Aquaculture and the environment: the supply of and demand for environmental goods and services by Asian aquaculture and the implications for sustainability

The present paper explores the relationships between aquaculture and the environment In Asia, focusing on the demands for environmental goods and services among different sectors. Aquaculture in the region accounts for 88% of global production by weight and 80% by value. Nevertheless, environmental problems are increasingly apparent and the higher the demands for environmental goods and services, the more negative the impacts. Against a background of rapid social, economic and political change, the paper considers how the sustainability of the industry is best assured. An integrated view of resource use, in which aquaculture is but one activity, is necessary for sustainable development. The roles of planning, education, research and environmental management schemes are discussed.     

European estuaries and lagoons: A personal overview of problems and possibilities for conservation and management

1. European estuaries and lagoons fall into three categories in respect of their conservation status and potential for ecological management. (i) Small lagoons, although greatly reduced by natural and man-made changes to the coastal environment, are relatively easily recreated behind longshore shingle barriers, but natural colonization of such habitats may have ceased and successful artificial introduction of species or whole assemblages is hampered by lack of knowledge of the processes structuring natural lagoonal communities. (ii) Small estuaries require very little conservation management, only control of further human exploitation especially in respect of the siting of marinas and other recreational usage. (iii) Large estuaries are in many cases already altered beyond recognition, and such is their economic importance that it is unlikely that the pressures for further reclamation, impoundment, and development will be resisted. Nevertheless, it is may be possible to protect areas within each such estuarine system that could serve as staging posts for migratory birds. 2. Integrated action is needed to assess the status and importance of the remaining European estuarine and lagoonal habitats, and to conserve and manage them in the future, if they are to continue to provide any significant habitats for organisms into the 21st Century and beyond.     

海龟的主要疾病及防治措施

海龟是国家二级保护动物,对海龟的常见的疾病及病因并就起防治方法进行了简单的阐述,有利于我们更好地保护海龟,为进一步开展海龟其他方面的研究打下良好的基础.     

Probiotics in fish and shellfish culture: immunomodulatory and ecophysiological responses

Aquaculture is emerging as one of the most viable and promising enterprises for keeping pace with the surging need for animal protein, providing nutritional and food security to humans, particularly those residing in regions where livestock is relatively scarce. With every step toward intensification of aquaculture practices, there is an increase in the stress level in the animal as well as the environment. Hence, disease outbreak is being increasingly recognized as one of the most important constraints to aquaculture production in many countries, including India. Conventionally, the disease control in aquaculture has relied on the use of chemical compounds and antibiotics. The development of non-antibiotic and environmentally friendly agents is one of the key factors for health management in aquaculture. Consequently, with the emerging need for environmentally friendly aquaculture, the use of alternatives to antibiotic growth promoters in fish nutrition is now widely accepted. In recent years, probiotics have taken center stage and are being used as an unconventional approach that has numerous beneficial effects in fish and shellfish culture: improved activity of gastrointestinal microbiota and enhanced immune status, disease resistance, survival, feed utilization and growth performance. As natural products, probiotics have much potential to increase the efficiency and sustainability of aquaculture production. Therefore, comprehensive research to fully characterize the intestinal microbiota of prominent fish species, mechanisms of action of probiotics and their effects on the intestinal ecosystem, immunity, fish health and performance is reasonable. This review highlights the classifications and applications of probiotics in aquaculture. The review also summarizes the advancement and research highlights of the probiotic status and mode of action, which are of great significance from an ecofriendly, sustainable, intensive aquaculture point of view.     

Fish genetics and conservation research in India: status and perspectives

Recent years have witnessed a rise in sensitivity towards protection of natural genetic resources and the environment at the international level. This is evident from the implementation of the convention on biodiversity (CBD). To conserve and optimize utilization of its bioresources, India enacted the Biological Diversity Act 2002. The conservation and management of aquatic resources is important for sustainable utilization of fisheries potential for the economic advancement of farmers and fishery workers, today as well as for posterity. As the biotechnological and genomic revolutions are ready to take off, the sovereign rights of native inhabitants to intellectual property rights (IPR) related to aquatic genetic resources and associated traditional knowledge are also integral components of management strategies for genetic resources.     

