浮魚礁への魚の蝟集機構

抄録

In order to investigate aggregating effect of an artificial fish reef, it is necessary to take into consideration two sides of influence by the economic effect and fishes resource environment by the increase in a fish catch. Since FAD is installed for the purpose of collecting the fishes of a large size and a medium size and fishing efficiently in the offing where individual density is low, evaluation of only the economic effect for a useful fish stock may bring about the increase in fish catch pressure. In order to evaluate the aggregating effect of a fish reef, it is necessary combining some examination methods to investigate the whole resource environment of a fishery. Especially the method of combining optical observations and a split beam echo sounder investigation is effective in order to evaluate fish resource environment comprehensively. The payaw investigation in the Philippines and the artificial fish reef investigation in the Kagoshima bay were conducted combining split beam echo sounder and optical observations. The results of these investigations are described by this paper. For sustainable fish resource use, it is important to decide a suitable fishing method and period using the investigation results.