Abstract
The authors investigated the influence of wave velocity on the grazing pressure of the rabbitfish, Siganus fuscescens at the head of the Chita Peninsula of the eastern coast of Ise Bay, where Sagarame (Eisenia arborea) populations have decreased remarkably in recent years. To compare the coast where the Sagarame Forest continues to exist, with that where the forest has vanished, the wave velocity of the seabed was measured from the shore to the offing in October, which is the peak season of grazing in rabbitfish. The waves at the coast where the Sagarame Forest continues to exist were stronger than those at the coast where the Sagarame Forest had vanished. Furthermore, the average wave velocity in the vegetation area of the Sagarame Forest was greater than 23.6cm/s, and the length of this area was about twice the coast where the Sagarame Forest had vanished. These results showed a strong wave velocity lowers the grazing pressure of the rabbitfish.
