2008, Cefas, Scale and impact of fishing activities in the Eastern English Channel

Description

Extensive research into the ecological impacts of bottom trawling has indicated that fishing activities have the ability to significantly change seabed communities.  Similarly, research into aggregate extraction has provided an understanding of the impacts on benthic communities within and in the vicinity of aggregate extraction sites.  To understand the significance of the impacts caused by aggregate extraction in an area, it is essential to understand the nature and extent of other human activities (e.g. fishing) in the area, as well as how they will impact the seabed environment.  To date, little research has been carried out to compare the impacts of bottom trawling and aggregate extraction on benthic communities and the wider ecosystem.  This project was developed as a pilot study into the nature and extent of fishing impacts and activities in the Eastern English Channel, which would provide the basis for future research into the significance of the impacts of aggregate extraction compared to bottom trawling activities. Using existing geophysical survey data collected in the Eastern English Channel, a methodology was developed to quantify the seabed impact resulting from bottom trawling activities.  Three types of trawl scars could be identified from the sidescan sonar data, and corresponded with scallop dredging, beam trawling and otter trawling.  Maps of the density and spatial coverage of the physical impact as a result of these activities are presented in this report.