Utveckling av ett selektivt och sälsäkert burfiske efter torsk i Östersjön

Pots are a passive fishing gear, and the efficiency is dependent on attracting fish to the fishing site. One way to attract fish is to use bait, making it important to investigate how different types of bait attract fish and whether it is possible to extend the bait's effectiveness, i.e., how long the bait can attract cod. Various bait types were included in the evaluation, including regular herring and a mixture of herring and coconut fat. The results showed that herring bait attracted a greater variety of fish species for a longer period compared to herring mixed with coconut fat. In the experiment Summary focusing on testing the different bait types in pots targeting cod, the results indicated that the mixture herring with coconut fat worked better than just sliced herring. Another stimulus that can attract fish is light. This study showed that light in pots increases the catch of cod, especially small-sized cod. Light attracts smaller cod to the pots, likely by attracting plankton and other prey that are food for juvenile cod. The catch efficiency of pots can be affected by both biotic and abiotic factors. In this study, we examined potential variables affecting pot catch efficiency. Test fishing with pots was carried out from 2018 until 2021 off the coast of Ystad. A total of 3449 pots were emptied over 159 fishing days, with the highest catches in 2018. The results show that pot catches vary depending on season, temperature, depth, and year. Square pots with four entrances have the best catch efficiency, while rectangular pots with two entrances catch less cod. Additionally, soak time, depth, and temperature also affect catch results. Catches decreased significantly from 2018 to 2021, likely due to decreased cod stocks in the area. The closure of the cod fisheries in the area that was introduced in 2019 did not seem to have a positive effect on cod abundance in the area in the following years. Finally, the quality of cod caught in pots was studied compared to cod caught in gillnets. Previous studies have shown that cod caught in pots may be in poorer condition than cod caught in gillnets; however, the quality may be better as cod from pots often come up alive, unlike cod caught in gillnets that may have been in the nets under a longer period time. The results indicated that cod from pots were generally leaner than gillnet-caught cod but had fewer injuries and discolorations. Test participants tasted and judged the appearance of cod caught in pots or in gillnets. The fillets from cod from pots were judged more positively than fillets from gillnet-caught fish. However, taste tests showed no differences despite cod from pots having leaner fillets.