Duration:    May 3 – 28, 2019

Area:    Baltic Sea; Arcona Seat o Gotland Sea

Purpose:   Hydroacoustic survey of sprat

The main objective of this hydroacoustic survey is the annual assessment of small pelagic fish stocks, especially sprat, from the Arkona Sea to the Gotland Sea. This survey is part of the international "Baltic Acoustic Spring Survey", where, in addition to Germany, Estonia, Latvia, Lithuania and Poland are also involved. The survey is coordinated by the ICES working group WGBIFS and has been conducted regularly since 2001. The data will be ultimately used as an index for the stock assessment of sprat.

Main tasks:

• Hydroacoustic detection of sprat, herring and cod in the Arkona Sea to Gotland Sea.
• Fishing with pelagic trawl according to hydroacoustic requirements and biological measurement of catches (species, length composition, sex, maturity and age).
• Sampling of herring, sprat and cod (whole fish, otoliths, stomachs and gonads) for further laboratory studies at the Institute of Baltic Sea Fisheries.
• Hydrographic measurements with CTD probe on predetermined stations and after each fishing station. In case of time constraints, only part of the hydrographic stations will be realized.

Cruise report (PDF, english)