Swimming Depth of Adult American Eels (Anguilla rostrata) in a Saltwater Bay as Determined by Ultrasonic Tracking

Abstract

Pressure-sensing ultrasonic transmitters in the gut were used to determine the swimming depth of five American eels (Anguilla rostrata) in Passamaquoddy Bay, New Brunswick, in autumn. The eels made frequent dives from surface to bottom, in places diving at least 45 m deep, at vertical speeds to 76 cm/s. About one quarter of the time was spent near the surface; very little time was spent near the bottom or at any constant intermediate depth range.