Abstract
We have monitored the fish fauna and coral cover at permanent transects on a reef flat, an offshore moat near a reef flat, and a moat near shore at Urasoko Bay, Ishigaki IsI., Japan. In August 1998, we observed severe coral bleaching on the reef. We compared the fish fauna before and two years after this coral bleaching episode to examine the effects of the coral bleaching on fish community structure, and particularly upon fishes of the family Pomacentridae. The benthic substrata on the reef flat and offshore moat consisted mostly of living Acropora spp. before the summer of 1998, however, most of the living coral had died after the coral bleaching. In contrast, the benthic substrata at the near shore moat consisted mostly of dead coral rubble and sand, with several microatolls of massive Porites sp corals. This living coral was not affected by the bleaching episode. On the reef flat, herbivore pomacentrids, Stegastes fasciolatus and Pomacentrus bankanensis, were abundant until two years after the coral bleaching. In the offshore moat, however, the planktivorous pomacentrid Pomacentrus moluccensis, whose abundance decreased on the reef flat after the coral bleaching, was abundant after the coral bleaching. This change was probably dependent upon the remaining of structural complexity of the remaining coral branches in the offshore moat during the two years after the coral bleaching. In the near shore moat, omnivorous Pomacentrus sp. (Japanese name: Minami-isosuzumedai) was abundant in the surveys before and after the coral bleaching.
