Recent observations on the distribution of deep-sea coral communities on the Shiribeshi Seamount, Sea of Japan

Abstract

The benthic deep-water coral fauna of the Shiribeshi Seamount, Japan, was examined using the JAMSTEC video archives of four submersible dives in July 2001. An observational dataset containing n = 2055 records was obtained. The vertical distributions of the deep-water gorgonians Family Primnoidae and Paragorgiidae were determined. Primnoid corals include at least one species, Primnoa resedaeformis pacifica (Kinoshita, 1907) and are distributed between 1030 m and 271 m in depth and at a water temperature of 0.24-1.11ªC. Paragorgiid corals were observed between 491 m and 178 m in depth and at a water temperature of 0.66-1.69ªC, in shallower and warmer areas than primnoid species. It was observed that deep-sea gorgonians on the Shiribeshi Seamount in the North-West Pacific region exhibit family zonation and vertical distribution patterns. The distribution of hydrocorals, unidentified sponges, shrimp, and nudibranchs was also recorded. This is the first report on a deep-sea gorgonian coral community inhabiting Japanese waters.