孔雀石绿的污染治理及样品中残留物的分离检测方法

孔雀石绿是一种三苯甲烷类化合物,作为一种重要的化工原料、碱性染料、杀真菌剂、生物染色剂得到了广泛的应用.由于其毒性和可致癌性,已经被禁止用于水产品生产和运输过程中.综述了孔雀石绿污染物的治理和样品中其残留物的分离检测方法.     

氨氮和亚硝酸氮快速准确测定方法研究

本研究提出了用液体标准色阶快速准确测定氨氮和亚硝酸氮的比色方法。研究的液体标准色阶的稳定时间在一年以上，氨氮和亚硝酸氮的测定误差分别为0．2mg／L和0．02mg／L。用本方法对名种类型的水样进行测定，结果表明，本方法与传统的分光光度法测定结果一致，适于海淡水养殖单位的现场使用。     

Aquaculture Net Drag Force and Added Mass

The hydrodynamic loads on plane net samples of differing mesh geometry are measured in steady and oscillating flows. The steady loads on plane nets are also numerically simulated. The net is modeled as an inter-connected system of lumped masses and springs. The loads are computed for each twine segment and applied to the lumped masses at the segment ends. The equations of motion are formulated for the coupled dynamics of the masses and solved numerically. Drag data from the experiments is compared with analytical and numerical models and existing empirical formulae. Results for steady flows indicate that drag coefficients for nets and cylinders, as a function of the Reynolds number, have identical trends with consistent offsets. It is concluded that the drag coefficient for nets is equivalent to the drag coefficient for cylinders (and spheres for knotted nets) modified by a function of net solidity. For unsteady flows, the drag and added mass are extracted from the total wave force by applying a vector approach. It is shown that drag and added mass coefficients are not well quantified by conventional non-dimensional parameters (i.e. Keulegan–Carpenter and Reynolds numbers). The unsteady drag coefficient is presented as a function of wave particle velocity, wave period and net porosity. It is proposed that the added mass coefficient be expressed by an assumption of an effective thickness—conceptually the width of water affected by the net, which is a function of wave frequency and net solidity.     

Reproductive ecology and scientific inference of steepness: a fundamental metric of population dynamics and strategic fisheries management

The relationship between the biomass of reproductively mature individuals (spawning stock) and the resulting offspring added to the population (recruitment), the stock–recruitment relationship, is a fundamental and challenging problem in all of population biology. The steepness of this relationship is commonly defined as the fraction of recruitment from an unfished population obtained when the spawning stock biomass is 20% of its unfished level. Since its introduction about 20 years ago, steepness has become widely used in fishery management, where it is usually treated as a statistical quantity. Here, we investigate the reproductive ecology of steepness, using both unstructured and age-structured models. We show that if one has sufficient information to construct a density-independent population model (maximum per capita productivity and natural mortality for the unstructured case or maximum per capita productivity, natural mortality and schedules of size and maturity at age for the structured model) then one can construct a point estimate for steepness. Thus, steepness cannot be chosen arbitrarily. If one assumes that the survival of recruited individuals fluctuates within populations, it is possible, by considering the early life history, to construct a prior distribution for steepness from this same demographic information. We develop the ideas for both compensatory (Beverton–Holt) and over-compensatory (Ricker) stock–recruitment relationships. We illustrate our ideas with an example concerning bluefin tuna ( Thunnus thynnus/orientalis , Scombridae). We show that assuming that steepness is unity when recruitment is considered to be environmentally driven is not biologically consistent, is inconsistent with a precautionary approach, and leads to the wrong scientific inference (which also applies for assigning steepness any other single value).     

