Mortality of Juvenile Sablefish Captured by Hand-Jigging and Traps

Abstract

Capturing juvenile sablefish Anoplopoma fimbria with hand-jigs instead of traps and when water temperatures are relatively warm (late spring to autumn in southeastern Alaska) reduces tagging mortality. After 1 week in holding tanks, mortality of hand-jigged sablefish was 19%, whereas mortality of fish caught by traps was 75%. Myxobacteriosis may have contributed to mortality. This disease was initiated by handling stress and mechanical injury; its signs included grey, saddle-shaped lesions, hemorrhaging of the ventral abdomen and fins, and caudal fin erosion. Greater survival of hookcaught juvenile sablefish in summer than in winter may have been due to less favorable conditions for the bacteria during warmer water temperatures.