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1.
Organic aquaculture has lagged behind the agriculture sector in terms of the quantities and diversity of certified organic products because of the absence of detailed accepted standards and criteria until recently. The main challenges for organic aquaculture are to improve the coordination between production and market and to achieve an appropriate framework to drive further development. Priorities for research include organic feeds and fish nutrition, consumers’ needs, food safety, environmental concerns and trade issues. In organically cultured fish, differences in feeds and nutrition compared to conventional systems are likely to result in differences in the quality of the flesh, and this is a significant factor in consumer choice. The review covers aspects of current use of eco‐certification, formulated feeds, feed composition, aquafeed technology, sustainable alternatives to common feed ingredients, nutritional physiology and general nutritional principles and product quality in the context of the organic aquaculture. There is a future for the development of organic aquaculture but its success depends on new knowledge and technical development to meet consumers’ growing interest. The industry has to utilize the research results and update and modify the criteria and standards and thus provide high‐quality products.  相似文献   

2.
Competition for fish oil from human nutritional supplements (nutraceuticals) is starting to threaten its supply for aquaculture feeds. World supply of fish oil is not increasing but is the main source of healthy omega-3 fats (n-3 LC-PUFA). Fish oil demand by nutraceuticals is a derived demand for such fats. Demand growth and insecure supply are causing price inflation of fish oil, helping to drive its substitution in aquaculture feeds by vegetable oils. This is reducing the content of n-3 LC-PUFA in aquaculture products, especially salmon, with potentially negative health implications. Given the scope for further substitution of fish oil, it is unlikely that future growth of global aquaculture will be constrained by reducing omega-3 content, although it will complicate consumer marketing of salmon. Nutraceuticals is paying more than aquaculture for fish oil based on omega-3 content, but novel sources of n-3 LC-PUFA will become available in the medium term.  相似文献   

3.
Aquaculture is a sector of economic relevance worldwide. Bacterial infections have been recognized as an important limitation to aquaculture production and trade. Microbial infection in aquaculture derived products has been prevented by antibiotic administration with limited success. Recently, drug-resistant bacteria have become a global problem, urging for the prompt development of alternative control strategies in order to improve food quality and safety. The alternative approach of using lytic phages or their products, as bioagents for the treatment or prophylaxis of bacterial infectious diseases, has gained interest. This review intends to emphasize the need of further research in the field of the application of phage therapy in aquaculture and highlights the use of phages in invertebrates as an antimicrobial strategy pointing critical aspects from the economic, environmental and public health perspectives.  相似文献   

4.
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.  相似文献   

5.
Aquaculture has evolved as the fastest growing food-producing sector and developed as an important component in food security. To keep a sustainable growth pattern, health management strategies must go beyond antibiotics and chemotherapeutics, which create resistant bacteria and immunosuppression in the host. Besides development of drug resistant bacteria and pathogens, the adverse effect of antibiotics is caused by their influence on the aquatic microflora, and the retention of harmful residues in aquatic animals. On the other hand, the microbes with their unique structure and cell wall components can trigger immunity, and thus exposure plays an important role in the evolution. Microbial intervention through an environmentally friendly approach is an alternative method of health management. India is endowed with a bounty of varied climatic conditions, microbial diversity and fish fauna and aquaculture systems offering challenges in biological and environmental pursuits. Producing about 4.4% of world’s fish and ranking third in global fish production, India trades about 2.4% in global fish market with the annual export earning being over $1311 million. Use of microbes for beneficial purposes is increasingly recognized as a valuable input for sustainable and responsible aquaculture. Microbial intervention in aquaculture can be broadly water/environment based through bioaugmentation, biostimulation, biocontrol measures, or (to generate) host response through probiotics, immunostimulants, and vaccines. Also, application of molecular methods such as polymerase chain reaction (PCR) and nucleic acid techniques are making increasing inroads into aquatic microbiological research in India. This paper elucidates all these aspects of microbial intervention in aquaculture, high-lighting Indian research and accomplishments.  相似文献   

