Production and Growth Efficiency of Brook Trout (Salvelinus fontinalis) in Two Adirondack Mountain (New York) Lakes Following Liming

Abstract

Yearling and spring fingerling brook trout (Salvelinus fontinalis) stocked in two Adirondack lakes after liming in the spring of 1985 produced 10-14 kg .cntdot. ha-1 yr-1 at average standing crops of 8-10 kg .cntdot. ha-1 during the first year after stocking. These values were similar to levels observed in other limed and circumneutral Adirondack lakes, which collectively support a limited range of biomass (10-20 kg .cntdot. ha-1) and production (7-16 kg .cntdot. ha-1) compared with more fertile waters in other regions. The estimated level of food consumption required to maintain initial production rates observed in the two lakes was 80-100 kg .cntdot. ha-1. This level of predation was sufficient to significantly after the size structure and composition of the invertebrate prey community within a few months after stocking. However, mean production efficiency in these populations remained at levels of 20-25% and the development of adverse water quality conditions in the first year after liming appeared to be of greater significance than food limitation in regulating production and biomass of these stocked brook trout populations. Reacidification of one lake 5 mo after liming resulted in rapid declines in biomass and production as a result of both increased mortality and reduced growth.