Predation on Atlantic Salmon Smolts by Striped Bass after Dam Passage

Abstract

We documented predation on smolts of Atlantic salmon Salmo salar by striped bass Morone saxatilis foraging in the tailrace of the Essex Dam on the Merrimack River, Lawrence, Massachusetts, and assessed factors that may affect smolt susceptibility to predation. During 6 d of diurnal angling from 6 to 28 May, we captured 212 striped bass, 41 of which contained prey remains. More than 48% of striped bass that contained prey had consumed smolts. Atlantic salmon smolts composed more than 80% of the total mass of prey remains recovered and included both individuals of stocked-fry and stocked-smolt origin. Based on information from this pilot study, a focused investigation of striped bass predation on smolts after passage of the Essex Dam began in 1998.