SUSTAINABLE AQUACULTURE

Grishma Tewari and Akansha Bisht

Department of Fishery Biology, College of Fisheries,

G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India

Aquaculture is currently one of the fastest growing food production systems in the world. Most of the global aquaculture output is produced in developing countries and significantly in low-income food-deficit countries. As defined by the united food nations Food and Agriculture Organization (FAO), aquaculture is the "farming of aquatic organisms including fish, mollusks, crustaceans and aquatic plants. With stagnating yields from many capture fisheries and increasing demand for fish and fishery products, expectations for aquaculture to increase its contribution to the world's production of aquatic food are very high, and there is also hope that aquaculture will continue to strengthen its role in contributing to food security and poverty alleviation in many developing countries. However, it is also recognized that aquaculture encompasses a very wide range of different aquatic farming practices with regard to species (including seaweeds, molluscs, crustaceans, fish and other aquatic species groups), environments and systems utilized, with very distinct resource use patterns involved, offering a wide range of options for diversification of avenues for enhanced food production and income generation in many rural and peri-urban areas.

What is sustainable development?

Though living resources are self-renewable, they have to be utilized rationally on a sustainable basis in harmony with the environment. Sustainable development is the management and conservation of the natural resource base and the orientation of technological and institutional change in such a manner as to ensure the attainment and continued satisfaction of human needs for present and future generations. Such sustainable development (in the agriculture, forestry and fisheries sectors) conserves land, water, plant and animal genetic resources and it is environmentally non-degrading, technically appropriate, economically viable and socially acceptable.

Need for Sustainable development:

Aquaculture now accounts for roughly one third of the world's total supply of food fish and undoubtedly the contribution of aquaculture to sea food supplies will increase in the future. Aquaculture has potential to become a sustainable practice that can supplement capture fisheries and significantly contribute to feeding the world's growing population. Aquaculture is the fastest growing sector of the world food economy, increasing by more than 10% per year and currently accounts for more than 30% of all fish consumed.

Aquaculture, in common with all other food production practices, is facing challenges for sustainable development. Most aqua-farmers, like their terrestrial counterparts, are continuously pursuing ways and means of improving their production practices, to make them more efficient and cost-effective. Awareness of potential environmental problems has increased significantly. Efforts are under way to further improve human capacity, resource use and environmental management in aquaculture. COFI emphasized enhancement of inland fish production through integrated aquaculture-agriculture farming systems and integrated utilization of small and medium-size water bodies

Unsustainable aquaculture will only generate short and medium term profits for multinational corporations at the expense of long-term ecological balance and social stability. An unsustainable aquaculture development could exacerbate the problems and create new ones, damaging our important and already stressed coastal areas. Sustainable development alternatives are needed to ensure that in the future aquaculture can contribute to the growing need for seafood products. The sustainable development includes- "the management and conservation of natural resource base, and the orientation of technological and institutional change in such a manner to ensure the attainment and continued satisfaction for present and future generations. Such developments conserve land, water, plant and genetic resources as well they are environmentally non-degrading, technologically appropriate, economically viable and socially acceptable.

The promotion of sustainable aquaculture development requires that "enabling environments", in particular those aimed at ensuring continuing human resource development and capacity building, are created and maintained. The FAO Code of Conduct for Responsible Fisheries contains principles and provisions in support of sustainable aquaculture development. The Code recognizes the Special Requirements of Developing Countries, and its Article 5 addresses in particular these needs, especially in the areas of financial and technical assistance, technology transfer, training and scientific cooperation.

There are a number of alternatives for sustainable development of aquaculture which include ecological aquaculture, organic aquaculture, composite fish culture, integrated aquaculture and closed recirculatory systems.

Ecological Aquaculture

Ecological aquaculture has been defined as- "an alternative model of aquaculture research and development that brings the technical aspects of ecological principles and ecosystem thinking to aquaculture and concerns for the wider social, economic and environmental context of aquaculture".

There are few main principles of aquaculture:

• To preserve the form and function of natural resources

• To ensure trophic level efficiency

• To use native species so as not to contribute to biological pollution

• To share the practices and information on a global scale

• To ensure that system is integrated into the local economy and community in terms of food production and employment

Ecological aquaculture focuses on the development of farming systems that protect the environments in which they are situated and enhances the quality of these environments while at the same time maintaining a productive culture system.

Organic Aquaculture

Sustainability is one of the main goals of organic food production. Some of the basic principles of organic aquaculture according to the International Federation of Organic Agriculture Movements are as follows-

• To encourage natural biological cycles in the production of aquatic organisms

• Using various methods of disease control

• No use of synthetic fertilizer or other chemicals in production

• Use of polyculture technologies whenever possible

Polyculture and Integrated Aquaculture

Polyculture and integrated aquaculture are methods of raising diverse organisms within the same farming systems, where each species utilizes a distinct niche and distinct resources within the farming complex. This may involve the rearing of several aquatic organisms together or in conjunction with terrestrial plants or animals.

Polyculture system can provide mutual benefits to the organisms reared by allowing for a balanced use of the available aquatic resources while integrated systems can increase the economic efficiency through improved conversion rates of input materials. The waste from one organism is used as input to another resulting in the optimal use of resources and less pollution overall. Although still experimental, other systems such as- integration of sea weed, fish and abalone culture and polyculture of shrimp and tilapia, have proved to be ecologically efficient methods for growing a variety of organisms and may increase profit at fish farms.

Recirculating system

Concerns for water conservation and reduced waste discharges have realized the use of closed recirculating aquaculture systems. This system is made up of three basic components: culture chamber, settling chamber and biological filter. Water enters the culture chamber, flows through the settling chamber and then moves through the biological filter to remove additional particulate matter. The water is then circulated back through the system culture chamber.

Recirculating systems conserve water and allow control of environmental factors (temperature, salinity and oxygen), predators and introduction and transfer of diseases. This system has less impact on environment because of their close nature - wastes and uneaten feed are not simply released in the ambient environment. In recirculating system, wastes are filtered out of the culture system and disposed of in a responsible manner.

In order for aquaculture to develop into an environmentally and socially responsible food production endeavor, following points should be recommended-

• Implement more ecologically sustainable practices

• Transition to use of closed systems and low discharge systems, especially those that provide total containment of fish and recovery or reuse of wastes

• Significantly decrease or eliminate the dependence on wild fisheries

• Develop sustainable aquaculture operations that provide long term social and economic benefits to communities

REFERENCES:

Mehta, Varun (2006). Fisheries and Aquaculture Biotechnology. Campus books international public., pp. 214.

Bardach, John E. (1997). Sustainable Aquaculture. John Wiley and Sons public.

Pillay, T. V. R. and Kutty, M. N. (2005). Aquaculture: Principles and Practices. Wiley-Blackwell public.

Pillay, T. V. R. (2004). Aquaculture and the environment. John Wiley and Sons public.

Barg, U. C. (1992). Guidelines for the promotion of environmental management of coastal aquaculture development. Food & Agriculture Org. public.