SISP 11 - Manual for the International Deep Pelagic Ecosystem Survey in the Irminger Sea and Adjacent Waters. Version 1.0

Abstract

The Working Group on Deep Pelagic Ecosystem Surveys (WGIDEEPS), formerly known as Working Group on Redfish Surveys (WGRS) and Planning Group on Redfish Surveys (PGRS), has the responsibility of coordinating international trawl-acoustic surveys on pelagic beaked redfish (Sebastes mentella) in the Irminger Sea and adjacent waters and in the Norwegian Sea. Surveys on pelagic beaked redfish (Sebastes mentella) have been conducted since 1982 in the Irminger Sea and since 2007 in the Norwegian Sea (ICES, 2009b; 2013). These surveys have been conducted by individual nations or in collaboration between two or more nations. The area coverage and methodology however, have varied and often the area coverage was limited, especially in earlier years. The surveys are mainly hydroacoustic surveys, but since 1999, pelagic trawling has also been used to estimate biomass of pelagic beaked redfish when acoustic estimates are not possible. Over time, both the horizontal and vertical coverage have increased, as earlier surveys were not considered sufficient for stock assessment purposes (ICES, 2013). Furthermore, the survey has also moved from exclusively a redfish survey to an ecosystem survey. This manual seeks to describe the survey conducted in the Irminger Sea and adjacent waters and its history, paying particular attention to the current practices in place (gears, area coverage, sampling methods). Description of acoustic equipment and trawl gears, areas covered, sampling methods, and data collected are described in detail.