Adding value to ragworms (Hediste diversicolor) through the bioremediation of a super-intensive marine fish farm
The treatment of organic-rich effluents often represents an economic burden to marine and brackish water fish farms. The ragworm Hediste diversicolor, an euryhaline polychaete, displays a remarkable trophic plasticity and can readily be used in sand filters to bioremediate the load in particulate organic matter (POM) present in such effluents. These organisms selectively retain in their tissues valuable nutrients that would otherwise be lost to the environment, namely an important polyunsaturated fatty acid (PUFA) for marine fish and shrimp nutrition – docosahexaenoic acid (DHA, 22:6n-3). Ragworms cultured using these effluents display an enhanced nutritional value, when compared to conspecifics collected from the wild, and thus may easily commend premium market prices if traded for maturation diets for fish and/or shrimp broodstock.