I. INTRODUCTION
This Regional Study and Workshop on the Environmental Assessment and Management of Aquaculture Development (TCP/RAS/2253) was requested by governments of the Network of Aquaculture Centres in Asia-Pacific (NACA) and funded through the Tenchnical Co-operation Programme of the Food and Agriculture Organization of the United Nations (FAO). The project was launched in September 1992, with a planning meeting in Bangkok attended by National Environment Co-ordinators (NECs) nominated by participating governments. Following this planning meeting, the NECs undertook detailed country studies in preparation for the final workshop, held on 21–26 February 1994, at the Regional Office for Asia and the Pacific (RAPA) of FAO.
The final workshop was attended by 30 government officers from 16 countries in the region, as well as 40 other participants that included representatives of various international organisations, international and regional resource speakers, members of the TCP project team (an economist, environmental management specialist and legal expert) and observers from government agencies, non-government organisations and the private sector. The governments represented by their respective NECs and senior government planners included: Bangladesh; Cambodia; China; Hong Kong; India; Indonesia; Iran; Korea (Rep.); Lao PDR; Malaysia; Myanmar; Nepal; the Philippines; Sri Lanka; Thailand; and Vietnam. The NEC of Pakistan prepared a country report which was considered by the workshop. DPR Korea had participated in the planning meeting, but did not attend the final workshop. Participating international organisations included the World Health Organization (WHO), World Wide Fund for Nature (WWF) and United Nations Development Programme (UNDP). Regional institutes, agencies and projects included the ASEAN-EC Aquaculture Development and Co-ordination Programme (AADCP), Asian Wetland Bureau, Asian Institute of Technology, Asian Fisheries Society, Mekong Committee and UN ESCAP. Several private sector, non-government organisations and academic institutions from various countries were also represented.
The Workshop objectives were to: (i) identify methods for managing the environmental impact of aquaculture, including those impacts of environment on aquaculture and the impacts of aquaculture on the environment; and (ii) recommend to farmers, governments and regional and international organisations, the steps which should be taken to introduce methods to improve the environmental management of aquaculture. Technical discussions, held over four days, dealt with : (i) the results of the country studies, including case studies illustrating interactions between aquaculture and the environment; (ii) the regional overview prepared by the TCP project team on the basis of its country visits; and (iii) the outcome of consultation of the two working groups, constituted from the participants, to identify management options and make recommendations to resolve issues arising from various interactions between aquaculture and the environment -- at farm, government and regional levels. After considering the environmental issues facing aquaculture in the region and the management strategies used or proposed to address the problems, the workshop reached a set of conclusions concerning the environmental impacts of aquaculture development and adopted a comprehensive set of recommendations addressed to governments, farmers and supporting industries and international organisations.
II. CONCLUSIONS
During the workshop, it was apparent that far less precise and quantified information was available concerning the interactions between aquaculture and the environment than had been expected at the outset of the study. While the nature of the impacts is generally well known, knowledge of what caused the impact -- especially that suffered by aquaculture -- is often unquantified and speculative. Little is known of the environmental impacts caused by aquaculture, with most information -- even if recent -- anecdotal in nature. The degree of responsibility of aquaculture producers in recent serious disease outbreaks (mainly affecting shrimp farms) and their contribution to pollution of culture areas is also speculative.
Preventative management of environmental impacts at farm level is well known. Information on the legal framework for aquaculture is available. Aquaculture is often subject to a set of rules designed to manage the use of natural resources, such as water and land. These rules are seldom recapitulated in the form of a basic law for aquaculture and information about enforcement, and reasons for non-enforcement, is limited.
A. Inland aquaculture
Most types of inland aquaculture are not harmful to the environment. The potentially negative environmental impacts of freshwater aquaculture consist essentially of its contribution to aquactic pollution. However, the contribution of freshwater aquaculture to the pollution of inland waters is relatively harmless (mainly nutrients and organic matter) and insignificant in size. The few cases of freshwater aquaculture contributing to localised water pollution involve cage and pen culture in lakes and reservoirs. The extent of impacts on aquatic biodiversity (through introduction of exotic fish species) are poorly quantified and inland wetland impacts are considered minor compared to those for other (non-aquaculture) users. Freshwater aquaculture also suffers from water pollution and encroachment by competing water users. The pollution suffered by freshwater aquaculturists is caused by larger industries or non-point sources, which individual aquculturists are mostly powerless to deal with. The state seldom considers it justified to do so on their behalf, and aquaculturists generally have to find solutions to such problems at farm level.
