9:45 AM - 10:00 AM
[BPT05-04] Transportation processes of organic matter from whale bones during formation of whale-fall communities
Keywords:Whale-fall community, Chemical synthesis
Characteristic species for the shallow water whale-fall communities such as Xenoskenea sp., dorvilleid polychaeates, white microbial mat (Beggiatoa spp., indicator of sulphophilic stage) and ciliate Zoothamnium sp. (indicator of sulphophilic stage) can be observed at time of recovery and during aquarium experiments (most time). As a result of observations of aquariums, accumulations of several types of fecal excretions around the whale bones were observed. 4 types of the excretion style of feces were observed. Transport distance of feces from the bones are depending on the styles. Total organic carbon content (TOC) analysis showed higher contents at shorter distances from the bones.
Occurrences of Zoothamnium sp. (host of eposymbiotic chemosynthethic bacteria), giant Sulphur-oxidizing bacteria and Xenoskenea sp., dorvilleid polychaeates in/on the bones suggest that our aquarium experiments could form shallow water whale-fall communities. From the results of TOC analysis and many feces were observed around the whale bone, it was suggested that organic matter inside the whale bone is transported to the outside of the bone due to excretion of feces. In this study, we observed not only the transportation process that organic matter is eaten and excreted as feces, but also processes related to giant Sulphur-oxidizing bacteria. Detailed observation by further aquarium experiments will make it possible to clarify the whole movement of organic matter around the whale bones.