Title Different effects on seaweed succession after sea urchin removal at several coastal waters in Tosa Bay, southern Japan
Authers Seiya TAINO
Keywords Isoyake, sea urchin removal, Anthocidaris crassisspina, Echinometra spp., Sargassum micracanthum, Sargassum siliquastrum, Ecklonia cava
Citation Bull. Fish. Res. Agen. No.32, 61-67, 2010
Abstract
The effectiveness of sea urchin removal for the purpose of regenerating the seaweed bed was studied at several study areas in Tosa Bay. Marine algal succession and density of invaded sea urchins after sea urchin removal were examined at five stations (Kamikawaguchi, Kutsuu, Ikenoura, Tei and Sakamoto). Large perennial algae superseded coralline algae at Kamikawaguchi, Kutsuu and Ikenoura, since the inhibiting factor was removed by sea urchin removal by scuba diving. Furthermore, spores and embryos, tided from near seaweed beds to study area, accelerated regeneration of seaweed bed. On the other hand, seaweed beds have not regenerated after sea urchin removal by SCUBA diving at Tei and Sakamoto, In these stations, it appears that both the feeding activity of sea urchin and the browsing activity of herbivorous fishes inhibited marine algal succession. Fishermen and students removed sea urchins by skin diving at Kamikawaguchi and Kutsuu in 2007. It should be noted that even the skin diving removal of sea urchin have an effect on regeneration of seaweed bed.
URI http://www.fra.affrc.go.jp/bulletin/bull/bull32/61-67.pdf