B. Coastal aquaculture
1. Crustacean (shrimp)
Coastal shrimp farmers can cause environmental impacts on coastal lands and adjacent inshore waters. They also suffer environmental impacts; a part of which is caused by neighbouring shrimp farmers. The nature of the impact of aquaculture on land-based activities (e.g. agriculture, use of mangroves, groundwater supplies, changes in rights of access to land and water) and on coastal waters (e.g. fishing, tourism) in the major shrimp producing countries (Thailand, China, Indonesia, India, Philippines and Vietnam) is better known than its magnitude or economic importance. The environmental damage suffered by shrimp farmers is more precisely known, with regional losses over the past few years estimated as in excess of US $ 1 billion - mostly caused by serious outbreaks of shrimp disease. These losses have been attributed to self-pollution due to inappropriate pond management and the use of waters polluted by neighbouring shrimp farms. Studies in the Bohai in China and the Upper Gulf of Thailand indicate that shrimp farms are a minor contributor to pollutant loads in these water bodies.
In general, national administrations have not used the legal framework available to manage -- mainly through regulation and site selection -- the impact of shrimp farming on the environment. Shrimp farmers have been the originators of improvements in management of the impacts suffered by, and impacts generated by, shrimp farming. Impacts can be reduced through a combination of site selection and on-farm technology and management.
2. Finfish
Finfish farmers in coastal waters may cause environmental impacts, they also suffer from the impacts of non-aquaculturists -- mainly physical impacts such as water pollution and access to culture areas. Cage farms are more vulnerable to environmental problems than ponds. Impacts on the environment may include: physical impacts (water pollution and sedimentation); impacts on aquatic biodiversity (mainly use of wild seed for stocking of cages); and encroachment on access. The magnitude of the impacts on the environment is small compared to other users, but effects on biodiversity and water quality may be locally important. Any negative impacts on water quality and sediments can be managed through zoning of culture areas, and improved farm management. The development of hatcheries to supply juveniles might reduce risks to aquatic biodiversity from over-harvesting of wild stock, that may also affect non-target species.
3. Mollusc and seaweed
Environmental problems affecting seaweed culture are minimal. The culture of seaweed generally occurs without adverse environmental impacts; only occasionally are adverse impacts recorded, mainly through the effects of water pollution on seaweed farms, or through overstocking of culture areas.
Mollusc culture, with few exceptions, does not generate significant negative impacts on the physical environment. Management practices developed in the Republic of Korea demonstrate that where negative impacts occur -- principally sedimentation of culture areas -- they can be appropriately handled. As molluscs are normally cultured in open coastal waters, they are subject to the negative impacts from aquatic pollution and “red tides”. In view of the difficulty at present to manage red tides (the causative mechanisms are not well known), their impact may only be managed through: (i) zoning of culture installations; (ii) early warning systems; and (iii) insurance schemes. Depuration of molluscs may be used to control impacts from product contamination on public health, although this may be constrained by economic considerations.
III. RECOMMENDATIONS
The adopted workshop recommendations cover actions for governments, the private sector (including farmers and support industries) and international organisations. The full statement of the adopted recommendations appears in the Workshop Report. The recommendations may be summarised as follows:
A. Governments are recommended to take the following actions:
Strengthen national policy on aquaculture and identify a responsible agency for this task. Promote co-operation among government units and the public in the planning and operation of aquaculture units;
Establish a legal framework to enhance management of aquaculture in relation to the environment, and to reduce regulatory inefficiencies and costs to the industry;
Prevent the transfer of exotic species, except when in compliance with international codes of practice;
Conduct baseline surveys of aquaculture sites before major aquaculture development;
Monitor long term environmental changes after aquaculture development;
Adopt standard methodologies for aquaculture and environmental research;
Protect spawning and nursery grounds and identify and establish protected areas for the conservtion of aquatic biodiversity;
Develop human resources, including farmers, extension workers, policy makers, planners and scientists, for the planning and operation of sustainable aquaculture;
Enchance environmental awareness among aquaculturists and manufacturers of feeds, chemicals and drugs, and engage in close co-operation with farmers through on-farm reserach and other participatory activities;
Compile information on the environmental aspects of aquaculture for utilisation by government and industry sectors;
Support aquaculture policy development by strengthening research in:
B. Farmers and supporting industries are recommended to take the following actions:
Create greater awareness of environmental issues related to aquaculture;
Monitor farm operations to enable evaluation and improvement;
Form representative groups committed to enchancing performance and interacting with government, research and extension agencies;
Initiate and be more actively involved in on-farm research.
C. International organisations are recommended to take the following actions:
Support the formulation or reorientation of national aquaculture policy, giving a higher priority to environmental management and resource protection and allocation;
Strengthen regional and international co-operation to enchance environmental management in aquaculture and economic evaluation of impacts;
In the region, NACA should take a leading role in exchange of information, research cooperation and training, in collaboration with FAO and other organisations. Among the priority actions at the regional level, to support the governments in their national efforts, NACA should:
establish links with other international agencies with activities relevant to aquaculture for dissemination of information to governments.
Support a regional project involving detailed case studies, or local area planning exercises, covering the major aquaculture systems and environments;
Support regional research projects to:
nutrient requirements of important species and quality standards for feeds.
Aid governments to set up national centres or protected areas for germplasm collection and maintenance;
Establish regional training programmes in environmental management of aquaculture.
