On the Behavior of Net Fishing Gear Ascertained by Diving Observation -II : Gochi Net in Eguchi Hama

IR (HANDLE) Web Site

Search this article

Description

The Gochi net is commonly operated off the west coast of Kagoshima Prefecture, Japan. Its construction can be divided into two types; with and without a bag. The net without a bag is operated in areas with a rough bottom and complicate configuration. In operating this net, factors which should be taken into consideration include the length of bottom contact, minimum distance between the net and artificial reef, and variation of net mouth. The net operation was analyzed through data from underwater camera and video, tension, depth, and net mouth height meters. The net mouth height at the time of bottom contact was 10-16m. During hauling it decreased to 3-6m. At the time of lift off the bottom, net mouth height ranged from 0.5-1.0m. At this point, fishes were caught in the net. The tension during bottom contact was 10-20kg. During hauling it increased to 25-50kg. Upon lifting off it increased to 60-100kg. Wing distance became narrow after lifting off the bottom. This caused schools of fishes which were in front of the net mouth to become frightened and entangled in the net bunt. Under operating conditions, the net mouth looked like a "tongue", and the phase of hauling like a scoop. Over all hauling rate of the net is shown to be 3-5m/s, which were good condition of net mouth height when the fishes were caught in the front of net and over artificial reef area.

Journal

Keywords

Details 詳細情報について

Report a problem

Back to top