Denmark’s research vessel Dana will join an international survey in the Norwegian Sea from 27 April to 21 May 2026 to collect data on Atlanto-Scandian herring and blue whiting stocks.
The survey is part of the annual International Ecosystem Survey in the Norwegian Sea (IESNS). It brings together research vessels and scientists from several European countries to assess key pelagic fish stocks.
International survey effort
The work involves scientists from Denmark, Germany, Ireland, Sweden and the Netherlands. Research vessels from Norway, Iceland, the Faroe Islands and the United Kingdom also take part.
The survey covers most of the Norwegian Sea over a six-week period. It aims to give a snapshot of stock size and distribution of herring and blue whiting.
The programme has run every year since 2004 and is coordinated through the ICES working group on pelagic surveys.
Data collection at sea
Scientists use hydro-acoustic methods to detect fish along planned transects. Short fishing hauls confirm species, size and age.
Plankton samples are taken every 60 nautical miles. These show food availability. At the same stations, crews record salinity and temperature from the surface down to 1,000 metres.
Basis for quota advice
All data are combined and analysed by ICES. The results are used to estimate biomass and track stock distribution.
This forms the basis for scientific advice on herring and blue whiting. Authorities use this advice when setting fishing quotas and rules.
The survey also supports research into how ocean conditions affect the migration of pelagic fish.