Translocating southern rock lobsters (Jasus edwardsii) from deep-water to shallow inshore water enhances nutritional condition through omega-3 long-chain polyunsaturated fatty acid content

Deep-water southern rock lobsters (Jasus edwardsii) were translocated into shallow-water inshore reefs around Tasmania in an attempt to enhance their growth rates and market traits. We assessed changes in nutritional condition in adult, deep-water lobsters before and 12 months after relocation through variations in the lipid and fatty acid profiles in the hepatopancreas and muscle. Fatty acid compositions were similar between shallow and translocated lobsters and both were different from deep-water lobsters, suggesting a dietary difference between the deep and shallow-water lobsters, and a dietary change in deep-water lobsters after translocation. Nutritional condition indices, such as total lipid and triacylglycerol content, did not significantly vary between the lobster populations which may be due to within-population variability driven partly by differences in the moult stage of lobsters. Mean concentrations of fatty acids, lipid content and essential polyunsaturated fatty acids (PUFA) were higher in translocated lobsters than in both deep and shallow-water lobsters. Mean omega-3 long-chain PUFA content, in particular eicosapentaenoic acid (EPA, 20:5n-3) increased by 30% in the muscle of translocated lobsters, resulting in an enhanced nutritional value and a change in overall body condition. This enhancement of key fatty acids, achieved through translocation, highlights the market potential of translocation for the commercial industry.