ICES explored five management scenarios that could be used to reduce pressure and impact on the seabed caused by bottom trawling and modelled the consequences of their implementation for bottom trawling with vessels greater than 12 m. In this advice, and the accompanying four regional assessments and interactive maps, ICES uses two impact and one pressure (presence or absence of bottom trawling) indicators to describe these consequences.
ICES advises that bottom trawling is the main physical pressure exerted on the seabed across the EU’s marine waters. It is spatially aggregated to form core areas where bottom trawling effort and value of catch is high and larger peripheral fishing areas where effort and value of catch is low. This general pattern is found for all métiers and in all regions.
ICES advises that some levels of bottom trawl fishing can be compatible with achieving seabed conservation objectives. However, a prerequisite for evaluating these objectives will be to define ecologically meaningful limits beyond which continued bottom trawl fishing will have adverse effects. These limits can inform the setting of Good Environmental Status (GES) thresholds for quality and areal extent.
ICES presents management scenarios that balance the economics of bottom trawling with the protection of MSFD broad habitat types by ensuring trawling continues to be concentrated in highly trawled core grounds that are already impacted and reduced in peripheral grounds that are lightly trawled. For example, the results show that collectively for the Baltic Sea, Greater North Sea, Celtic Seas, and Bay of Biscay and Iberian Coast, the removal of less than 10% of the total bottom trawling effort from peripheral fishing grounds will increase the overall extent of untrawled area to more than 40% in each MSFD broad habitat type in each subdivision.