The use of a geographical information system for land-based aquaculture planning

Site selection for aquaculture planning is a complex task involving the identification of areas that are economically, socially and environmentally suitable, available to aquaculture and commercially practicable. This paper reports upon a study into the use of a geographic information system (GIS) to assist in aquaculture planning. Using a case study in the site selection for land‐based shrimp farming within the Australian coastal zone, we demonstrate that a GIS has potential to assist aquaculture planning. Our analysis is based on a sequential, two‐stage approach. The first stage eliminates the grossly unsuitable portion of the study area through a preselection with low resolution, cheap and easily available data. The second stage then focuses on and ranks the remaining area using high resolution, possibly more expensive data. Finally, we use the GIS to present the results of the analysis in an easily accessible form.     

A future vision for disease control in shrimp aquaculture

Aquaculture is the fastest‐growing animal production sector, and shrimp production already exceeds that of the capture fishery. Viruses and bacteria account for the majority of disease losses for shrimp farmers. Viral pandemics in the mid 1990s and, more recently, a bacterial pandemic from 2009 to 2015 have led to the conclusion that future, sustainable shrimp aquaculture will depend on the development of more efficient, biosecure production facilities that cultivate specific pathogen‐free (SPF) shrimp, genetically improved for growth and disease tolerance or resistance. Major requirements for development, maintenance, and use of SPF stocks in aquaculture are effective pathogen surveillance and disease prevention methods. When protective measures fail and diseases occur in production ponds, there are currently only a few approved and practical therapeutic methods available for use with bacterial pathogens and none so far for viral pathogens. To improve existing methods of prevention and therapy and to develop new ones, research is being carried out on the nature of shrimp–pathogen interactions. Promising results have been obtained at the laboratory level for possible applications involving the use of immunostimulants for “immune priming” or “trained immunity” of RNA interference and of endogenous viral elements. Some of these promising new directions are discussed.     

Sustainable aquaculture: developing the promise of aquaculture

As experience with aquaculture grows worldwide, the concept of sustainable aquaculture is increasingly recognized to incorporate both spatial and temporal dimensions of environmental, economic, and social parameters. Practitioners have discovered that sustainable aquaculture must not only maximize benefits, but also minimize accumulation of detriments, as well as other types of negative impacts on natural and social environment. Therefore, sustainable aquaculture development must be advanced in a manner that is environmentally sustainable and that protects the quality of the environment for other users, while it is equally important for society to protect the quality of the environment for aquaculture. This paper provides a brief review of the worldwide aquaculture development in the last decade, and gives a few examples of sustainable aquaculture activities in the coastal areas that are using natural coastal habitats and ecosystems. Based on already existing national and international efforts to promote sustainable aquaculture, key recommendations are provided, including what should be the next proactive steps. This revised version was published online in August 2006 with corrections to the Cover Date.     

The benthic environmental footprint of aquaculture in the Eastern Mediterranean: Organic vs conventional fish farming

A field experiment was carried out in a fish farm of the Eastern Mediterranean in order to evaluate the benthic environmental footprint of the organic versus the conventional fish farming. The highest values of chl α were recorded at the conventional culture during both studied seasons. The organic matter and organic carbon rates recorded at the conventional culture were significantly higher than those observed at the organic culture in both studied seasons (p < .05). Furthermore, in all cases the quality characteristics of benthic community variables were optimum at the organic culture compared to the conventional one and similar to those of the control. SIMPER analysis showed that the maximum average dissimilarity occurred between organic and conventional culture, while the main contributor species for this dissimilarity was the polychaete Capitella capitata. Multidimensional scaling (MDS) ordination plot indicated clearly a separation of the organic and conventional fish farming during both studied seasons. K‐dominance curves revealed a clear difference in elevation, mainly during summer. M‐AMBI index showed a poor to moderate environment for conventional culture, while organic one was good to high and similar to the control site (high). The results indicated the lower environmental footprint of the organic fish farming compared to the conventional, demonstrating its potential as an important management tool, which could play a significant ecological role for the sustainability of aquaculture in the Mediterranean region.     

