Trapping efficiency and retention ability of four pontoon trap entrance types for use in coastal cod fishing, a fishing gear development field trial in the Baltic sea

Abstract: As the Baltic Sea cod gets smaller both in number and size, and the grey seal population continues to increase, the need for alternative fishing methods in coastal fisheries increases. In this project one commercially used and three experimental pontoon trap entrances are tested with the objective to investigate if there are differences in trapping efficiency and retention ability when fishing for cod. The four entrance types were installed in fish pots together with video cameras and lights. From the recorded video material the number of Enter, Exit, Approach and Turn events were logged and used to calculate trapping efficiency (Enter/Approach ratio) and retention ability (Exit/Enter ratio). There was a statistically significant difference trapping efficiency between Narrow-Short and Narrow-Long, both indicating that Narrow has a lower trapping efficiency. Due to limitations in analyses of the recorded observations, clear conclusions may not be drawn from the study's results. There is a need for further research focusing on entrance types for pontoon traps in order to develop seal safe gear with increased catch efficiency.