Publication Abstract

In 2006 CEFAS initiated a beam trawl survey in the Western English Channel based on a stratified random design. The hope is that in the future the data will reduce the reliance on fisheries dependent information in stock assessments for Western Channel sole and plaice stocks. A crucial factor in the success of this sort of survey design is the suitability of the strata describing more or less homogenous entities. The original strata implemented in the design are based on spatial and temporal information from fishermen, interpolated geological seabed maps and large scale bathymetric measurements. It is important to corroborate the suitability of the strata to identify habitats spatially, and to do this for the area as a whole.

 

This study examines whether the species composition of beam trawl catches at the 80 stations sampled in 2007 is consistent with the current design of the strata. We test the ability of a number of acoustic methodologies such as multibeam sonar and QTC View, to describe these habitats through the relationships between several acoustic variables and the fish community. Finally, the efficacy of using these methodologies as indicators of habitats in spatially defining strata boundaries and locations is examined.