Ecthyma of sheep and goats

Contagious pustular dermatitis (CPD, contagious ecthyma, Orf) is a highly contagious viral disease afflicting sheep and goats. The infectious agent is a parapoxvirus which is widespread and also contagious for humans (zoonosis). Recently the disease in sheep and goats is marked by increased incidence and severe cases which cause many losses especially among lambs in fattening farms. The immunity of once infected animals is based on cellular defense mechanisms which are very unstable. The most suitable method for the prevention of ecthyma is parenteral vaccination with attenuated live vaccines. Effective vaccination programmes should enclose the whole animal population at intervals of 6-8 months.     

我国渔业节能减排研究与发展建议

在实地采样调研和数据分析的基础上,得出我国每年海洋捕捞渔船的燃油消耗为637万t,其中拖网和刺网渔船分别占58.8%和22.2%,是渔船燃油消耗的主体;推算出每年渔船总燃油消耗为790万t,渔业生产领域总能源消耗为1 754万t标准煤,其中水产捕捞、养殖和加工所占的比重分别为66%、21%和13%,并以万元产值能耗为指标对渔业及其主要领域的能源利用水平进行比较分析。在对渔业节能减排总体水平进行全面分析的基础上,指出降低渔业能耗的主要领域是拖网渔船和刺网渔船,控制渔业排放的主要领域是池塘养殖和工厂化养殖;标准化渔船技术、玻璃钢渔船技术、循环水养殖技术等是推进渔业节能减排的主要技术支撑;参考国外渔业节能减排技术状况,提出发展目标和主要措施等方面的建议。     

Status, trends and management of sturgeon and paddlefish fisheries

The 27 extant species of sturgeons and paddlefishes (Order Acipenseriformes) represent a unique and relict lineage of fishes. Producers of coveted black caviar, sturgeons are one of the most valuable wildlife commodities on earth. The group is among the most endangered fishes with all species listed under Convention on International Trade in Endangered Species (CITES) Appendix I (two species) or II (25 species), only two species considered Lower Risk by IUCN, four of the nine US taxa and one Caspian species protected under the Endangered Species Act, and local extinctions recorded for 19 of 27 species. Despite their well‐publicized imperilled status, commercial pressure on 15 species persists. Here, after reviewing the biological characteristics of sturgeons and paddlefishes and their commercial use, an overview of global fisheries is presented. The synopsis demonstrates that, with few exceptions, sturgeon and paddlefish are imperilled across the globe and long‐term survival in the wild is in jeopardy. All major sturgeon fisheries have surpassed peak productivity levels, with 70% of major fisheries posting recent harvests <15% of historic peak catches and 35% of the fisheries examined crashing within 7–20 years of inception. Even in Caspian Sea fisheries, the most important globally, present catches are below 10% of historic peak landings. Improved domestic and international fisheries management and attention to habitat and species restoration is now needed. Although captive rearing offers promise for caviar alternatives and endangered species restoration, it must advance cautiously to avoid environmental harm. To ensure a continued supply of caviar and the survival of these unique fishes we offer recommendations for priority conservation action for the future.     

Characterisation of aquaponic producers and small-scale facilities in Spain and Latin America

Aquaponics is a sustainable food production system combining hydroponics and aquaculture. Although the domestic/small-scale aquaponic production has proliferated worldwide, there is scarce knowledge about how it is performed. The objective of this study was to determine the profile and motivations of aquaponic producers, the characteristics of the facilities and the performance of the production. The average aquaponic producer is a middle-aged man, with a certain level of studies and a moderate household income. The main motivations reported were the production of high-quality, healthy food, the concern for the environment and the autonomy gained. These motivations conditioned the purposes of the aquaponic facilities (mainly education, production of food for self-consumption and as a hobby), which, excepting small sales, did not have an economic motive. Due to their characteristics, aquaponic facilities are particularly adapted for urban agriculture (many of them were located on rooftops) and most of those studied were constructed recently. The nutrient film technique was the most used hydroponic subsystem, followed by media beds, where mostly a polyculture of leaf and fruit vegetables and aromatics are produced. Tilapia was the most common fish species used. In general, there is a lack of proper knowledge and expertise about these complex systems in order to efficiently operate them.

