scholarly journals Deepest and hottest hydrothermal activity in the Okinawa Trough: the Yokosuka site at Yaeyama Knoll

2017 ◽  
Vol 4 (12) ◽  
pp. 171570 ◽  
Author(s):  
Junichi Miyazaki ◽  
Shinsuke Kawagucci ◽  
Akiko Makabe ◽  
Ayu Takahashi ◽  
Kazuya Kitada ◽  
...  
Keyword(s):  
Hydrothermal Vents ