Comparison of growth and survival of sea-run and landlocked strains of Atlantic salmon Salmo salar in the Lake Ontario watershed

In managing Atlantic salmon Salmo salar, New York fisheries agencies have historically stocked both landlocked and sea-run strains. The objective of this study was to compare young-of-year survival and growth among a variety of strains in both the laboratory and in streams. Atlantic salmon fry of four strains (sea-run: Merrimack River and Penobscot River; landlocked: West Grand Lake and Lake Memphremagog) were stocked for four years in five central New York streams. Laboratory experiments compared growth rates at six temperatures (12, 15, 18, 20, 23, and 25 °C) experienced in New York streams during the summer. Comparisons among monthly survival and specific growth rates at all stream sites and years resulted in no obvious trends; survival ranged from 0 to 81% and growth rates were between 0.02 and 0.04 g·g− 1·d− 1. There were no significant differences in growth or survival observed between sea-run versus landlocked strains. Within the five study streams, the Lake Memphremagog strain had the highest growth rates, while growth rates were similar in the laboratory between Lake Memphremagog and Merrimack River strains. Based on laboratory and field assessments, Atlantic salmon specific growth rate was greatest at approximately 18 °C during the summer months. Future research in Lake Ontario should include further assessment of the Lake Memphremagog strain, especially on direct tributaries with access for returning adults, as well as continuing to establish a Lake Ontario specific strain.