     

柠檬酸、Nisin-柠檬酸联合对三种常见水产病原菌的作用

选用嗜水气单胞菌、副溶血弧菌、荧光假单胞菌三种常见水产病原菌,用于测定柠檬酸的抑菌效果及最小抑菌浓度,并研究了柠檬酸抑菌作用的稳定性。三种菌均为革兰氏阴性菌。试验结果表明,柠檬酸对三种菌都有不同程度的抑菌作用,并得到最小抑菌浓度,依次是:0.0011g/mL,0.0008g/mL,0.00125g/mL;在最小浓度下抑菌作用可达6d之久,柠檬酸抑菌效果有一定的稳定性。将Nisin溶于0.00125g/mL,得到复合液的抑菌效果强于柠檬酸单独作用,且稳定性增强。     

Nutritional bioenergetics and estimation of waste production in non-salmonids

The general principles behind the bioenergetic approach for predicting growth, as well as for decreasing feed and nutrient losses, have been set forth for salmonids. Given the diversification of fish fanning activities around the world and the ever increasing concern for water quality management, it becomes essential to verify whether an approach developed for salmonids is applicable to other species. Given this general background, an attempt is made here to check the theoretical assumptions and technical considerations behind the bioenergetic principles developed for rainbow trout with other freshwater or marine species. From a conceptual point of view, recent literature data do indicate that as far as nitrogen or energy balance is concerned, the general scheme is as valid for marine species as it is for salmonids, even in quantitative terms. Given the methodological tools available today, it should not be difficult to reduce feed and nutrient losses and to estimate the potential environmental loadings using the same principles for non-salmonids.     

Induced maturation and spawning: opportunities and applications for research on oogenesis

Broodstock management requires the ability to detect and regulate oocyte growth, acquisition of maturational competence, maturation of oocytes, and onset of ovarian atresia. Our research on temperate basses (genus Morone) has supported development of these capabilities. These investigations have revealed that accumulation of neutral lipid droplets and deposition of vitellogenin-derived yolk proteins in growing oocytes are independent processes with different sensitivities to changing day length and water temperature. In these fishes, completion of oocyte growth is marked by disappearance of vitellogenin from ovarian biopsy samples. Competence of females for induced spawning is predicted by the ability of biopsied follicles to initiate oocyte meiosis in vitro in response to insulin-like growth factor I. Cytoplasmic maturation of the oocytes is triggered by the maturation-inducing steroid hormone and can be monitored by evaluating degradation of the yolk proteins. Onset of ovarian atresia is indicated by the appearance of edema in the granulosa cell layer of biopsied follicles, and can be delayed for months by holding gravid females at abnormally low temperature (`cold banking'). These novel findings hold strong promise for application to other farmed fishes.     

Wintering seaducks in Britian and Ireland: Populations,threats, conservation and research priorities

• 1. This paper provides a detailed review of the status and distribution of wintering seaducks (Scaup, Eider, Long-tailed Duck, Common Scoter, Velvet Scoter and Red-breasted Merganser) in Britain and Ireland. It is based on a literature review plus analysis of National Waterfowl Counts (NWC) and other data. A summary of current knowledge of wintering seaducks is provided together with information on threats to populations, conservation goals and research needs.
• 2. Each species is examined in turn, with the emphasis on aspects of the population, habitat use, current distribution, trends and history. Important areas for individual species are highlighted.
• 3. Overall, seaduck populations have changed considerably, those for Eider and Red-breasted Merganser having expanded greatly, whilst those for Scaup, Common and Velvet Scoter have declined during historical and/or recent times. The trend for Long-tailed Ducks is unclear. British population estimates are considered to be out of date and need to be revised. The premier areas for seaduck communities are highlighted, thus providing basic information for conservation action and future monitoring.
• 4. Seaduck populations are threatened in a number of ways and the main factors are discussed. Oil pollution and the actions of commercial fisheries are the most important current threats. Conservation goals are suggested. These include an urgent need to develop appropriate domestic legislation to facilitate the protection of seaduck populations. Such legislation is currently almost entirely lacking.
• 5. Some priorities for research, particularly for better population monitoring of seaducks in British and Irish waters, are provided. These include: alterations to the NWC scheme to allow the collation of opportunistic counts, made when the conditions are amenable for censusing seaducks; extension of the scheme into areas not currently surveyed (e.g. most parts of Ireland); and the establishment of intensive survey programmes to monitor seaducks in the key areas of Britain and Ireland. It is hoped that this paper will serve to stimulate interest and commitment from all who play a part in safeguarding our seaduck heritage.

