Internationally coordinated deep-water surveys can be a source of abundance indices for species such as roundnose grenadier, black scabbardfish, deep-water sharks, Greenland halibut, beaked redfish, bluemouth redfish, greater silver smelt and greater forkbeard, and also be a platform for carrying out studies of deep-sea communities.
The first meeting as a working group was in 2010 as a follow up to the Planning Group on the North-east Atlantic Continental Slope Survey (PGNEACS). In order to reassess survey needs, the group has reviewed the main deep-water fish resources in the Northeast Atlantic, summarized their spatial extent and exploitation patterns and identified the necessary survey attributes to produce advice on single-stocks of commercial species, non-target species and advice on the effect of fishing on the deep-water ecosystem.
The group has also reviewed how existing survey programmes meet the requirements and where there are important gaps in terms of stock and area coverage. This analysis revealed three subgroups of existing deep-water surveys and new survey requirements (proposals) that are grouped by geographical area.
The first subgroup deals with Nordic deep-water trawl surveys that are currently undertaken by Norway, Iceland, the Faroes and Greenland. These surveys are established time-series that provide abundance indices for deep-water species e.g. Greenland halibut, to ICES groups AFWG and NWWG. The surveys are similar in their scientific objectives and design and under WGNEACS, efforts have been made to enhance their coordination in terms of spatial and temporal coverage, data collection, management and analysis.
A second survey subgroup deals with the requirements of a coordinated deep-water trawl survey along the Central European slope and associated banks and seamounts stretching from the Faroese Plateau (Vb) to the Goban Spur. A new survey proposal has been presented which extends the spatial coverage to the main distributions of the deep-water fisheries that allows improved estimates of abundance and variance.
The third subgroup deals with existing and proposed surveys in the southern areas (ICES area IX and X, Bay of Biscay, Portuguese continental slope and the Azorean archipelago). Due to topographic features of the region, the main focus has been on longline surveys. An existing longline survey covers the islands from the Azorean archipelago and three main seamounts. The group has also planned and evaluated a new longline survey proposed for the Portuguese continental slope and associated canyons where the main deep-water fisheries take place.