We collect data on fish stocks in the Baltic Sea, Skagerrak, Kattegatt and Öresund with the help of R/V Svea, SLU's ocean-going research vessel. Our data, analysis and advice form the basis of the EU's common fisheries policy.
Every year we carry out six internationally coordinated trawl surveys in the Baltic Sea, the Bothnian Sea, the Kattegat and the Skagerrak. The aim is to collect fishery-independent estimates of the amount of fish in different areas, as well as the amount of fish larvae. The surveys are international and coordinated by the International Council for the Exploration of the Sea, ICES.
Unlike a professional fisherman who actively searches for fish and streamlines his fishing to get the best catches possible, we try to be as “bad” as possible all the time. We always fish in certain specific areas and with standardized methods. In this way, we get long time series of data that make it possible to compare the development of fish stocks over time.
We study fish that live on the bottom (demersal species such as cod and flatfish) and fish that swim in the open water (pelagic species such as herring and sprat). We also catch eggs and larvae. The surveys are conducted using both trawl and acoustic methods (echo and sonars), and we collect data on species composition as well as the length, weight, age and sexual maturity of the fish.
Our expeditions take place aboard Svea, SLU's ocean-going research vessel. Via marinetraffic.com you can see where Svea is right now >>
The BIAS expedition is carried out annually in September or October in the Baltic Sea and the Bothnian Sea. During the expedition, we estimate the amount of herring and sprat in the sea using trawls, sonars and echo sounders.
Everything about BIAS and where to find data from the expedition can be found in SLU's environmental data catalogue.
We conduct the BITS expedition in the Baltic Sea twice a year, during the first and last quarter. The survey is an international collaboration between several Baltic Sea countries. The main purpose is to collect data on populations of the bottom-dwelling species cod and flounder, but we also record information on all fish that we catch during the expedition.
Everything about BITS and where to find data from the expedition can be found in SLU's environmental data catalogue.
The IBTS expedition is carried out in the Kattegat, Skagerrak and the North Sea twice a year, during the first and third quarter. The main purpose of the expedition is to estimate the occurrence of fish of different ages, especially young fish (recruitment) of commercial species such as cod, haddock, herring, sprat and mackerel.
Everything about IBTS and where to find data from the expedition can be found in SLU's environmental data catalogue.
The target species of the expedition is sprat and takes place in May. The main purpose is to collect information about the stocks in the Baltic Sea. The data we collect is biomass, as well as the sprat's weight, length, age, sex and sexual maturity. We also collect hydrographic data (temperature, salinity and oxygen). The survey is an international collaboration between several Baltic Sea countries.
Everything about SPRAS and where to find data from the expedition can be found in SLU's environmental data catalogue.
SLU Aqua's internationally coordinated fish surveys are carried out in accordance with the DCF (Data Collection Framework), which is a framework for EU countries to collect, manage and share data and statistics from commercial fisheries, recreational fisheries and aquaculture.
Data collection within the DCF is financed to 60 % by funds from the European Maritime, Fisheries and Aquaculture Fund (EMFAF).
Maria Hansson, Environmental Monitoring and Assessment Analyst
Department of Aquatic Resources, Institute of Marine Research, SLU
maria.hansson@slu.se, +46 10 478 40 20, +46 70 231 15 23