DEVELOPING AQUACULTURE IN DEGRADED INLAND AREAS IN NIGERIA

BACKGROUND TO THE STUDY: Nigeria, the country of many rivers, is also rich in lakes, reservoirs and wetlands but many of them had been degraded due to a lot of factors (FGN, 1993). Sustainable fisheries production and development depends largely upon good aquatic environment. It is generally accepted that the future well-being of a developing country such as Nigeria, will depend upon a much wiser balance between exploitation and conservation of natural resources in order to achieve sustainable systems that would avoid environmental degradation (Butt, 1985).

The quality of the aquatic medium determines success to a very large extent in fisheries and aquaculture. Paulin (1989) noted that "the aquatic medium is in direct and immediate contact with the metabolic processes of fish". Relevant soil structure and composition and natural environmental factors (e.g. pH, dissolved oxygen concentration, temperature, salinity) all influence the quality of the medium, which is turn determines the health of the fish and their performance. For quite some time now, Nigerian freshwater ecosystems are being damaged and degraded at accelerating rates by toxic contamination from industrial and urban pollution, infectious diseases, dam construction, irrigation, factory farming, forest and wetland destruction. Consequently, there has been a steady increase in the quality and diversity of discharges that reach our freshwater environment (Anko & Eyo, 2001).

Without question, the lack of available quality inland areas has emerged as the greatest threat to sustainable fisheries and aquaculture. Freshwater must be a national commons. Most human beings in developing countries like Nigeria view freshwater as a universal heritage of society. Our common societal heritage of freshwater demands ecological maturation in the use of these finite resources. According to Ita (1993), in every regard to national health, agriculture and economics, the continued over exploitation and misuse of finite freshwater resources is directly causal to the progressively deteriorating fish production and general standard of living. We must recognize that fisheries and aquaculture development depends on maintaining satisfactory water quality.

The integration of basic understanding of the inland water systems with applied problems and their solutions should be of concern to all stakeholders in our freshwater resources. The study highlights the importance of quality inland area in Nigeria for fisheries including aquaculture and examines the various sources of degradation their impacts and possible control measures for effective development of aquaculture.

1.2   STATEMENT OF THE PROBLEM

Degradation of inland waters in Nigeria occurs in both rural and urban areas. In the rural areas inland waters such as rivers, streams and lakes are usually polluted by inorganic substances used in agricultural activities usually pollute streams and lakes. Such substances include fertilizers pesticides and herbicides. These substances applied on farmlands are sometimes washed down by rain into stagnant ponds and pools of water on the plain and also into storage reservoirs.

Excessive load of fertilizers (nutrients) in the water, generate, excessive growth of phytoplankton, which in turn can lead to high biological oxygen demand, thus resulting in aquatic degradation as a result of drastic oxygen depletion of the water, causing much stress to the great majority of fish species, which gradually die off. Many factories in Nigeria are located on riverbanks and use the rivers as open sewers for their effluent. Improper disposal of untreated industrial wastes has resulted in -coloured, murky, odorous and unwholesome fresh waters, fish-kills and a loss of water quality. The major industries responsible for water pollution in Nigeria include petroleum, mining (for gold, tin and coal), wood and pulp, pharmaceuticals, textiles, plastics, iron and steel, brewing, distillery fermentation, paint, beverages and food. However, this study is examining how aquaculture can be developed even with these degradations in Nigeria.