Acoustic observations of nekton and zooplankton along the Northeast continental shelf break

Abstract

Observations of fish and squid (nekton) and crustacean and gelatinous animals (zooplankton) at the shelf break using active acoustic systems (e.g., echosounders) have been made along the United States shelf break from the mid-Atlantic to New England since the early 2000s as part of a biennial bottom trawl survey (NOAA’s Northeast Fisheries Science Center), since 2012 as part of the Atlantic Marine Assessment Program for Protected Species (AMAPPS), and recently as part of the Task Force Ocean New England Shelf Break Acoustic project. The shelf break can be a boundary between seabed-oriented species on the continental shelf and pelagic species in the open ocean, as well as transitional habitat for some species to exploit. These data have been collected using multifrequency, narrowband (e.g., 18, 38, 70, 120, and 200 kHz) and wideband (18–250 kHz) scientific echosounders with hull-mounted transducers to primarily map the prey species of mid- to upper-trophic level foragers and predators. Classification of acoustic data to biologically meaningful metrics and how these can be integrated with oceanographic features and spatial and temporal distributions of predators will be explored in relation to the broader goals of developing ocean acoustic networks. [Work supported by the Office of Naval Research.]