Testing of a pond‐side molecular diagnostic tool for the detection of white spot syndrome virus in shrimp aquaculture

White spot disease in penaeid shrimp is caused by the white spot syndrome virus (WSSV). It is the most economically important disease of farmed warm‐water shrimp, causing extensive economic losses estimated from $8 to $15 billion since its emergence in the 1990s. Early diagnosis of disease is critical in the management of outbreaks and to avoid crop losses. Diagnosis of white spot disease is generally carried out in centralized laboratory settings using molecular biology approaches. However, this mode of testing can be expensive and time consuming, requiring laboratory equipment, highly trained laboratory personnel, dedicated laboratory space, and long‐distance transportation of samples from field to lab. In‐field diagnostics are gaining credence as tools for rapid and early animal disease detection, allowing diagnosticians and farmers to potentially manage disease outbreaks from the pond side. In the present study, we describe the development and application of a new in‐field point‐of‐need diagnostic test and platform for the diagnosis of WSSV in remote settings (shrimp farms). We report its performance in laboratory and field settings and compare it with current gold‐standard diagnostic approaches. We discuss the potential benefits (and barriers to uptake) of applying such testing in the global shrimp farming sector.     

Shrimp farming in Latin America: Current status,opportunities, challenges and strategies for sustainable development

Abstract

Shrimp farming in Latin America and the Caribbean (hereinafter, LA&C) is a complex, diverse and dynamic activity, occurring in 22 out of 36 countries, producing 231,000 tons, valued at US$ 1.2 billion in 2002¹. Farmed shrimp represents 52% of all shrimp volumes produced regionally, and almost 18% of all shrimp and prawn (S&P, hereinafter) cultivated worldwide. Whiteleg shrimp (Litopenaeus vannamei) constitutes 91% of all shrimp farmed in LA&C and five nations, led by Brazil ‐formerly by Ecuador‐, comprise 82% of farmed production. Over 90% of LA&C shrimp production is exported (230,000 tons of end products from both aquaculture and wild origin valued at US$ 1.36 billion), generating a trade surplus of US$ 1.28 billion (2002).

Farmed shrimp could easily surpass 513,000 tons by 2030, more than doubling current regional figures (2.9% annual growth rate, compounded). However, competition with Asian countries, anti‐dumping accusations and other factors might limit the expansion process, which is increasingly determined by strategically important matters rather than by physical production constraints. Here, a ‘production‐driven’ process of past decades is being replaced by a ‘demand‐led’ situation, where market and marketing issues will increasingly influence the outcome of shrimp farming.

Growing market competition will continue to press prices down and industry will be forced into a permanent process to improve competitiveness. Here, development strategies include actions by governments and producer associations, promotional and marketing campaigns and the application of good management practices across the production and distribution chains.     

长江流域2种水产养殖模式的生命周期环境影响评价

本研究以长江流域内的池塘养殖和稻渔综合种养2种水产养殖模式为对象,应用生命周期评价方法,分析2种养殖模式对能源消耗(EU)、全球变暖潜势(GWP)、酸化潜势(AP)、富营养化潜势(EP)以及水资源消耗(WU) 5种环境指标的影响,并探究2种主要输入因子(饲料和电力供应)和养殖过程对各环境指标的影响,从而评价2种养殖模式对环境影响的差异。生命周期评价结果标准化处理和加权评估显示,稻渔综合种养模式的WU、EP、GWP、AP和EU值分别为11.650、0.770、0.141、0.096和0.003,总环境影响指数(TEII)为12.660;池塘养殖模式的WU、EP、GWP、AP和EU值分别为31.453、1.187、0.210、0.174和0.007,TEII为33.031。与稻渔综合种养模式相比,池塘养殖模式的各项环境指标均较高。对环境影响的贡献率分析表明,饲料供应对EU、GWP和AP的贡献率最高,EP主要受饲料供应和养殖过程的共同影响,而WU主要集中在养殖过程中,电力供应主要影响EU、GWP和AP。生命周期评价的结果表明,与池塘养殖模式相比,稻渔综合种养模式显示出更友好的环境效益,在我国...     

中国水产养殖污染物排放总量控制框架构建

近10年来,中国水产养殖业快速发展,产量大幅增加,随着绿色养殖概念的提出和总量控制制度的不断完善,水产养殖污染物排放强度明显下降,水产养殖污染物排放总量控制工作已见成效.本研究分析了水产养殖环境污染的产生与排放情况;总结了中国近年来为实现水产养殖污染物排放总量控制目标,在优化养殖布局、控制养殖环境污染、发展健康养殖和开...     

A review of production frontier analysis for aquaculture management

Abstract

This paper examines recent advances in production economics with special reference to efficiency measurement using production frontiers and its implications for aquaculture management. Compared with agriculture and other industries, the use of production frontiers in aquaculture is still very limited. However, in recent years several frontier applications in aquaculture have appeared in the literature, suggesting potential applications of these techniques in aquaculture. A synopsis of stochastic frontier production function model and data envelopment analysis (DEA), the two most popular approaches to efficiency measurement, is presented, followed by a review of recent frontier studies in shrimp, carp and tilapia production. The paper concludes with a brief discussion of future development and prospects of frontier applications for aquaculture management.     

