Growth performance of fish in any production system is affected by environment and genetics. The St. John River (SJR) strain of Atlantic salmon Salmo salar has been selected for growth in net pens at the National Cold Water Marine Aquaculture Center (NCWMAC), Franklin, ME for five generations while the Gaspe strain was previously selected for growth in tanks for two generations. It was previously shown the Gaspe strain outperformed the SJR strain in a recirculating aquaculture system (RAS). With RAS Atlantic salmon facilities coming to the U.S., we sought to investigate whether the selected SJR strain would perform as well or better than the Gaspe strain across a range of RAS environments. Approximately 1,000 eyed eggs (2,000 eggs total) from both strains were shipped separately to The Conservation Fund’s Freshwater Institute (TCFFI; Shepherdstown, WV) and an additional 2,000 eggs the Northern Aquaculture Demonstration Facility (NADF; Bayfield, WI). Eyed eggs were also maintained and grown at the NCWMAC. All studies were conducted under experimental RAS conditions. Once the fish reached ~50 g/fish, they were pit tagged, weighed, and combined into tanks at each location until they reached approximately 4 kg/fish.
Results from FCFFI showed the SJR strain weighed 4.6 kg/fish while the Gaspe strain weighed 3.6 kg/fish at harvest. Similarly, at the NAD, the SJR strain weighed 4.8 kg/fish while the Gaspe strain weighed 2.6 kg/fish. SJR strain fish at the NCWMAC weighed 2.7 kg/fish while the Gaspe strain fish weighed 1.8 kg/fish at the most recent sampling. A complete profile of growth, fillet characteristics, mortality, and maturity will be presented. The results of the study clearly show the growth superiority of the SJR strain when compared to the Gaspe strain when reared in RAS.