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1.
Multi-criteria evaluation approach to GIS-based land-suitability classification for tilapia farming in Bangladesh 总被引：1，自引：0，他引：1
M. Shahadat Hossain Sayedur Rahman Chowdhury Nani Gopal Das M. Moshiur Rahaman 《Aquaculture International》2007,15(6):425-443
Site selection is a key factor in any aquaculture operation, because it affects both success and sustainability. It can, moreover,
solve conflicts between different activities, making rational use of the land. This study was conducted to identify suitable
sites for development of Nile tilapia (Oreochromis niloticus) farming in Sitakunda Upazila (sub-district), Bangladesh, using GIS-based multi-criteria evaluation of water and soil quality,
topography, infrastructure and socio-economic factors. ASTER image and eighteen thematic layers were analyzed using ENVI and
ArcView software to identify the suitable areas for tilapia farm development. A constraint layer was used to exclude areas
from suitability maps that cannot be allowed to implement tilapia farming. A series of GIS models were developed to identify
and prioritize the most suitable areas for tilapia farming. The output of the model clearly indicates the location and extent
of tilapia farming areas on different suitability scales, i.e. most suitable (7,744 ha), moderately suitable (2,479 ha), and
not suitable (838 ha). Model outputs were assessed against field verification data, and were consistent. Because existing
aquaculture covers only 1,540 ha of land in the study area, the potential for expanding tilapia farms should take into consideration
socio-political and environmental issues. The results are encouraging in terms of tilapia culture development and suggest
that grassland–agriculture areas could be used for sustainable development of tilapia farming to diversify the economic activities
of rural communities. 相似文献
2.
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. 相似文献
3.
Biosecurity in Shrimp Farming: Pathogen Exclusion through Use of SPF Stock and Routine Surveillance 总被引：1，自引：0，他引：1
Biosecurity, as it is being applied to shrimp aquaculture, may be defined as the practice of exclusion of specific pathogens from cultured aquatic stocks in brood stock facilities, hatcheries, and farms, or from entire regions or countries for the purpose of disease prevention. To make a biosecurity program a functional concept in shrimp aquaculture, the relevant risks should be identified and the appropriate biosecurity measures put into practice to mitigate those risks. Examples of biosecurity measures put into place for this purpose may include such basics as site selection when the intent is to locate a new shrimp culture facility in an area where certain diseases are not enzootic. Standard facilitylfarm operating procedures can be adapted to minimize the risks of disease introduction and spread within a facility through such concepts as pretreatment of all source water, and reduced or “zero” water exchange. Stocking shrimp culture facilities with domesticated shrimp stocks that are free of specific diseases (“Specific Pathogen Free” or SPF) and or with stocks resistant to specific disease agents (SPR) is perhaps the most important single component of a biosecurity program. The example set by the development of domesticated SPF stocks of Litopenaeus vannamei has helped to make biosecure shrimp culture feasible. The development of these and other SPF stocks, and the diagnostic methods to develop and monitor them for specific diseases and disease causing agents, have been milestones in the development of the international shrimp farming industry in recent years, and it has contributed to the species rivaliig Penaeus monodon as the dominant farmed shrimp species. The regular monitoring (surveillance) of shrimp stocks in biosecure culture facilities is a necessary component of a biosecurity plan, as is having in place a contingency plan for disease containment and eradication should a breach occur in the physical and managerial components of a biosecure facility and a targeted disease occur. 相似文献
4.
This paper presents the development of a simple and generally applicable hydrodynamic method for the estimation of production carrying capacity (PCC) of coastal finfish cage aquaculture. Dimensional analysis was used to find significant and general interdependencies between the hydrodynamics at fish farm locations and particulate wastes deposited on the seafloor by fish farms. Modeled ratios of deposition to emission of particulate wastes underneath fish farms were found to be primarily a function of the flow Reynolds numbers at the farming locations and the non-dimensional settling velocity of emitted wastes. In the non-dimensional model, farming conditions include daily feed rate, proportion of unconsumed feed, and carbon content in feed and fish feces. The relationship can be used to estimate the PCC of floating net cages imposing a threshold value for deposition. Results of in-situ assessments of the benthic impacts of several fish farms in an aquaculture site in the northwest of Bali, Indonesia were used to validate and demonstrate the effectiveness of the method. Predicted results were able to clearly identify fish farms operating beyond ecologically sustainable carrying capacity. The proposed method has broad applicability and could help make decisions regarding the estimation of production potential of individual farms in pristine areas, for providing first estimates in sites that have scarce data, and for assessment, expansion, and optimization of the currently operating aquaculture sites in Southeast Asia, China and potentially other data-poor island nations. As the method relies on dynamic models, it enables straightforward assessments over the entire aquaculture region. 相似文献
5.
