THE DEVELOPMENT OF BOTTOM IMPROVEMENT TECHNIQUES WITH BIVALVES SHELLS IN CLOSED SEA AREA

Abstract

  To develop techniques for environment improvement and ecosystem restoration in closed sea area such as harbor, we covered waste oyster shells on the sea bottom with 1,000m² and 0.5m in depth and followed the progress for about one year. In/On the covered area, there were 64-94 macro benthos species, included useful animals such as sea cucumbers, baby octopuses and young dabs. That maximum biomass were 3,800 inds /m² and 1.14 kg w.w. /m², which were as 1.9 times in inds and 28.5 times in wet weight as the control area's respectively. Those may cause the muddiness decrease above the covered area with bio-deposition and physical re-cloud suppress. Therefore, it is obvious to cover waste shell can clean up the polluted sea bottom within a relative short period of time.