Lumpfish (Cyclopterus lumpus) used as cleaner fish: Characterization and suitability for human consumption

Farmed lumpfish (Cyclopterus lumpus) is frequently used as cleaner fish in Norwegian salmon aquaculture. During the period in the net cage, the lumpfish feed on salmon lice. After a time, the fish stop eating the lice and are then withdrawn from the net cage without further exploitation. In this study, the nutritional value of lumpfish was characterized to assess its suitability as a human food. The lumpfish were collected from two separate salmon aquaculture facilities and analyzed for proximate composition, amino acids, fatty acids, vitamins, minerals, environmental pollutants, and heavy metals. The water and protein content were approximately 90 and 6%, respectively. The protein contained all essential amino acids. The fat content ranged from 0.9 to 3.7% with a high level of the long chain polyunsaturated fatty acids EPA (eicosapentaenoic acid; 20:5n-3) and DHA (docosahexaenoic acid; 22:6n-3). Lumpfish may be a good source of B12 and D3 vitamins, however, the content of several minerals was low. The environmental pollutants and heavy metals were below the EU maximum levels, making the lumpfish safe for human consumption. Overall, our results indicate a potential to exploit the lumpfish, even after its time as a cleaner fish.