M. Abdus Salam Lindsay G. Ross C. M. Malcolm Beveridge 《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):477-494
The present study identifies and quantifies appropriate sites for brackish water aquaculture development in southwestern Bangladesh using remote sensing, GPS and geographical information systems (GIS). A colour composite Landsat TM image from 1996 covering the southwestern part of Bangladesh was used to identify the extent of brackish water and to classify land use. The remotely sensed data were complemented by secondary data digitised from a range of sources, including hard copy maps, to create a spatial database that included environmental and infrastructural data. A series of GIS models were developed in order to identify and prioritise the most suitable areas for brackish water shrimp and crab farming. Using qualitative and quantitative output from the models, the benefits of shrimp and crab farming and alternative land uses in the Khulna region were compared, based on gross production, economic output and employment potential. Comparisons were made of brackish water shrimp and crab culture with moderately saline-tolerant tilapia and prawn culture, freshwater carp culture and traditional rice production systems. Shrimp was identified as the most capital intensive and risky production system. Earnings per hectare were a little higher for shrimp culture than for crab culture. The present study demonstrates the usefulness of GIS as an aquaculture planning tool in a region where natural resources are already under considerable pressure. 相似文献
6.
Kiet T. Nguyen Timothy C.G. Fisher 《Aquaculture Economics & Management (Blackwell Science)》2013,17(4):325-343
This article investigates the efficiency of intensive, semi-intensive, and extensive shrimp farming practices as well as the difference between the upstream and downstream efficiency of shrimp farms in the Mekong River Delta (MRD), Vietnam. Our article is the first to compare the efficiency of the 3 shrimp practices and investigate the difference between the efficiency of downstream and upstream farms. The efficiency of shrimp farms is measured using group-frontier and meta-frontier analysis on a sample of 292 farms. The results show that, on average, shrimp farms are inefficient; extensive farms are more efficient than intensive and semi-intensive farms; and, controlling for key socio-economic factors, upstream farms are more efficient than downstream farms, suggesting that pollution from upstream farms may influence shrimp farm efficiency. The results give some direction for improvement and some evidence to shrimp farmers and policymakers in the MRD to take the pollution problem seriously and find solutions for more sustainable development. 相似文献
7.
8.
Socio-economic impacts of shrimp culture 总被引：8，自引：0，他引：8
J H Primavera 《Aquaculture Research》1997,28(10):815-827
Farmed shrimp contributed 27% of total world shrimp production in 1995 with a volume of 712 000 tonnes. Undoubtedly, the shrimp culture industry earns valuable foreign exchange for developing countries and generates jobs across the industry from fry gatherers to growers and processors. However, grave socio-economic consequences – including conversion, expropriation and privatization of mangroves and other lands; salinization of water and soil; decline in food security; marginalization of coastal communities, unemployment and urban migration; and social conflicts – have followed in the wake of, shrimp farm development in the Philippines and other tropical countries. The paper focuses on mangrove ecosystems: the valuation and cost-benefit analysis of their goods and services, and the mangrove-offshore fisheries connection. Research gaps in these areas and the need to internalize the ecological and socio-economic costs (‘externalities’) of shrimp farming are highlighted. Other recommendations include mangrove conservation and rehabilitation, enforcement of existing legislation, and introduction of environment-friendly aquaculture within the broader framework of community-based, integrated coastal area management, e.g. the traditional, extensive polyculture ponds in Indonesia. 相似文献
9.
Hatim Albasri Sophia L. Sagala Indra Pratama Jesmond Sammut 《Aquaculture Research》2020,51(4):1464-1479
Aquaculture, particularly marine‐based production, is one of the fastest growing industries in Indonesia. Indonesia's competitiveness in the trade of aquaculture products is constrained by a lack of research and development (R&D) of new aquaculture species candidates. Mariculture has the greatest potential due to Indonesia's vast marine resources and archipelagic geography. Although there are over 3,000 species of marine fish in Indonesia, only 14 species have been widely cultured, largely finfish. Production is dominated by shrimp, groupers and milkfish. Traditionally, candidate species for mariculture in Indonesia and elsewhere have often been selected on their market value before their biological suitability for culture has been established leading to partially successful R&D efforts or even failure. The present study developed a framework for selecting marine fish species to support mariculture R&D in Indonesia based on an improved analytic hierarchy process (AHP). The approach combined various quantitative and qualitative data and involved different R&D stakeholder groups in the selection process. Ten species that had not been previously researched for their aquaculture potential were identified. The modified approach addressed the interaction complexity of criteria and different preferences across the stakeholders. The involvement of different stakeholders in the selection process not only ensured acceptance of the selected species for further research, but also tested the validity and consistency of the method used in this study. The methodology has relevance for mariculture globally given that efficient candidate selection can help focus efforts and investment in mariculture R&D. 相似文献
10.
