SPRAS – Sprat Acoustic Survey

Internationally coordinated hydroacoustic expeditions under the Sprat Acoustic Survey (SPRAS), an International Council for the Exploration of the Sea (ICES) survey programme, are carried out annually. The main objective of the survey is to show the changes in the fish stock (index) and geographical distribution of fish (target species is sprat).

The expeditions are carried out in May and are an international collaboration between several Baltic Sea countries. Since 2019, the Swedish expeditions have been carried out with SLU's research vessel R/V Svea. Data collected are the amount of biomass, as well as the weight, length, age, sex and sexual maturity of the sprat. Hydrographic data is also collected (temperature, salinity and oxygen).

The Baltic Sea countries meet in the Baltic International Fish Survey Working Group (WGBIFS) and the results from each country are compiled in a common database. WGBIFS also develops common guidelines and manuals. The results form the basis for the WGBFAS estimate of the total stocks of herring and sprat in the Baltic Sea.

Data can be downloaded from the ICES website: Acoustic trawl surveys.

Please note that SPRAS is called BASS in the ICES database. Therefore, to find SPRAS data, use the filter Survey-code=BASS in the web interface.