The Pattern of Fishing Ground Use of Longline Fishing (Haenawa) at Mukuna in the Ochi Islands

Abstract

The aim of this report is to describe the pattern of fishing ground use of longline fishing at Mukuna in Oshima Island, Ehime Prefecture. To study some aspects of longline fishing the author made a field survey in the ecological point of view. The the author's method has been wanting in the field research of geography of fisheries so far. The data of this report, therefore, was obtaind by a diarect observation method in addition to hearing and collecting documents in the field.The results of the research can be summarized as follows.1) Longline fishing is operated throughout one year. The fishing season is divided into two categories by seasonality of catch; in November to April hogonawa catching mainly hogo (Sebastiscus marmoratus) is operated, while in May to October tamorinawa catching tamori (Hapalogenys mucronatus) and anago (Astroconger myriaster) is operated.2) Feeding habit of fish limits the time of the longline fishing operation. The hogo is diurnal, while the tamori and the anago are nocturnal. Hogonawa, therefore, is operated in the daytime, while tamorinawa is carried out early in the morning and the nighttime.3) The longline fishing must be operated in time-zone, called toromi, in which tidal movement changes from ebbing to flowing and from flowing to ebbing.4) There are 21 fishing grounds of longline fishing around Mukuna. They are divided into four categories by toromi.a. fishing grounds usable at toromi of ebb tideb. fishing grounds usable at toromi of flow tidec. fishing grounds usable at both toromi of ebb and flow tided. fishing ground not having relation to toromi5) Each fisherman in general uses only 1 to 5 fishing grounds where he is very familiar with conditions of tide, sea bottom, and so on.6) The activity of longline fishing is divided into three categories: (a) preparing for going out fishing at the port, (b) operating at the sea, and (c) landing catch and taking care of fishing gears at the port. The total time necessary for activity of (a), (b), and (c) is about 600 to 700 minutes. Therefore it is impossible for the fisherman to operate more than two times a day.