Reduction of Waste Output from Salmonid Aquaculture through Feeds and Feeding

The main goal of aquaculture is to efficiently convert feed into fish and shellfish. Inherent to this practice is the generation of waste; however, from a waste management viewpoint, aquaculture differs in important respects from terrestrial animal farming. Measurement of actual feed intake is nearly impossible; consequently, unconsumed feed contributes a relatively large proportion of total waste output in most operations. Moreover, containment of wastes is difficult, and wastes are rapidly dispersed into the surrounding waters. Monitoring and estimating quantitative waste outputs in effluent directly is an inaccurate and costly process. Other methods of estimating the waste output from aquaculture operations should be used. Because most aquaculture wastes are dietary in origin, efforts to reduce waste should focus on nutrition and feeding, including the formulation of special diets, development of feeding systems, and improvement of the efficiency of nutrient utilization. Modern low-pollution o...