Comparing Profits from Shrimp Aquaculture with and without Green-Water Technology in the Philippines
To reduce disease impact, Philippine farmers developed the green-water (GW) system, which has been spreading rapidly since 2008. In the most applied GW-system, the shrimp pond receives water from a reservoir stocked with tilapia. We collected financial data on GW and non-GW systems from farms having similar management and environmental context. All farms had more than one pond; the average pond area was < 1 ha, and total pond areas per farm ranged from 1.4 to 139 ha. The total variable and fixed costs per ha of shrimp pond were not different for GW and non-GW farms, but on GW farms the cost per kg of shrimp produced was lower. The latter was higher than the 2009 market price of 30 g shrimp for non-GW farms mainly. In GW farms the cost of seed was lower, and survival rates and individual shrimp weights at harvest were higher for an equally long culture period. 相似文献
11.
The present study focuses on the development of a standard methodology for selection of suitable sites for offshore (exposed) marine fish‐cage farming (floating cages) of seabream (Sparus aurata) and seabass (Dicentrarchus labrax) in an island environment, using Tenerife as an example. Site selection is a key factor in any aquaculture operation, affecting both success and sustainability and can solve conflicts between different activities, making a rational use of the coastal space. Site selection was achieved by using geographical information systems (GIS)‐based models and related technology to support the decision‐making process. The framework for spatial multicriteria decision analysis used in this study began with a recognition and definition of the decision problem. Subsequently, 31 production functions (factors and constraints) were identified, defined and subdivided into eight submodels. These were then integrated into a GIS database in the form of thematic layers and later scored for standardization. At this stage, the database was verified by field sampling to establish the quality of data used. The decision maker's preferences were incorporated into the decision model by assigning weights of relative importance to the evaluation under consideration. These, together with the thematic layers, were incorporated using multicriteria evaluation techniques and simple overlays to provide an overall assessment of possible alternatives. The integration, manipulation and presentation of the results by means of GIS‐based models in this sequential and logical flow of steps proved to be very effective for helping the decision‐making process of site selection. Tenerife has very favourable environmental conditions for culture of marine fish and there are no totally unsuitable sites for cage farming identified in this study. On the other hand, there are few very suitable sites (high scores) either, principally due to the heavy use of the coastline and the conflicts between different users. From the 228 km2 of available area for siting cages in the coastal regions with depth less than 50 m, the total area suitable for siting cages (scores 6–8) was 37 km2. There are only 0.51 km2 of very suitable areas (score 8) and approximately 5.37 km2 of suitable (score 7), most of these being located in the southeast of the island. These relatively small areas of suitability should be put into the context of the wider use of the coastal environment around Tenerife. 相似文献
12.
A review on the morphology, molecular characterization, morphogenesis and pathogenesis of white spot syndrome virus 总被引：5，自引：0，他引：5
Escobedo-Bonilla CM Alday-Sanz V Wille M Sorgeloos P Pensaert MB Nauwynck HJ 《Journal of fish diseases》2008,31(1):1-18
Since it first appeared in 1992, white spot syndrome virus (WSSV) has become the most threatening infectious agent in shrimp aquaculture. Within a decade, this pathogen has spread to all the main shrimp farming areas and has caused enormous economic losses amounting to more than seven billion US dollars. At present, biosecurity methods used to exclude pathogens in shrimp farms include disinfecting ponds and water, preventing the entrance of animals that may carry infectious agents and stocking ponds with specific pathogen-free post-larvae. The combination of these practices increases biosecurity in shrimp farming facilities and may contribute to reduce the risk of a WSSV outbreak. Although several control methods have shown some efficacy against WSSV under experimental conditions, no therapeutic products or strategies are available to effectively control WSSV in the field. Furthermore, differences in virulence and clinical outcome of WSSV infections have been reported. The sequencing and characterization of different strains of WSSV has begun to determine aspects of its biology, virulence and pathogenesis. Knowledge on these aspects is critical for developing effective control methods. The aim of this review is to present an update of the knowledge generated so far on different aspects of WSSV organization, morphogenesis, pathology and pathogenesis. 相似文献
13.
