Analysis of the drift speed and drift direction of fishing gear for pot drift fishing for Enteroctopus dofleini by obtaining positional information

In this study, we aimed to achieve efficient fishing operation by obtaining positional information of fishing gear (pots) used for pot drift fishing for the North Pacific giant octopus Enteroctopus dofleini; this type of fishing is mainly performed in coastal areas of Hokkaido, Japan. We attached GPS watches to fishing pots to obtain positional information, which was then used to calculate the pot drift speed and direction. Based on the results, the average drift speed of the pots was approximately 9 cm/s, and the drift direction was dependent on meteorological and oceanographic phenomena. We suggest that the time at which fishing pots are picked up can be estimated based on changes in drift speed. In future, optimal conditions for pot drift fishing can be estimated by correlating the drift speed and direction with catch amount.