6.
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.  相似文献   

7.
在水产养殖中,抗生素是用来治疗细菌性疾病最有用的药物。但近些年的研究发现,过度使用抗生素,反而诱导产生了一系列带有抗性基因的致病菌,严重制约了水产养殖业的发展。本文以近15年来国内外相关研究的文献为依据,概括介绍了抗生素抗性基因(ARGs)的产生及其传播途径、ARGs污染的危害性、国内外ARGs污染研究现状及加强ARGs污染研究的必要性等4个方面的研究进展,围绕抗性基因的检测、ARGs的传播、扩散及作用机制和控制、消除ARGs的方法等方面进行了后续研究重点的展望,以期为我国水产养殖行业的可持续发展提供依据。  相似文献   

8.
Fisheries and aquaculture production, imports, exports and equitability of distribution determine the supply of aquatic food to people. Aquatic food security is achieved when a food supply is sufficient, safe, sustainable, shockproof and sound: sufficient, to meet needs and preferences of people; safe, to provide nutritional benefit while posing minimal health risks; sustainable, to provide food now and for future generations; shock‐proof, to provide resilience to shocks in production systems and supply chains; and sound, to meet legal and ethical standards for welfare of animals, people and environment. Here, we present an integrated assessment of these elements of the aquatic food system in the United Kingdom, a system linked to dynamic global networks of producers, processors and markets. Our assessment addresses sufficiency of supply from aquaculture, fisheries and trade; safety of supply given biological, chemical and radiation hazards; social, economic and environmental sustainability of production systems and supply chains; system resilience to social, economic and environmental shocks; welfare of fish, people and environment; and the authenticity of food. Conventionally, these aspects of the food system are not assessed collectively, so information supporting our assessment is widely dispersed. Our assessment reveals trade‐offs and challenges in the food system that are easily overlooked in sectoral analyses of fisheries, aquaculture, health, medicine, human and fish welfare, safety and environment. We highlight potential benefits of an integrated, systematic and ongoing process to assess security of the aquatic food system and to predict impacts of social, economic and environmental change on food supply and demand.  相似文献   

9.
Aquaculture in Brazil has shown expressive development since the 1990s with growth rates superior to those of cattle and poultry. In order to achieve greater productivity, intensive fish cultivation systems are employed, which can cause greater susceptibility to diseases caused by viruses, bacteria, fungi, and parasites. The reduced availability of veterinary medications approved for use in aquaculture in Brazil has lead fish farmers to the indiscriminate use of several chemical substances with antimicrobial activity, such as the dye malachite green (MG). As a result of this use, residues of MG and its main biotransformation product, leucomalachite green (LMG), may be present in fish available for consumption. The presence of residues of these compounds represents a risk to human health due to their toxicity, as well as a potential impact on the environment, and could also raise barriers for commercialization in the country and for exportation. The objective of this review is to provide the context and evidence of the use of MG in aquaculture and of its toxicological and legislative aspects. A review of the analytical methods used to determine MG residues in fish, with emphasis on mass spectrometry, is also presented.  相似文献   

10.
Sustainability issues are becoming increasingly important in Western food consumption. This research aims at identifying ways to increase the market share of sustainable fish from aquaculture by analyzing consumer awareness and preferences for sustainable aquaculture products and by drawing conclusions on improving communication in the German market. An integrative research approach was used: it began with an inventory of sustainable seafood products on the German market, followed by qualitative and quantitative consumer research, and ending with a stakeholder workshop, which reflected on the research outcome with practitioners. Sustainability and country of origin proved to be of minor relevance to the vast majority of the consumers interviewed. Indeed, attributes such as freshness, taste, and price frequently ranked higher. Like most of the other consumers, the small consumer segment that is generally interested in sustainability issues of food also often lacks knowledge of fish farming and its products. Consequently, communication of sustainability in aquaculture is challenging, and the development of this market requires concerted actions along the whole value chain, with the retail sector as the main actor.  相似文献   

