study the economic values associated with recreational fisheries in England and Wales are presented. Topics examined included recreational anglers' consumer surplus, general public non-use values of fisheries, social benefits of recreational fishing and impacts of fisheries on local communities.     

Evaluating effects of water withdrawals and impoundments on fish assemblages in southern New England streams,USA

Abstract Balancing aquatic conservation and water supply is becoming a major global issue for urban landscapes. The purpose of this study was to evaluate the ecological effects of stream‐flow alterations via water withdrawals and impoundments on fish assemblage structure. Electric fishing data were collected at 33 wadeable streams in Connecticut, located in the Southern New England region of USA. Fish sampling was conducted directly downstream of water withdrawals for municipal and agricultural water supply, and study sites differed in potential water withdrawal rates and the presence of impoundments. Regression analysis showed that water withdrawal rate was more important than other natural and anthropogenic factors (e.g. landcover and stream size) in explaining several fish assemblage metrics. Stream sites with high withdrawal rates were generally characterised by lower proportions of fluvial dependent fishes (fish which need flowing water to complete a portion of their life history) and benthic invertivores (fish which feed on bottom‐dwelling stream insects in riffle habitat), and had a greater percent composition of macrohabitat generalists, particularly members of the family Centrarchidae. Some assemblage metrics responded linearly with increasing magnitude of water withdrawals, but others were non‐linear. Results are consistent with ecological theory that alteration of the natural flow regime will impact stream biota.     

胶州湾及其邻近海域鱼类群落结构及与环境因子的关系

 为了进一步研究胶州湾及其邻近水域鱼类群落结构及与环境因子的关系, 本文根据2011年冬季(2月)、春季(5月)、夏季(8月)和秋季(11月)在胶州湾及其邻近海域进行的渔业资源和环境调查数据, 应用相对重要性指数、生态多样性指数和多元分析方法等研究了胶州湾鱼类群落结构及其季节变化, 并分析了胶州湾鱼类群落结构与主要环境因子的关系。结果表明: 本次调查共捕获鱼类57种, 隶属于2纲10目31科46属, 种类组成以暖温性和暖水性鱼类为主。主要优势种有方氏云鳚(Pholis fangi)和六丝钝尾虾虎鱼(Amblychaeturichthys hexanema)等。胶州湾鱼类群落物种丰富度指数D的季节变化范围为1.02~1.65, 多样性指数H’变化范围为1.36~1.73, 均匀度指数J′变化范围为0.61~0.76。方差分析表明, 丰富度指数的季节变化显著, 而均匀度指数J′和多样性指数H′无显著性季节变化。单因子相似性(ANOSIM)分析表明, 胶州湾鱼类群落结构和种类组成存在明显的季节更替现象。相似性百分比分析(SIMPER)表明, 方氏云鳚、六丝钝尾虾虎鱼、细纹狮子鱼、斑、赤鼻棱鳀和皮氏叫姑鱼等是造成群落结构季节变化的主要分歧种。典范对应分析表明, 影响胶州湾及其邻近海域鱼类群落结构的主要环境因子为水温、盐度和pH, 其次是底质类型, 条件效应分别为0.310、0.084、0.176和0.256。本研究旨在通过分析胶州湾鱼类群落结构和多样性特征及其与环境因子的关系, 为胶州湾渔业资源的保护和可持续利用提供科学依据。

     

Projecting future fish supplies using stock dynamics and demand

Supply–demand models, which are commonly used in food policy analysis, have been recently applied to generate projections of future fish supplies. However, these models routinely ignore stock dynamics; hence, threats to sustainability due to declining fish stocks are addressed, at best, by exogenous changes in resource productivity. Such a device is ad hoc, as it is unclear whether the assumed shifts are consistent with known patterns of population adjustment. On the other hand, bioeconomic models incorporate stock dynamics, but typically omit price adjustment arising from the interaction of demand and supply. An applied supply–demand model with stock dynamics combines the strengths of both approaches. However, data problems constrain the formulation of such a model. Instead, this study presents a prototype bioeconomic supply–demand model. Simulations show trends in fish supply that fail to appear in either supply–demand or bioeconomic models. Secular demand growth causes initial production growth, followed by stagnation, and then persistent decline. Moreover, under constant pressure from rising demand, capture production fails to recover completely from adverse population shock (such as may be induced by climate change). The prototype model highlights the potential usefulness of an applied bioeconomic supply–demand model for food policy and fisheries management, and provides a template for future work.     

Koi herpesvirus: distribution and prospects for control in England and Wales

Koi herpesvirus (KHV) causes a highly virulent disease affecting carp, Cyprinus carpio L., and poses a serious socio‐economic threat to the UK carp industry. This study aimed to determine the geographic distribution and prevalence of KHV exposed fish in England and Wales through ELISA antibody testing. Only three of the 82 farms sampled produced positive results, suggesting fish farms provide a relatively safe source of fish. Of the 71 ‘high‐risk’ fisheries tested, 26 were positive. All eight geographic areas within England and Wales studied had at least one KHV positive site. Twelve consignments of imported koi carp from seven S.E. Asian countries were tested for KHV antibody. Six consignments from six different countries were positive. Although a high proportion of consignments were positive, the results indicate that lower risk stocks of fish exist that could be sourced by the ornamental carp sector. The study provides evidence that KHV is widespread and prevalent in ‘high‐risk’ fisheries. There are, however, prospects for controlling KHV as English and Welsh farms appear to be relatively free of the virus, and in most cases fish are not moved from fisheries to other waters.     

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。     

Potential impact of groundwater augmentation of river flows on fisheries: a case study from the River Ouse, Yorkshire, UK

Many lowland rivers in the UK are under increasing pressure from abstraction of water for potable supply or irrigation. Many schemes, both existing and proposed, attempt to mitigate the loss of flow by augmentation from upstream reservoirs or pumping of groundwater into adjacent rivers. The impact of flow regulation by reservoirs is well documented, but little attention has focused on the effect of groundwater augmentation on the biota, particularly fisheries, in the receiving river. The present paper examines the potential effects of pumping groundwater into minor tributaries of the Yorkshire Ouse in England on the cyprinid fisheries downstream of the discharge points and in the main river channel. Concerns were raised with respect to poor water quality and reduced water temperature. In particular, it was predicted that small reductions in river water temperature brought about by discharge of cold (≤ 10 °C) groundwater could have serious detrimental effects on cyprinid fish recruitment and juvenile growth in the receiving river, leading to a decline in stocks.