Duration: 28 July bis 17 August 2025

Cruise area: North Sea

Purpose: German Small-scale Bottom Trawl Survey

Since 1987, the Thünen Institute of Sea Fisheries has been using the German Small-scale Bottom Trawl Survey (GSBTS) to determine small-scale abundances and distribution patterns of bottom fish in the North Sea. To this end, annual surveys are carried out in 12 standard survey areas ("boxes"), each measuring 10 x 10 nautical miles, using a standardised bottom trawl. This data set forms an important basis for assessing long-term changes in the bottom fish fauna of the North Sea caused by natural (e.g. climatic influences) or anthropogenic factors (e.g. fishing).

The fisheries research vessel Solea uses standardised methods to fish four of these boxes in just under three weeks. Passive fishing with baskets for crab is also carried out around wind farms, as well as plankton surveys. In addition, eDNA samples are collected to allow a comparison of eDNA and trawl sampling.