Abstract
The present study identified the characteristic attached diatoms derived from Shiretoko Rausu Deep Seawater (DSW) pumped from a depth of 218 m in Okhotsk Sea. Diatom samples were collected from a DSW tank seasonally from December 2004 to December 2005 and identified using light and scanning electron microscopy. A totalof 11 species in 7 genera were recorded. The most common taxa encountered were Amphora sp. and Cocconeis sp. 1. Amphora sp. was dominant from winter to spring and thereafter decreased gradually, whereas Cocconeis pinnata and Cocconeis sp. 1 increased from spring to summer. Navicula sp. 1 and Nitzschia tubicola were common but decreased in summer. Tabularia investiens was in constant occurrence. Theoverall attached diatom flora in Shiretoko Rausu DSW was different from those previously observed by the authors in other DSW facilities (Namerikawa, Nyuuzen and Muroto) in Japan. In the present paper, morphologic and taxonomic comments were given for the above 5 species as well as the other two species, Achnanthes sp. and Tryblionella sibula.
