Technical Abstract: Alaska’s fishing industry generates over one million metric tons of fish by-products each year, much of which is discarded during processing unless fishmeal plants are located nearby. Preservation methods, such as acidification, are less commonly used to inhibit spoilage. In this study, individual salmon by-products (heads, viscera, and a mixture) were stabilized through fermentation by lactic acid bacteria and through ensilage by direct acidification. Viscera and heads preserved separately for 120 days maintained a lower, more desirable pH than when mixed together. This finding has major implications for how fish processing waste should be collected and stored if maximum nutritional quality is to be preserved.