Aquaculture

There is now little doubt that our world's fisheries are in crisis. Mounting specific evidence points to dramatic declines in global catches. Increasingly, many are making the case that Fish farming offers a solution to meet the growing demand for seafood that catching fish can't provide.




"AQUACULTURE is the farming of aquatic organisms including fish, molluscs, crustaceans, and aquatic plants. Farming implies some sort of intervention in the rearing process to enhance production, such as regular stocking, feeding, protection from predators, etc. Farming also implies individual or corporate ownership of the stock being cultivated."


HISTORICAL OVERVIEW

It was not until after World War II that aquaculture gained much attention as a potentially large scale industry. A shift in economic conditions in developed nations of the world led to an increase in the demand for fish such as salmon, shrimp, eels, and sea bases, all of which can be produced profitably through aquaculture. In the 1960s, aquaculture became a significant commercial practice in Asia where it had mainly been used as a small-scale means of local community food production for thousands of years. In the last few decades, worldwide aquaculture production has increased significantly. In 1970, aquaculture operations composed 3.9% of all fish production, compared to 27.3% in 2000. Worldwide, total fish production from aquaculture operations has increased steadily at a rate of 9.2% per year. But, aquaculture has not yet become the large-scale global food replacement for the numerous food-poor areas of the world, as many thought it would be.


SUSTAINABLE ALTERNATIVES

There are number of alternative ways forward in the development of aquaculture, which can offer more sustainable solutions. Alternatives includes Ecological Aquaculture, Organic aquaculture, Polyculture, Mollusc Farming. These alternatives have been successfully implemented in different areas of the world; however, they must be examined for their application on a wider scale.

• 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 ecosystems thinking to aquaculture, and incorporates - at the outset - principles of natural and social ecology, planning for community development, and concerns for the wider social, economic, and environmental contexts of aquaculture.

There are six main principles of ecological aquaculture :-

1. To preserve the form and function of the natural resources.
2. To ensure trophic level efficiency (using animal wastes and plants, rather than fishmeal as sustenance).
3. To ensure that chemicals and nutrients from the system are not discharged as pollutants.
4. To use native species so as not to contribute to "biological pollution".
5. To ensure that the system is integrated into the local economy and community in terms of food production and employment.
6. To share the practices and information on a global scale.

Ecological aquaculture focuses on the development of farming systems that preserve the environments in which they are situated and enhances the quality of these environments while at the same time maintaining a productive culture system. All aspects of the operation are interconnected in order to minimize negative impacts on the community, both natural and social.

• Organic Aquaculture

An alternative model of aquaculture whose main goal is of organic food production and to manage food production as an integrated, whole system that is an 'organism' whose individual parts mesh together into one whole production is called Organic aquaculture. In organic food production, all parts of the operations are connected and integrated with each other, such as nutrient inputs, the animals, the environment, and the wastes being produced.

Some of the basic principles of organic aquaculture according to the International Federation of Organic Agriculture Movements are as follows :-

1. To encourage natural biological cycles in the production of aquatic organisms.
2. Using feed that is not intended or appropriate for human consumption.
3. Using various methods of disease control.
4. Not using synthetic fertilizer or other chemicals in production.
5. Using polyculture techniques whenever possible.

Organic aquaculture standards have been developed in many nations around the world and they are in the final stages of development in the United States. But, there are several obstacles to the implementation of organic aquaculture, including: farming carnivorous fish with a diet of wild (non-organic) fish, management and recycling of wastes, escapes of fish, and controlling diseases and parasites.

• Polyculture

Polyculture is the method of raising diverse organisms within the same farming system, 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 it could involve raising aquatic organisms in conjunction with terrestrial plants and animals. In case, the wastes from one organism are used as inputs to another, resulting in the optimal use of resources and less pollution overall.

Polyculture systems can provide mutual benefits to the organisms reared by creating symbiotic relationships while allowing for a balanced use of the available aquatic resources, whereas intensive monoculture systems extract resources from the system and place more stress on the surrounding environment. In addition, Polyculture system can increase the economic efficiency of Fish farms through improved conversion rates of input materials.

• Mollusc Farming

While not a new activity, mollusc farming offers an excellent alternative to finfish farming. With proper sitting and planning, mollusc farms can have minimal impact upon coastal ecosystems and communities. In some cases the presence of mollusc farms can actually improve the water quality of the existing environment. Oysters, mussels, clams, and scallops are some typically farmed mollusc species.

In most cases mollusc farming does not have the same impacts upon the environment that finfish culture does, such as nutrient loading and eutrophication. Unlike other farmed species, shellfish remove organic particulates, suspended matter, and nutrients from the water and tend to improve the overall quality of the water. Because shellfish are filter feeders, they act as natural biofilters in the water, removing phytoplankton, sediments, and organic particles.

While relatively benign when properly planned and managed, in some instances, mollusc farming has been responsible for the introduction of non-native species and diseases as well as conflicts with other user groups.


MAKING IMPROVEMENTS

Recntly, governments and industry have made efforts to curb unsustainable aquaculture must evolve into the development of an industry that is both environmentally and socially sustainable in the long term. Positive changes are being made with this growing interest and awareness of improving the sustainability of aquaculture. With the expected expansion of aquaculture in the coming years it will be vital that sustainable practices be implemented and further developed to avoid environmental and social problems.