11.
Globally, one‐sixth of landings from marine capture fisheries are destined for the production of fishmeal and fish oil (FMFO), which are currently overwhelming utilized by fed aquaculture. Many different species are used globally for the production of FMFO, but little concern has been given to the divergent environmental and ecological impacts of FMFO products based on species, ecosystem and fishing gear used in their capture. We evaluated the variable environmental performance of FMFO products from a wide range of fisheries whose products are either primarily intended for reduction or whose by‐products are redirected to reduction. Assessed fisheries accounted for 44% of global reduction fishery landings in 2014. Analysis was conducted on the basis of two measures: the carbon footprint (i.e., greenhouse gas [GHG] emissions) and the marine footprint (i.e., primary production required [PPR]). We found large differences between the impacts of FMFO products across the 18 reduction fisheries examined. Cumulatively, we estimate that reduction fisheries emitted 4.6 million tonnes of CO2‐e GHGs in 2014, and appropriated over 4% of primary production in some ecosystems, demonstrating a non‐trivial impact. As demand for aquafeeds grow, the sustainable sourcing of raw material inputs will be of great importance. Results here suggest that the source of FMFO inputs can have dramatic effects on the environmental performance of fish feeds and fed aquaculture. We recommend further research on the environmental and ecological impacts of food production systems, and specifically to understand these results in relation to global production and sustainable boundaries.  相似文献   

12.
Strategies for further development of aquatic feeds   总被引：4，自引：1，他引：4  
ABSTRACT: To date, aquatic feeds have depended heavily on fishmeal and fish oil as their source of protein and lipid. However, the feed industry is encountering shortfalls in the availability of these ingredients because of a decline in the number of fish captured in the wild and the increased human demand for some of the species currently being used for fishmeal and oil production. Therefore, efforts are now being directed in different parts of the world to finding alternative quality ingredients, which ideally are less expensive and readily available for use in practical diets. The data accrued have shown that a large proportion of both fishmeal and fish oil can be replaced by other protein and lipid sources. However, it is emphasized that an optimal essential amino acid balance be maintained and that the n-3 highly unsaturated fatty acid requirement be satisfied when combining economical protein and lipid ingredients. Newly developed feeds should aim at being nutrient-dense in order to reduce the output of solid, P and N waste. This can be done through improving nutrient availability, optimizing the digestible protein to energy balance of the diet, and replacing dietary fishmeal with alternate ingredients. These diets should also be effective for maintaining good health and improving disease resistance in fish through enhancement of immune responses. A wholesome approach to culturing fish would be to use appropriate feeding standards that are aimed not only at improving economic returns but also at developing a lasting cohabitation of sustainable aquaculture and a cleaner environment. Furthermore, in the 2lst century aquaculture would still retain its place as a prominent source of food protein, signifying that fish feed research remains a forceful area in discovering better feeds for the industry.  相似文献   

13.
多效价载体疫苗免疫大菱鲆效果评价   总被引：2，自引：1，他引：1  
采用注射与浸泡2种方法,对构建的多效价载体疫苗MVAV6203A-1进行了免疫保护效果和血清效价的研究.结果显示,用多效价载体疫苗注射免疫大菱鲆(Scophthalmus maximus),可同时获得对鳗弧菌(Vibrio anguillarum)和嗜水气单胞菌(Aeromonas hydrophila)的免疫保护效果,免疫相对保护率分别为80.6％和77.0％;用ELISA方法测定血清效价的结果显示,免疫MVAV6203A-1后大菱鲆血清效价最高达到2 048,均值为891,明显高于对照组的97;用多效价载体疫苗浸泡免疫大菱鲆后,对鳗弧菌与嗜水气单胞菌的免疫相对保护率分别为62.2％和11.7％.血清效价分析显示,实验组与对照组的均值均为64.上述结果表明,所构建的疫苗MVAV6203A-1可有效提高大菱鲆对鳗弧菌和嗜水气单胞菌的免疫力,并且免疫和攻毒的途径可能是影响免疫保护效果的因子.本研究旨在为鳗弧菌与嗜水气单胞菌引起的鱼类疾病防治提供技术支撑.  相似文献   

