426
KOHMAN Y. ARAKAWA
tnhe biodeposition in oyster beds of Matsushirna Bay, Japan, by I t o and
Imai (1955) show that the annual deposition of faecal matter produced
by a raft of cultured oysters (C. gigns) is estimated a t 8-10 tons on a
wet basis. Arakawa et nl. (in press) demonstrated that a raft of oysters
Oct. Oec. Feb. Apr.
Faeces
Pseudofaeces
Mytilus
Oct. Dec. Feb. A!&
Month
Fig. 28. Seasonal rates of biodeposition in Crassostrea ant1 Mytilns (Arakawa et al., in
press).