Study on propagating function of fisheries facilities, 1: Distribution of small animal at and around artificial reefs
2008
Ito, Y.(Japanese Inst. of Technology on Fishing Ports, Grounds and Communities, Tokyo (Japan)) | Nakano, Y. | Fujisawa, S.
In order to quantitatively clarify the change of prey animals with artificial reef installation, we have investigated the distribution and the seasonal variation of epiphytic algae and small animals on and around the reefs in two sites, Seto Inlands Sea and Sea of Japan, for two years. As results, amphipods had majority as phytal animals and their seasonal prevalence followed the lifecycle of algae on the reefs. Important prey animals such as decapods were observed in the reefs with various rooms among materials. These prey animals were less observed in the no-room reefs consistently. Benthic animals increased by the bottom sediment variation due to reef installation. Furthermore, not only sessile and infiltrate animals inhabiting reef materials but phytal animals inhabiting epiphytic algae were additionally observed. Zooplankton around the reefs were gathered and scattered by currents. These suggests the followings ; 1) many small animals classified as prey item for fish make biological reproduction at reef ecosystem, 2) to make many various rooms in the reef is effective for production of small animals, and 3) these animals made their biota complicate by spreading or migrating around the reefs. It's also suggested that the site characteristics and reef materials have species variety, biomass and distribution range.
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