Controlled flow, temperature and brook trout (Salvelinus fontinalis Mitchell) fry emergence on the Aguasabon River, Terrace Bay, Ontario, 2011-2016

Abstract

This thesis reviews factors that affect brook trout (Salvelinus fontinalis Mitchell) fry emergence and their relevance to population fitness. A series of drift nets were deployed from 2010 to 2016, April through May, on the Aguasabon River, near Terrace Bay, Ontario, to capture brook trout fry drifting downstream. Fry were live captured, counted and released alive each year. The drift nets recorded flow, and nearby data loggers recorded temperature of the redd. Graphical review of these data was used to determine any significant relationships between brook trout drift, net flow and temperature. Flow does not affect temperature, but brook trout fry respond numerically to an optimal temperature, and high flows encourage drifting. These relationships are described relative to management of an impounded brook trout spawning stream.