Impacts of Fish Introduction on Aquatic Environment: a Study with Special Reference to Common Carp/ Cyprinus Carpio, (Linnaeus, 1758)

Abstract

Fish introduction was practiced for years in the world for economical, social, biological and ecological purposes without consideration of the deleterious impacts on the aquatic environment. The most important environmental impacts caused by fish introduction were competition for resources, predation, disease and parasites, genetic impacts, fish community alternation, physiological changes, impact on other aquatic fauna, habitat alternation and socioeconomic impacts. The impacts of fish introduction were evaluated on the following criteria: species suited to the physico-chemical properties of the intended water body; attractiveness and profitability of the fish to the fishers; fish with good flesh quality for the consumers; and fish that fill a vacant niche to establish balanced community. Fish introduction in Ethiopia started during the Italian invasion and then the practice expanded in many natural and man-made waters. Information on management, status and impact on the aquatic environment were not well documented. The literature review, focus group discussion and field observation indicated that ill-conceived and poorly monitored fish introduction was practiced. As the rule of thumb, well-organized and adequate knowledge on fish introduction management is essential in ‘Resource Management Challenged Environments’ and for ‘Meeting the needs of the society, and keeping the balance of aquatic environment.