Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Solea	797	15.09.2021 - 01.10.2021

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Santos Juan	Thunen-Institut fur Ostseefischerei	Rostock	Rostock

Ziel der Reise / Objectives of Cruise:

This cruise was devoted to fundamental research on codend selectivity. Based on a novel experimental setup involving codends with mesh geometries fixed to a specific opening angle (OA), the main aim of the research was to isolate and quantify the effect of the variability of mesh geometry on the selectivity of Baltic demersal fish species. Selectivity data were collected using the cover-codend method. The analysis of the catch-data revealed that the variation in mesh geometry associated to standard (non-fixed mesh) codends negatively impacts on the sharpness of the selectivity curve for cod, leading wider selection range (SR) than the SR estimated for two experimental codend designs with the mesh opening fixed to respectively 60 and 90 degrees. The experimental results obtained during the cruise validated theoretical predictions regarding the influence of variation in mesh geometry on the selectivity of cod and flatfish species, and should help to open new paths for the development of the demersal trawl codends of the future. In addition, innovative pots gears were deployed in order to evaluate their performance from a engineering point of view. Cod, leading wider selection range (SR) than the SR estimated for two experimental codend designs with the mesh opening fixed to respectively 60 and 90 degrees. The experimental results obtained during the cruise validated theoretical predictions regarding the influence of variation in mesh geometry on the selectivity of cod and flatfish species, and should help to open new paths for the development of the demersal trawl codends of the future. In addition, innovative pots gears were deployed in order to evaluate their performance from a engineering point of view.

Messungen / Measurements