Recent insights into host–pathogen interaction in white spot syndrome virus infected penaeid shrimp 
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下载免费PDF全文 Viral disease outbreaks are a major concern impeding the development of the shrimp aquaculture industry. The viral disease due to white spot syndrome virus (WSSV) observed in early 1990s still continues unabated affecting the shrimp farms and cause huge economic loss to the shrimp aquaculture industry. In the absence of effective therapeutics to control WSSV, it is important to understand viral pathogenesis and shrimp response to WSSV at the molecular level. Identification and molecular characterization of WSSV proteins and receptors may facilitate in designing and development of novel therapeutics and antiviral drugs that may inhibit viral replication. Investigations into host–pathogen interactions might give new insights to viral infectivity, tissue tropism and defence mechanism elicited in response to WSSV infection. However, due to the limited information on WSSV gene function and host immune response, the signalling pathways which are associated in shrimp pathogen interaction have also not been elucidated completely. In the present review, the focus is on those shrimp proteins and receptors that are potentially involved in virus infection or in the defence mechanism against WSSV. In addition, the major signalling pathways involved in the innate immune response and the role of apoptosis in host–pathogen interaction is discussed. 相似文献
14.
E. Hempel 《Aquaculture International》1993,1(1):2-19
World aquaculture production in 1990 reached some 15 million tonnes, and predictions indicate that future production will reach 19.6 million tonnes by 2000, 37.5 million tonnes by 2010, and 62.4 million tonnes by 2025. Meanwhile, world fisheries production from capture will remain stable at about 100 million tonnes. Thus, all future increase in seafood supplies will have to come from aquaculture.Possibilities for development of aquaculture exist in a number of areas around the world. Technology and natural conditions determine the choice of sites and species to be produced, but current research indicates that a number of new species will be added to the present aquaculture production in the coming years. However, well-known species such as carp, tilapia, trout, salmon, turbot, halibut, cod, and sturgeon will be the most important in the immediate future. Among the crustaceans, shrimp will continue to be an important item, as will various kinds of gastropods and bivalves.Regions with a particular suitability for development of aquaculture include Africa, Asia, and Latin America. Freshwater aquaculture may also be developed on a larger scale in the former Eastern European countries, including the former Soviet Union, but here (and in Africa), political and economic constraints will slow down development for the next decade. A major constraint for development of aquaculture in Africa is the lack of infrastructure, as well as political problems, slow or deficient bureaucracies, and to some extent pollution. In Eastern Europe, development will be hindered by the lack of capital, and uncertainty about the political and economic development. Eastern Europe also has a major environmental problem, which may limit growth within this field. In Asia, space and availability of suitable sites are becoming a problem, as are pollution, diseases, and in some cases overproduction.A general constraint to global development of aquaculture may be price fluctuations, which affect the investment willingness of interested investors. This question must be seen in connection with the economics of operation. As new species are being launched, there is usually a short period of high profits, followed by a period of price reductions, and the collapse of several operators. After such turbulence, serious operators with proper management survive, and go on to operate a reasonably profitable business. The mechanism seems to be true for all new business areas, and does create a problem for sustained investor interest in aquaculture development. 相似文献
15.
Decision making tool called Decision Making Tool for Identification of Optimal Location in Aqua farming development was developed using Visual Basic programming language for identification of optimal location for aquaculture farming development. Twenty-four input criteria to the tool were categorized into six broad heads of main-criteria namely: water (10 sub-criteria), soil (5 sub-criteria), support (2 sub-criteria), infrastructure (3 sub-criteria), input (1 sub-criterion), and risk factor (3 sub-criteria). In this tool, the optimal location was identified based on the objective function, which was derived from the combination of rank sum, pair-wise comparison, and Technique for Order Preference by Similarity to the Ideal Solution methods. Based on the objective function values, alternatives (or aqua farms) were ranked in descending order in a table. In order to validate the developed tool, the same alternatives were ranked in descending order according to the observed average yield value per hectare (ha) for the last three crops. Spearman’s rank correlation was used to assess the correlation between ranks obtained by the tool and ranks obtained based on average yield. It showed with 99% confidence that a significant correlation exists between ranks obtained by the tool and ranks obtained based on average yield. Developed tool appeared to be confident and robust in proof-of-concept application for aquaculture farming development in Kalla mandal with reference to shrimp farms, West Godavari district, Andhra Pradesh, India. 相似文献
16.