Economic impacts of climate change: profitability of freshwater aquaculture in China

Aquaculture is threatened by the climate change which includes changes in temperature, precipitation, drought, storms and floods. The socio‐economic impacts of climate change on aquaculture are difficult to assess due to the uncertainties regarding the extent and rate of predicted changes. By including bond indexes as climate change variables, this study constructed a provincial‐level panel data set to estimate the profits and productivity of the Chinese aquaculture. Results indicate that aquaculture production has heterogeneous responses to climate change. However, the majority of climate variables, including extreme weather events and long‐term climate changes, strongly affect aquaculture profits. Future research needs to focus on designing suitable adaptation measures in an interdisciplinary setting to address the challenges from natural risks and economic volatility.     

Tolerance of the shrimp Litopenaeus stylirostris, Stimpson 1894, to environmental stress: interindividual variability and selection potential for stress-resistant individuals

Our study showed that osmoregulatory capacity (OC) of shrimp from the same clutch displayed interindividual variability. When environmental salinity decreases, this variability increases. Thus, at isoosmotic point (sea‐water salinity ≈26), the coefficient of variation calculated for measured OC was 2.7%, whereas it was 8.2% for sea‐water salinity ≈1.5. In terms of haemolymph osmolality, the interindividual difference can reach up to 45.8% for the same water salinity level. The mean OC of individuals that have survived a series of salinity and temperature shocks is significantly greater than the mean value recorded within their original population. This increase in OC was maintained beyond the one or two moulting periods that these shrimp experienced during our experiment.     

高效低碳——中国水产养殖业发展的必由之路

养殖种类不断增加,营养层次不断提高,集约化水平不断提升已成为我国水产养殖业总体发展的趋势,疾病流行、良种匮乏、污染严重、产品质量堪忧等诸多难题也随之而来。但从大尺度来审视,影响水产养殖近中期目标实现和可持续发展的主要问题则是水资源短缺、排污问题和产业发展对能源、鱼粉不断增大的需求。就产业主体而言,为保障我国的食物安全、实现我国CO₂减排目标,高效低碳模式是水产养殖业发展的必由之路。对未来10年甚或更长时期我国水产养殖发展目标的实现还会主要依靠一些相对简单且易被大众掌握的新技术的应用。积极发展碳汇渔业,特别是海水大型藻类和滤食性贝类的养殖,是实现水产养殖产业总体上走高效低碳道路的结构性保障。高效低碳养殖模式的建立需要大水域协同生产机制的体制保障,需要政府加强对养殖污染物排放监管的法律保障,需要生态学与经济学结合的学科保障。     

Aquaculture development in India: An economic overview with special reference to coastal aquaculture

Abstract

Coastal aquaculture emerged as a sunrise sector in India during the 1990s. It was identified as a sector full of promise for expanding exports and for adding to foreign exchange. The sector has more than fulfilled its promise and has more in store. This paper gives an overview of the role and development of fisheries in general and aquaculture in particular in India. Growth, sources of growth, contribution to national gross domestic product, impact on rural economy, socio‐economic impacts, generation of backward linkages, and export growth of coastal aquaculture in terms of composition, direction and penetration are reviewed. The paper concludes on an optimistic note for development of coastal aquaculture in the country with the streamlining of policy measures for production and marketing.     

Inflow and outflow water quality control in coastal aquaculture systems: a case study

Coastal water bodies are a particularly heterogeneous resource, typified by high spatial and temporal variability that could influence the aquaculture in coastal zones. However, the development of coastal aquaculture may produce negative impacts on the coastal area by the potential release of nutrients and organic matter that can be a source of pollution in receiving waters. The aim of this paper was to evaluate the performance of constructed wetland in controlling the dynamics of deoxygenating matter (organic matter and ammonia) and eutrophicating matter [organic matter and soluble reactive phosphorus (SRP)] in the waters entering (inflow) and flowing out (outflow) from a coastal aquaculture fish farm. We observed that constructed wetland systems are effective in removing fractions of total suspended solids, COD, total ammonia nitrogen and SRP contained in the inflow water with higher efficiency in the spring period (60.37%, 14.89%, 65.38% and 17.6% respectively) than in the summer period (45.10%, 8.06%, 32.43% and 8.00% respectively). Similar pattern was recorded for the treatment of the outflow waters, showing that the wetland system reduced most of the deoxygenating and eutrophicating matter produced as a consequence of feeding and fish metabolic activity. During the summer season, high algae mortality can reduce the performance of the wetland system in the outflow water control; this lower efficiency could be improved by controlling the biomass of algae by vegetation harvesting.     

