Effects of Salinity on the Oxygen Consumption Rate of Juvenile Lumpfish (Cyclopterus lumpus) in the Laboratory

The lumpfish (Cyclopterus lumpus) is a commercially important species in Iceland and the Netherlands, where it is fished for roe which is used for caviar. Moreover, several recent studies have shown that lumpfish juveniles are useful ‘cleaner fish’ in the Atlantic Salmon aquaculture industry. In this practice, juveniles are placed in pens with salmon to feed on the sea lice that infect salmon. Despite the importance of the species, little is known about its ecology. This study is examining how one environmental variable (salinity) impacts the oxygen consumption of juvenile lumpfish.  To determine this, juveniles were exposed to five salinity treatments (10, 15, 20, 25, 20 ppt) and oxygen consumption rates were measured. Standard metabolic rates (SMR) were calculated using SMR = aVM, where a is the slope (dissolved oxygen/time), V is the volume of the chamber, and M is the mass of the fish. Preliminary results showed that juveniles could tolerate salinities down to 10 ppt for short periods of time. Complete results will provide a better understanding of juvenile lumpfish habitat and physiological ecology. This information will help inform the management of coastal and fishery resources, as well as those who wish to use lumpfish in aquaculture operations.