岛礁海域保护型人工鱼礁选址适宜性评价 总被引：1，自引：1，他引：0
为了提高人工鱼礁选址的有效性,实验以岛礁海域保护型人工鱼礁选址适宜性评价为例,基于多准则决策方法,结合专家系统、层次分析法、地理信息系统(GIS)空间分析对马鞍列岛海域进行了研究。通过文献综述和专家经验提取影响保护型人工鱼礁选址适宜性的主要准则(物理因素、生物因素和管理因素)和对应的次级准则(底部坡度、底质类型、海流、水深;渔获量、资源密度、幼鱼量、幼鱼扩散;与污染源距离、与航道距离、离岸距离)。通过两两比较法和层次分析法计算主要准则和次级准则的权重,结果显示,物理因素、生物因素和管理因素的权重分别为0.481、0.405、0.114。对应次级准则的权重为0.101、0.186、0.097、0.098、0.095、0.184、0.048、0.079、0.068、0.030、0.016。各准则图层叠加计算后的结果显示,马鞍列岛保护型人工鱼礁选址的适宜性具有空间异质性;海区底质类型、水深、资源密度与适宜性分布的对应分析表明,模型结果与适宜性准则的设置基本一致;高适宜性区域内已投放的人工鱼礁也表现出有效性。 相似文献
17.
Effects of Culture Area,Stocking Density,and Shrimp and Fish Polyculture on the Cost Efficiency of Hard Clam,Meretrix meretrix,Culture: A Case Study of Hard Clam Farms in Yunlin,Taiwan 下载免费PDF全文
下载免费PDF全文 Jung‐Fu Huang Ming‐Tao Chou Jie‐Min Lee Yung‐Hsin Cheng 《Journal of the World Aquaculture Society》2016,47(4):481-495
Using the hard clam farms in Yunlin, Taiwan as examples, this study analyzes the effects of culture area, stocking density, and shrimp and fish polyculture on the cost efficiency (CE) of hard clam farming. A data envelopment analysis (DEA) is used to estimate the farms' technical efficiency (TE), allocative efficiency (AE), and CE values. The findings show that the mean TE, AE, and CE values of hard clam farms are 0.74, 0.57, and 0.43, respectively. The TE value is higher than the AE value, which indicates that cost inefficiency is mainly attributable to poor AE. Tobit regression results suggest that there are positive relationships between CE and both culture area and operator experience. Hard clam stocking density and age of the operators have negative effects on CE. Hard clam culture areas larger than 2 ha and a stocking density of 1.1–1.2 million hard clams per hectare have higher CEs than smaller culture areas and smaller or larger stocking densities. The use of sand shrimp, white shrimp, kuruma shrimp, and grass shrimp for polyculture and the use of milkfish and silver sea bream for polyculture are both associated with high CEs. 相似文献
18.
This paper describes the use of a geographical information system (GIS) to construct environmental models for land-based aquaculture development in the State of Sinaloa, Mexico. Based on the source data, submodels were created focusing on three different themes: general environmental issues, water resources and water quality. Models enabled multicriteria and multiobjective decision making concerning site selection and location. In assessing site considerations these general models identified wider resource management options and solved conflicts of land allocation and land use between aquaculture and agriculture. Smaller-scale, more specific models enabled more detailed studies on environmental issues. 相似文献
19.
Hugues Lemonnier Alain Herbland Benoît Soulard 《Aquaculture (Amsterdam, Netherlands)》2006,261(3):1039-1047
The “Summer Syndrome”, a septicemic vibriosis caused by Vibrio nigripulchritudo, is responsible for one of the two main seasonal mortalities which affect shrimp aquaculture in New Caledonia. It was identified for the first time in December 1997 in an intensive shrimp farm (called farm DF) and has been enzootic ever since. The “Summer syndrome” affects shrimp during warm-season growout. Although the geographic area concerned is limited, it is a potential threat for the industry in that the disease could spread. Analysis of grow out data from 1991 to 2002 in this farm was carried out in order to characterize the disease and the environmental conditions in relation to mortality. Results of farm DF were compared to data from farms not affected by the disease (called farms HC). The “Summer syndrome” occurs during the warm season which is characterized by an increase in water temperature and sunny duration. This disease is characterized by simultaneously highest densities and weakest drying duration between crops in the farms studied. Between 1991 and 2002, the increase of feed input and nitrogen rate in feed has led to a significant increase of the growth rate over the years in farm DF. At the same time, water management has not changed and has induced an increase in environmental waste production. In consequence, an early eutrophication of water is observed, which is concomitant with the beginning of the mortality outbreaks. This could play a role by inducing directly or indirectly a stress for shrimp and/or a growth and/or virulence factors of the pathogen. 相似文献