Statistical aspects of aquaculture research: optimum block size in pond experiments

The sensitivity of any treatment comparisons in pond experiments is often limited by large variability among ponds. Standard techniques of increasing the number of replicate ponds to account for the large variability may be inappropriate as only a limited number of ponds may be available for any one experiment. This paper considers various ‘balanced incomplete block’ designs and compares their use with ‘completely randomized designs’ and ‘randomized complete block’ designs. With simulated data, it is shown that ‘balanced incomplete block’ designs can reduce the standard error of a treatment estimate by as much as 50%, and reduce confidence intervals by 25%, although increases of similar sizes may be experienced. The pattern of allocation of blocks to ponds by neighbour or by pond number shows no clear distinction in estimation improvement. Where missing ponds occur a large increase in imprecision may be experienced. These results are supported by data from non‐uniformity experiments. Further work is needed to explore block structures for specific types of treatment that may influence the patterns of variability to different extents.     

Review of climate change impacts on marine aquaculture in the UK and Ireland

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Stepwise function of natural growth for Scylla serrata in East Africa: a valuable tool for assessing growth of mud crabs in aquaculture

Predicting growth is critical in aquaculture, but models of growth are largely missing for mud crab species. Here, we present the first model of natural growth in juvenile and adult mud crabs Scylla serrata from East Africa using a stepwise growth function based on data on intermoult periods and growth at moult from field mark‐recapture, pond and laboratory studies. The results showed a sigmoid growth pattern in carapace width and suggest that S. serrata in East Africa will reach 300 g and sexual maturity ~9.9 months after settlement, and a commercial size of 500 g after 12.4 months. Analyses of the literature identified several issues with the common praxis to compare standard growth measures between aquaculture studies with different initial size or growing periods. Using the new growth function to estimate the proportional difference between modelled and obtained growth as an alternative method, we show that growth rates of S. serrata cultured in cage systems, which are dominant in East Africa, was <40% of the estimated natural growth and growth obtained in pond systems. The analysis also indicated that growth rates of S. serrata in Southeast Asia was over 50% higher compared with similar culture systems in East Africa, and that different species of mud crabs had large differences in growth rates. This study shows that growth in the present mud crab aquaculture systems in East Africa is below their expected potential. Further work is needed to identify the factors behind this observation.     

Environmental impact assessment as a management tool for the use of chemicals for fish farming in the UK

The paper begins by discussing the classification and use of chemicals for fish farming and the environmental impact assessment (EIA) regulations. EIA procedures for regulating chemicals through statutory authority are then discussed. Environmental assessment for fish farming can be a powerful management tool at both administrative and scientific levels.     

Agglomeration externalities and technical efficiency: An empirical application to the pond aquaculture of Pangas and Tilapia in Bangladesh

This article analyzes the effects of agglomeration externalities on productivity and efficiency by applying a stochastic production frontier model with a technical inefficiency model to the aquaculture industry. Agglomeration externalities refer to the costs and benefits to firms from clustering. Agglomeration studies within aquaculture have focused on the intensive salmon industry, whereas this study focuses on low-technology, extensive pond aquaculture, representing most farmers in the developing world and using Bangladesh as an empirical case. The results show that there is a positive externality effect of regional industry size on the production possibility frontier and a negative effect on technical efficiency. Farm density enhances efficiency and the farm proximity to output markets decreases efficiency. Thus, policies aimed at increasing aquaculture pond production in developing countries should consider farm locations and their access to input and output markets, all of which affect farm productivity and efficiency.     

Improving aquaculture in post‐tsunami Aceh,Indonesia: experiences and lessons in better management and farmer organizations

Coastal aquaculture in Aceh was severely affected by the Asian Tsunami in December 2004. Capacity building among stakeholders was one of the key activities implemented by various agencies during the post‐tsunami aquaculture rehabilitation and subsequent development phase. The main objective was improving production efficiencies and farmer incomes. This article describes the process of implementation of the approach and crop outcomes until the end of 2009. In 2009, 1135 farmers and their 1296 ponds were ‘organized’ in 27 clusters across 84 villages of three districts to implement better management practices (BMP). Interventions reduced the prevalence of shrimp disease outbreaks significantly in participating ponds (22.45%) compared with non‐participating ponds (62.64%). Among the normal harvested ponds, though there was no significant improvement in shrimp yield but costs of shrimp production were significantly reduced by 12.1% and benefit cost ratio was significantly increased by 0.523 points in normal harvested participating ponds compared with normal harvested non‐participating ponds. Multivariable logistic regression analysis with 27 independent variables including a set of BMP showed that many factors were significantly associated with the normal harvests, improved yield and profits. The study shows that simple management improvements can reduce risks and improve economic returns.