Scientific cruise

Havfisken on a survey in Skagerrak, Kattegat, and the Great Belt

On this survey, the research vessel primarily collects data on the sole stock.

Forskningsskibet Havfisken — Research vessel Havfisken. Photo: Helle Falborg.

From 3 to 18 November 2025, the research vessel Havfisken will be in Skagerrak, Kattegat, and the Great Belt to collect data on the sole stock.

The purpose of the survey is to establish and maintain a time series of data independent of commercial fishing, in order to strengthen the biological advice regarding the sole stock. The survey is conducted once a year.

In addition to Havfisken, a commercial vessel will also participate in the survey for 12 days from early November to mid-December. Havfisken covers the more northern stations, while the commercial vessel covers the southern part of the survey area.

A finer-meshed fishing gear than what is allowed in the commercial fisheries is used. This is done to catch some of the smaller soles – recruits – and thereby determine the size of the new year classes.

What data is collected?

During the survey, Havfisken collects data on the sole population by fishing at 90 stations in exactly the same way year after year. The fish’s size, age, sex, and spawning maturity are recorded.The sampling takes place at night, as soles are nocturnal. Data on other commercially important species is also collected.

What is the data used for?

The results are used in the International Council for the Exploration of the Sea's (ICES) biological advice on the status of the sole and other fish stocks. The advice is targeted at authorities, who use it as a basis when setting fishing quotas and other regulations for fisheries.