Survey on sessile organisms in Otsuchi Bay

Representative Organization: Atmosphere and Ocean Research Institute The University of Tokyo

2013/04/01 - 2014/03/31
once every three months

Otsuchi Bay

Field survey, Mooring system(Observation buoy)

We deployed settlement panels at different localities in Otsuchi Bay; at each locality panels are spaced at 5 m depth intervals, with a logger for temperature attached to the each set of panels. The goal is to elucidate the seasonality of sessile organisms in different localities in the bay.

Two barnacle species Balanus trigonus and Megabalanus rosa were remarkably abundant in summer. The barnacles showed different distribution patterns in depth; M. rosa tend to be abundant in 5-10 m deep, while B. trigonus was particularly abundant in deeper depth and the lower-surface of the panels. More than 15 genera of encrusting bryozoans were obtained in Otsuchi Bay. The diversity of encrusting cheilostome bryozoan genera was highest in summer to autumn; especially abundant at southern inner-part of the bay. Botryllid colonial ascidians were abundant in autumn and early spring; especially abundant at southern and inner-part of the bay. Most sessile organisms tended to be abundant at southern part of the bay, where the outflow of the water current in the bay containing river water strongly affected. In the early spring, macro-algae tended to be abundant and the sessile organisms decreased.

FY2013 Survey on sessile organisms in Otsuchi Bay

Biological Observation Record (BORAS 7425-7599)
CTD and logger data