14.
Abstract. The growth of the aquaculture industry and the general awareness of the environment have increased the concern of' the environmental impact from aquaculture.
As fish farms are open systems, all material that is not harvested as fish is released to the environment. The most important effluents are solid particles like feed and faeces, dissolved substances like nutrients and excretion products, and antibacterial agents.
The effect of these substances varies with their nature and quantity and with local conditions. Production and biomass of phytoplankton seem to be little influenced. The benthic community beneath and close to the cages is often altered. At poorly flushed sites the sea-bed may be anoxic and methane and hydrogensulphide are released from the sediments. Wild fauna, like fish, otters and birds are attracted to the farms.
The respiration and excretion of the fish directly influence water quality. Usually the oxygen tension is somewhat reduced in the net cages, while the concentration of ammonia is elevated in the net. Such conditions are assumed to influence fish growth and health.
Most of the antibiotic agents used in fish farming are persistent and may remain in high concentrations in the sediments up to one year after medication. The frequency of resistant bacteria in the sea-bed is normally increased, and there is a temporary drop in sediment metabolism after medication. Wild fish have been found to have high residues of antibiotic agents.
The organic loading of the sea-bed, the evolution of resistant bacteria and residues in the wild flsh are considered to be the most severe environmental impact of aquaculture. These are all associated with effluent of large particles, and thus mainly restricted to the site area.  相似文献   

15.
Sustainable and long-term growth of the aquaculture industry should involve both ecologically sound practices and appropriate resource management. The increasing economic dimension of Mediterranean aquaculture is opening new economic niches and may be a valid support to reduce the pressure of traditional fisheries. Aquaculture practices can also lead to modifications of coastal habitats through the impact of wastes of land-based and open-sea mariculture facilities. In addition to these aspects which place a direct pressure on aquatic ecosystems and wild fishery resources, a wide range of environmental contaminants, such as chemicals used in farming operations, can accumulate in farmed organisms and put fish health and quality at risk. Thus, as aquaculture makes its transition to a major food-producing sector, proper assessment and control of environmental impacts and food safety awareness are becoming increasingly important. The development of simple tools able to monitor the extent of environmental and biological impacts associated with farming operations at various levels of biological complexity from the ecosystem to the organism level is required. Although a number of techniques for assessing the environmental and biological impact of pollutants in natural ecosystems are available, the development of practical and validated tools is sorely needed in aquaculture.  相似文献   

16.
A prebiotic is a non‐digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or the activity of one or a limited number of bacteria in the colon. Despite the potential benefits to health and performance as noted in various terrestrial animals, the use of prebiotics in the farming of fish and shellfish has been less investigated. The studies of prebiotics in fish and shellfish have investigated the following parameters: effect on growth, feed conversion, gut microbiota, cell damage/morphology, resistance against pathogenic bacteria and innate immune parameters such as alternative complement activity (ACH50), lysozyme activity, natural haemagglutination activity, respiratory burst, superoxide dismutase activity and phagocytic activity. This review discusses the results from these studies and the methods used. If the use of prebiotics leads to health responses becoming more clearly manifested in fish and shellfish, then prebiotics might have the potential to increase the efficiency and sustainability of aquaculture production. However, large gaps of knowledge exist. To fully conclude on the effects of adding prebiotics in fish diets, more research efforts are needed to provide the aquaculture industry, the scientific community, the regulatory bodies and the general public with the necessary information and tools.  相似文献   

17.
Aquaculture is one of the fastest growing industries in the world. The need for enhanced disease resistance, feed efficiency, and growth performance of cultured organisms is substantial for various sectors of this industry. If growth performance and feed efficiency are increased in commercial aquaculture, then the costs of production are likely to be reduced. Also if more fish are able to resist disease and survive until they are of marketable size, the subsequent cost of medication and overall production costs would be reduced drastically. It has been documented in a number of food animals that gastrointestinal microbiota play important roles in affecting the nutrition and health of the host organism. Thus, various means of altering the intestinal microbiota to achieve favorable effects such as enhancing growth, digestion, immunity, and disease resistance of the host organism have been investigated in various terrestrial livestock as well as in humans. Dietary supplementation of prebiotcs, which are classified as non‐digestible food ingredients that beneficially affect the host by stimulating growth and/or activity of a limited number of health‐promoting bacteria such as Lactobacillus and Bifidobacter spp. in the intestine, while limiting potentially pathogenic bacteria such as Salmonella, Listeria and Escherichia coli, have been reported to favorably affect various terrestrial species; however, such information is extremely limited to date for aquatic organisms. Effects of probiotics, defined as live microbial feed supplements, on gastrointestinal microbiota have been studied in some fishes, but the primary application of microbial manipulations in aquaculture has been to alter the composition of the aquatic medium. In general, the gastrointestinal microbiota of fishes including those produced in aquaculture has been poorly characterized, especially the anaerobic microbiota. Therefore, more detailed studies of the microbial community of cultured fish are needed to potentially enhance the effectiveness of prebiotic and probiotic supplementation. This review summarizes and evaluates current knowledge of intestinal microbial ecology of fishes, the various functions of this intestinal microbial community, and the potential for further application of prebiotics and probiotics in aquaculture.  相似文献   

