The goal of this year’s TESO (Marsdiep) survey, is to study pelagic (open water) fish schools on the border between the Wadden Sea and the North Sea, using fisheries acoustics techniques. The survey is funded by NWO, and will be carried out using the GO58 Jakoriwi, with Sven Gastauer and Gerrit Rink from IMARES on board.
Hence a calibrated towed body equipped with echosounders of two frequencies, 38 and 200 kHz, will be used allowing the detection of fish schools and to a certain extend a distinction between different species.
Fishing will be executed to allow a comparison between biological samples and the pictures, so called echograms, provided by the echosounder. This should result in a rather accurate estimate of the species composition and abundance in the surveyed area. Furthermore salinity and temperature will be constantly measured. Two parameters believed to have a major influence on the different fish species and the ecosystem as a whole.