A new paper on the discovery of a new hydrothermal vent field has been published in the peer-reviewed Open Access journal Royal Society Open Science! I acted as the corresponding author. Read for free here: http://rsos.royalsocietypublishing.org/content/4/12/171570
We report, in this paper, the discovery of the “Yokosuka” site – the deepest and hottest hydrothermal vent field in the Okinawa Trough, Japan. At 2190 m deep, this new vent field is highly active and exhibit vigorous focused venting from ‘black smoker’ chimneys, the highest temperature recorded being 364°C.
Vent chimneys in the “Yokosuka site”
Fauna and microbiota in the new site were generally similar to other Okinawa Trough vents, although with some different characteristics. For fauna, the dominance of the deep-sea mussel Bathymodiolus aduloides is surprising given other nearby vent sites are usually dominated by B. platifrons and/or B. japonicus, and a sponge field in the periphery dominated by Poecilosclerida is unusual for vents in this region. In terms of microbiota, the H2-rich vent fluids in one of the chimneys resulted in the dominance of hydrogenotrophic chemolithoautotrophs such as Thioreductor and Desulfobacterium. In terms of vent fluid, notable Cl depletion (130 mM) and high concentrations of both H2 and CH4 (~10 mM) probably result from subcritical phase separation and thermal decomposition of sedimentary organic matter. Our insights from the Yokosuka site implies that although the distribution of vent animal species may be linked to depth, the constraint is perhaps not water pressure and resulting chemical properties of the vent fluid but instead physical properties of the surrounding seawater.
Overview of the “Yokosuka site”
We named the new vent site after R/V Yokosuka, the supporting vessel of DSV Shinkai6500 and AUV URASHIMA.
R/V Yokosuka, which caught the first signs of the “Yokosuka site” using a Multi-Beam Echo Sounder
- Miyazaki J, Kawagucci S, Makabe A, Takahashi A, Kitada K, Torimoto J, Matsui Y, Tasumi E, Shibuya T, Nakamura K, Horai S, Sato S, Ishibashi J, Kanzaki H, Nakagawa S, Hirai M, Takaki Y, Okino K, Watanabe HK, Kumagai H, Chen C* (2017). Deepest and hottest hydrothermal activity in the Okinawa Trough: Yokosuka site at Yaeyama knoll. Royal Society Open Science, 4: 171570. http://dx.doi.org/10.1098/rsos.171570