Guidelines for sustainable aquaculture and transport of live aquatic animals
From the earliest time, aquaculture and aquaculture-based fisheries were founded largely on non-indigenous species in different juvenile stages, including embryos, fry and fingerlings. Scientific bodies always advised a responsible system of screening, but this was seldom practised because of the stringent nature of the procedure and the lack of legislative support. This has resulted in the widespread occurrence of diseases and damage to the environment. Because of the improvement in transport facilities and the increase of aquaculture activities, it has become urgent to take action to prevent the unregulated transboundary movement of aquatic organisms.
Transfer or movement of an aquatic animal to an area within the established or historical range of the species is permissible. The role of health management is to reduce the risk arising from the entry of the pathogen and the spread of the pathogens to a manageable level.
Even though there is general agreement on the need for aquaculture and culture-based fisheries to meet the increasing demand for aquatic products, there is not such agreement on the procedures to be followed for sustainability in the intergeneric and social dimensions of aquaculture development. The absence of adequate scientific data cannot be used as a reason for postponing or failing to take conservation and management measures (FAO, 1995). Farmers and producers have achieved considerable experience that can be used for focusing research being carried out in several institutions and pilot farms, which may lead to scientific technologies for achieving sustainability.
Several national, regional and international institutions have undertaken the task of compiling and analysing the data acquired so far to prepare guidelines or codes of best practice for future use (FAO/NACA/1995; FAO, 1995; NENT, 1995; INFOFISH 1996; NATS, 1998; D’Abramo and Hargreaves, 1997; ADB/ NACA, 1998).
The guidelines prepared by various consultations, conferences and international organizations set out principles and standards to ensure effective ecological sustainability. Even though it is recognized that sustainability can be achieved only by the cooperative efforts of stakeholders, governments have a major role in promoting and facilitating this through enabling legislation and ensuring its implementation. Therefore most guidelines are addressed to sovereign state governments. The governments are required to enforce a planning mechanism for aquaculture development on the basis of the availability of resources. Zoning is undertaken on the suitability of areas, without conflict with other uses as far as possible. This may involve the balancing of benefits and detriments, including quantification of economic, environmental and social aspects. Planning of individual farms and farming in general should be based on impact assessments and formulation of mitigatory measures against adverse impacts, if any. Regular monitoring of these measures has to be promoted to minimize adverse ecological changes, and promote the rational use of resources shared by aquaculture and other legitimate activities.
Even though the codes of conduct are not mandatory, regular legislative measures, such as licensing of farms based on impact assessment, can assist the implementation of the guidelines, which are meant for long-term economic benefits to present and future generations. When designing and constructing farms it should be ensured that the livelihood of local communities and their access to fishing grounds are not impaired. Farms should not obstruct small-scale fishermen from carrying out their fishing activities and should add to their income by the trade in live fry and fingerlings. Pumping of groundwater to reduce the salinity of farms should be avoided, as also should salinization of adjacent agriculture land due to seepage through embankments.
Development agencies should be made responsible for the implementation of fish health management practices, including the use of vaccines and quarantine measures for exotic animal introductions. Safe and effective use of therapeutant hormones, drugs, antibiotics and other disease control chemicals should be permitted, including the observance of appropriate withdrawal periods of drugs and the containment of residues of chemicals and other toxins. The state agencies concerned should ensure the food safety of aquaculture products including genetically modified food organisms.
Even when farms are designed and operated according to scientific principles, clustering of sites without due accounting of their carrying capacity can damage the environment and affect their sustainability. Guidelines relating to coastal aquaculture and culture-based fisheries within transboundary aquatic systems emphasize the need for integrated coastal zone management. It is necessary that areas and resources important for different types of aquaculture are protected from being irreversibly allocated for other purposes. The best sectoral use for an area can perhaps be decided on the basis of the lowest pollution cost in relation to the value of the sectoral product. For example, in coastal zones shrimp farming can be more acceptable than agriculture on the basis of income generated per defined unit of pollution (Preston et al., 2001).
To facilitate the implementation of the guidelines for achieving the sustainability of aquaculture practices it is necessary that the various governmental agencies coordinate their activities. Regulations relating to the movement of exotic and genetically modified species can be implemented only through the willing cooperation of farmers, producers and local government officials. It has to be the responsibility of the state authorities concerned to protect the transboundary aquatic ecosystem by promoting sustainable aquaculture practices within the region, decided on the basis of consultations among the concerned state agencies. Suitable mechanisms, such as the exchange of data bases and the establishment of information networks, have to be developed to collect, share and disseminate relevant information relating to aquaculture and aquaculture-based fisheries, in order to facilitate cooperation in the planning of development at national, regional and global
levels. Efforts should be made to conserve genetic diversity and maintain the integrity of aquatic systems. There are well-developed systems to minimize disease outbreaks and detrimental effects caused by escaped fish from farms and enhanced stocks. The states should consider the licensing of farming enterprises based on environmental impact assessments.
Licenses should include the precondition of monitoring the mitigatory measures to be provided if found necessary on impact assessment studies. These may cover water usage and waste disposal such as settling tanks, restrictions on the use of mangrove swamps for the location of farms, and polyculture with bivalves and weeds that make productive use of particulate and dissolved wastes (FAO/NACA, 1996). Since most of the wastes in fish culture farms are produced by feed sediments and feed spillage, feed manufacturers should be encouraged to improve the water-stability of feeds and the feed quality by reducing proteins and increasing lipid contents, so as to decrease the emission of nitrogen and phosphorus to the farm environment. Processing of feed by extrusion methods, though expensive, may result in the production of eco-friendly feed. Because of the need for reducing the fishmeal content of the feeds, the replacement of proteins and lipids should be promoted. In recognition of the potential of aquaculture to contribute to the world food supply, national, regional and international authorities should give high priority to the transfer, adaptation and development of technological innovations and capacity-building to stimulate aquaculture practices and establish economical culture-based fisheries.