Fall and Winter Brook Trout Prey Selection and Daily Ration

Most studies examining salmonid diets and their relationship to invertebrate drift are confined to periods from spring through early fall. Invertebrate drift generally decreases from spring through summer and fall seasons and is greatest during diel periods of low light. Salmonid feeding efficiency is reduced under low light conditions and several studies have found them to feed primarily through the daylight hours. Drift feeding salmonids are also size selective. The purpose of this study was to determine if patterns of invertebrate drift and brook trout feeding seen during warmer times of the year hold during the post-spawning fall and winter for brook trout (Salvelinus fontinalis) in the central Appalachians. The general diel pattern of invertebrate drift and salmonid feeding found during spring and summer months in other studies was less obvious during the post-spawning fall and winter for brook trout. Total invertebrate drift density did not follow a diel pattern. Brook trout diet composition was not correlated to the composition of invertebrate drift and brook trout may feed from the benthos more frequently than previously suspected for stream salmonids. There appeared to be no diel effect on brook trout feeding. Brook trout daily ration during the fall and winter were extremely low and may have been below maintenance ration during the fall.

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