Mega- and macrofauna of the hydrothermally active submarine Piip Volcano (the southwestern Bering Sea). (April 2023)

• Record Type: Journal Article
• Authors: Rybakova, Elena; Krylova, Elena; Mordukhovich, Vladimir; Galkin, Sergey; Alalykina, Inna; Sanamyan, Nadezhda; Nekhaev, Ivan; Vinogradov, Georgy; Shilov, Vladimir; Pakhnevich, Alexey; Gebruk, Andrey; Adrianov, Andrey
• Is Part Of: Deep sea research. Volume 208(2023)
• Publication Date: 2023-04
• Subjects: Hydrothermal vent community -- Pacific Ocean -- Image analysis -- Vesicomyidae -- Obligate species -- Reducing environment -- Chemosynthetic habitats -- Biogeography; Oceanography -- Periodicals; Ocean bottom -- Periodicals; Marine biology -- Periodicals; 551.46
• DOI: 10.1016/j.dsr2.2023.105268
• Languages: English
• ISSNs: 0967-0645

Abstract

Abstract: Benthic communities of the hydrothermally active submarine Piip Volcano (55°445 N, 167°263 E, 368–495 m, the southwestern Bering Sea) were explored during the 75th and 82nd cruises of the RV Akademik M.A. Lavrentyev using the ROV Comanche 18 . The Piip Volcano is the northernmost hydrothermal region in the Pacific. Macrofauna composition and community structure were investigated based on qualitative and relative abundance samples along with still images and video records. In total, 130 species of macro- and megafauna were found, of which ∼25% are new to science. Of the fauna, 9 species (7%) are obligate or potentially obligate to environments with access to reduced chemicals. These species are the bivalve Calyptogena pacifica (Vesicomyidae: Pliocardiinae), the gastropods Parvaplustrum wareni (Parvaplustridae) and Provanna sp. (Provannidae), the amphipod Onesimoides sp. (Tryphosidae), the leptostracan Nebalia piipensis (Nebaliidae), the isopod Eurycope andreyi (Munnopsidae), and the polychaetes Neosabellides uschakovi (Ampharetidae), Ophryotrocha beringiana (Dorvilleidae) and Harmothoe globosa (Polynoidae). The total species richness of the Northern and Southern summits was almost identical (90 species and 85 spp respectively), but the number of species on sites without bacterial mats on the Northern Summit (81 spp) was almost 1.5 times higher than on the Southern Summit (57 spp). At the same time the species richness was almost twice higher in habitats with bacterial mats and/or clam beds on the Southern Summit (58 spp) compared to the Northern one (32 spp). The main faunal difference was the absence of Calyptogena pacifica on the Northern Summit. The factors that may explain differences of the faunal communities of the Northern and Southern summits are discussed. The distinctive features of macro- and megafaunal communities of the Piip Volcano were the significant number of taxa, obligate for reducing habitats, of different taxonomic levels including family and subfamily levels and plentiful abundances of sedentary organisms, including the sea anemone Corallimorphus cf. pilatus, the demosponge Vulcanella koltuni, calcareous sponges and benthopelagic Trachimedusa, all of them presumably utilizing the rich food resources of reducing habitats. Highlights: 130 mega- and macrofaunal species were found on the hydrothermally active Piip Volcano at 368–495 m depth. Among 9 species presumably obligate to reducing habitats, 5 were also recorded from seeps outside the volcano. Numerous sedentary organisms found at bacterial mats, were also known from regular habitats outside the Piip Volcano. Calyptogena beds were present only on the Southern Summit. Species richness at bacterial mats and clam beds on the Southern Summit was twice as high as that of the Northern Summit.