     

Interactions and management for the future of marine aquaculture and capture fisheries

Aquaculture surpassed wild fisheries as the largest supplier of fish for human consumption in 2014 and is expected to supply the majority of seafood for future increases in demand. Marine and coastal aquaculture, collectively referred to as mariculture, currently represents just 36% of aquaculture production but is poised to expand in the decades ahead. One of the most commonly cited concerns regarding this likely expansion is ecological and socioeconomic interactions with wild‐capture fisheries. While attention has largely been drawn to high‐profile negative externalities from fed finfish and crustacean mariculture, not all marine‐based practices are equivalent. Empirical evidence for the different interactions between mariculture and wild fisheries is often sparse. While negative consequences can arise, positive synergies can also occur. By considering mariculture development in the context of fisheries interactions, we suggest that it is possible to minimize conflicts and maximize positive connections between the two sectors. We provide the first comprehensive synthesis of the interactions between mariculture and wild fisheries, characterizing the types of interactions, evaluating available empirical evidence and identifying where management (sector‐specific and cooperative) can play an important role. We highlight potential effects of mariculture on the efficiency, sustainability, and equity of seafood production and identify remaining knowledge gaps.     

真蛸及其繁育研究

真蛸(Octopus sinensis)俗称章鱼、红章,主要分布于温带、亚热带和热带海域,是我国南方重要经济物种,具有生长速度快、繁殖力强和经济价值高等特点.真蛸体质量日增长率可达13％,食物转化率15％～43％,80 g幼蛸经过3个月养殖可长至1 500 g,成熟母体产卵量6万～20万粒/只,适于规模化繁育和养殖,是...     

Review of recent carrying capacity models for bivalve culture and recommendations for research and management

Models and tools for assessing the carrying capacity of an area of interest for bivalve culture can be classified according to their level of complexity and scope. In this report, we discuss and outline four hierarchical categories of carrying capacity studies: physical, production, ecological, and social carrying capacity. The assessment of carrying capacity for progressively higher categories of models is based on a sound understanding of preceding categories. We discuss each in brief and the third in more detail as this is the level at which knowledge is the most lacking and for which science may make the most advances.(1) Physical carrying capacity may be assessed by a combination of hydrodynamic models and physical information, ideally presented and analysed within a Geographic Information System (GIS). (2) Most scientific effort to date has been directed towards modelling production carrying capacity and some of the resulting models have been used successfully to this end. Further development of these models should pay attention to (i) better modelling of feedback mechanisms between bivalve culture and the environment, (ii) a consideration of all steps in the culture process (seed collection, ongrowing, harvesting, and processing), and (iii) culture technique. (3) The modelling of ecological carrying capacity is still in its infancy. The shortcomings mentioned for models for production carrying capacity estimates are even greater for ecological carrying capacity models. GIS may be employed to consider interactions between culture activities and sensitive habitats. (4) It is recommended that social carrying capacity be evaluated only after the preceding levels have been completed so that an unbiased assessment is obtained. This however does not exclude direction from managers for scientists as to which factors (such as water clarity, specific habitats, etc.) should be evaluated. The use of expert systems to aid in management decisions is briefly discussed with a suggested application of a fuzzy expert system to this end.