ABSTRACT
Water pollution from aquaculture is currently under considerable scrutiny from governmental environmental authorities. Flowing water aquaculture effluents contain solid waste, dissolved solids, fertilizer nutrients, and BOD (biochemical oxygen demand) that may harm sensitive receiving waters, such as trout streams. Fish production at some facilities is effluent driven, meaning that carrying capacity is determined by the levels of pollutants discharged to the receiving waters. Effluent treatment to reduce total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP) appropriately to flow through trout aquaculture involves (1) improved farm management and (2) effluent treatment. Farm management strategies to improve effluent water quality include the provision of the best possible rearing conditions to avoid stress and nutrient excretion. Keeping dissolved oxygen (DO) levels above 100 mm Hg and maintaining high fish densities have been shown to reduce nutrient loads in trout hatchery effluents (Sindilariu 2007).
