Expeditionsrapport IBTS, januari 2022

The IBTS survey is conducted twice annually, in quarters 1 and 3 and covers the Skagerrak, the Kattegat and a small part of the eastern North Sea. The French bottom trawl GOV is used for the fishing daytime while in Q1 only, a MIK trawl is used at night for sampling fish larvae. During this survey 37 valid hauls were towed using the GOV-trawl, 5 in the North Sea, 17 in the Skagerrak and 15 in the Kattegat.The total catch amounted to 5,85 tonnes (almost 60% being clupeids) and comprised 63 species of fish. Biological sampling was carried out on the most important commercial species including otoliths taken for age analysis. In total 3431 otoliths were collected from 12 different species. For the target species, preliminary indices of the one-year group were calculated.MIK trawling resulted in 46 valid trawl hauls with catches of 262 herring larvae, 138 sardine larvae, one eel larvae but no sprat larvae.