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

Abstract

In this study, we aimed to achieve e‹cientˆshing operation by obtaining positional information ofˆshing gear (pots) used for pot driftˆshing for the North Paciˆc giant octopus Enteroctopus do‰eini; this type ofˆshing is mainly performed in coastal areas of Hokkaido, Japan. We attached GPS watches toˆshing 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 whichˆshing pots are picked up can be estimated based on changes in drift speed. In future, optimal conditions for pot driftˆshing can be estimated by correlating the drift speed and direction with catch amount.

World Octopus Fisheries

“…The majority of the GPO catch is attributed to floating-barrel drift lines (Sano, 2017;Taka and Wada, 2018). This method is used off the Hokkaido subprefectures of Sōya, Rumoi, Ishikari, Shiribeshi, Hiyama, and Oshima (ref.…”

“…The different kinds of bait and tackle are known by many local community names. A drift fishing line is used in coastal waters of Hokkaido (Japan) for the fishery of E. dofleini (Taka and Wada, 2018) and a particular system of multiple fishing lines from a vessel is the al garete fishing style, using fresh or rubber crabs to attract O. maya (Markaida et al, 2015;Figure 9). This style of fishing consists of the use of three small boats: a larger one of 5-8 m in length equipped with an outboard motor, carrying in its interior one or two smaller alijos, each of 2.5 m length.…”