Resource Use and Pollution Potential in Feed-Based Aquaculture
Claude E. Boyd, Aaron A. McNevin
Abstract
Feed use in aquaculture results in large amounts of embodied land, freshwater, energy and wild fish use. Selection of feed ingredients at feed mills can reduce the amounts of one or more of the four major natural resources embodied in feed. However, better feed management to lessen FCR is more likely the key to lessening resource use at the farm level. Of course, lessening the FCR will reduce the amount of feed that must be purchased and diminish the direct and embodied negative environmental impacts associated with feed. It also is important to note that mechanical aeration applied in many methods of production requires more energy than associated with feed alone. Aeration is necessary for high feed inputs required in intensive production, and without aeration, most types of intensive production would not be possible. The amounts of resource use attributed to feeding and aeration were applied in estimating the resulting quantities of water pollutants in effluents and emission of atmospheric contaminants. Some of the misunderstandings about life cycle assessment (LCA) such as it usually covering all impacts of product systems, and especially its failure to assess the oxygen demand of effluents are mentioned.