ASSESSING THE ENVIRONMENTAL IMPACT OF TROUT AQUACULTURE ON THE LEBANON PORTION OF THE ASSI (ORONTES) RIVER

Trout aquaculture using river water invariably releases metabolites and organic particulates and various other chemicals into the water stream. Accordingly, maximum contaminant levels (MLC) allowed are reached depending on the flow of the river, the quality of the incoming water and the quantity of aquaculture production on the river. Various countries regulate natural body water quality using various methods but all require a census of aquaculture production on the river. In Lebanon, trout aquaculture is concentrated on the Orontes River but no study exists that evaluates contaminant input into the waters or the effects of aquaculture on water quality. The present study was performed to evaluate water quality, effects of aquaculture on the environmental status of the river and the possibility of increasing trout production or the necessity to decrease it. Every aquaculturist or fish farm owner along the river was interviewed and water quality at various locations along the river was also tested periodically. Topics studied were various raceway design and construction methods, fish feed quality and feeding practices, water quality of the river itself, various governmental regulations relating to riverine systems or to aquaculture, and finally we used the results to calculate and assess environmental impacts of aquaculture on the river. Results suggest that trout aquaculture along the Lebanese portion of the Assi River does not pollute the river. However, there are other contamination sources, mainly municipal effluents that have an effect on the river, especially during the summer when river flow decreases. Proper management and policing by local authorities could allow for a big increase in aquaculture production without adverse impacts on the river. We consider our most important finding to be that education of all aquaculturists is necessary to improve farm management protocols in order to ensure growth of the industry while maintaining sustainability of the environment. We would suggest that the government should employ a full time extension agent to serve the industry.