Effect of salinity at constant 10 °C on grow-out of anadromous Arctic charr from Labrador

The goal is to determine the requirements allowing cultured Salvelinus alpinus to thrive in seawater, as they do in the wild. In late-June, eight families of individually identified 1+ year-old charr (mean wt: 427 g) of a domesticated strain derived from the Fraser River population were directly transferred from freshwater (9 °C) to salinities of either 0, 10, 20 and 30 ppt at 10 °C, then on-grown in tanks until December. Cumulative mortality was 16% in 30 ppt salinity, and 1.7 in 0 and 10 ppt. In 20 ppt salinity, growth was initially similar to that in ≤10 ppt salinity but deteriorated from September onwards. Sexually maturing fish in ≤10 ppt salinity attained a final mean weight about 35% less than immatures. Plasma osmolality was only slightly elevated in the 30 ppt salinity, remaining