Abstract
Sessile animals' distribution and their water quality purification function in Tokyo inner bay were investigated. The following results were obtained.
1) In the coastal artificial structure which extends up to 192 km in the Tokyo inner bay, the number of species of sessile animals lies in the range of 43-46 throughout the year. A number of individuals show repetitive phenomena of increasing by the production of larva during spring and autumn which are their breeding period and decreasing during summer and winter when environmental conditions become worse.
2) The predominant four species mainly Mytilus edulis galloprovincialis and the rest Limnoperna fortunei kikuchii, Crassostrea gigas, Balanus spp., account for more than 90% of the biomass of sessile animals. It is presumed that an average of 9, 110t of sesile animals inhabited annually.
3) The sessile animals of Tokyo inner bay are presumed to possess the COD purification ability of 19t per day on the average in year and thus contribute immensely for purification of water environment of Tokyo inner bay.
4) The COD, N and P amounts which have been stored within the sessile animals' tissue are 2,292,127 and 16t per year respectively. These amounts recur to the water environment with sessile animals' longevity.