18.
Ethoxyquin (EQ) has been used as an antioxidant in livestock, aquaculture and pet foods. Animal food safety law has established the upper limit of EQ in animal feed at 150 mg kg−1. However, the risk of EQ at the approved level for aquaculture feed (150 mg kg−1) to fish health is unknown. Here, we examine the effect of EQ on the immunity of tilapia ( Oreochromis niloticus ). EQ concentration in the blood reached 0.16 mg L−1 in fish fed EQ at the approved level. This level of EQ inhibited phagocytic activity of leucocytes in vitro and antibacterial activity of whole blood in vivo . Furthermore, pyknosis in the liver was observed throughout the duration of feeding. However, after 30 days of experimental challenge with feed containing 150 mg kg−1 of EQ, no significant difference was observed in mortality. Although EQ at the approved level in feed causes immunosuppression in fish, the severity of immunosuppression does not lead to a lowering of disease resistance for short feeding periods.  相似文献   

19.
为探讨我国稻田养殖克氏原螯虾的微量元素含量水平和食用安全性,利用电感耦合等离子体质谱法(ICP-MS)分析了湖北、湖南和安徽3省156份稻田养殖克氏原螯虾肌肉样品中24种微量元素的含量,并采用污染指数法、暴露评估和非致癌风险评价法进行污染评价和膳食评估。结果显示,在克氏原螯虾样品的24种微量元素中,Li、Be、Tl和U这4种元素未检出,Ni、Cd和Pb这3种微量元素检出率低于50%。有16种元素含量在安徽与其他两个产地间存在显著差异,而其中5种元素在3个不同产地间存在显著差异。所有克氏原螯虾样品中,有害重金属元素As、Cu、Pb、Cd和Cr的污染指数均小于0.2,处于正常背景值水平。研究表明,21种微量元素的总目标危害系数TTHQ=3.672<10,有害元素的THQ均在可接受范围,长期食用对人群没有明显的健康风险,但营养元素Fe的摄入值得关注。  相似文献   

20.
I Qin  D A Culver  N Yu 《Aquaculture Research》1995,26(12):911-920
Alfalfa meal as a source of organic fertilizer was used in a series of pond, enclosure and laboratory experiments to determine its effect on bacteria, algae and water quality. Bacteria and flagellate algae were increased, whereas nonflagellate algae were not significantly affected by organic loadings. Bacterial and algal turnover rates we re 1.9-2.7 times daily and 0.18-0.22 times daily at 20-25oC, respectively. Oxygen consumption rates were enhanced by increasing organic input or temperature. Dissolved oxygen in ponds with organic fertilizer was significantly lower than that in ponds without organic input. Because of low N and P content and high oxygen consumption, organic fertilizer alone is unlikely to provide adequate nutrients for algae and sufficient oxygen for fish. To stimulate the growth of food organisms for fish in aquaculture ponds, a combined use of inorganic and organic fertilizer is recommended, but the amount of organic fertilizer should be determined with care to avoid water quality deterioration. The amount of 10mg alfalfa 1?1 wk?1 is considered the upper safety limit for organic fertilization. The nitrogen and phosphorus ratio should be kept weekly at 20:1 by weight to promote the development of food organisms in ponds.  相似文献   

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