Environmental recovery project in Dokai Bay, Kitakyushu, Japan: bioremediation of the organically enriched sediments with a polychaete, Cupitella sp. 1

摘要

The Enviomment of Dokai Bay in Kyushu, Japan, has been suffered fromoccurrence of dissolved oxygen depletion of the bottom water in the seafloor with organically enriched sediments which was accompanied withextreme eutrophicaion of the water. We have conducted the fieldexperiments to treat the organically enriched sediments with biologicalactivities of a deposit feeding polychaete, Capitella sp. I, aiming at furtherrecovery of environmental conditions of the bay. Since the winter in 1996,we cultured dense colonies of Capitella in a factory, and put 1 to 3 kgWWof Capitella on the organically enriched sediments every winter. Due tothe addition of the cultured colonies, the field population of Capitellaincreased more rapidly in early winter, and reached two to four timesdenser patches in the fields than before. The oxidation of the reducedsediments was enhanced by the increase of Capitella. This polychaetehas a potential. for biological agent to treat the organically enrichedsediments.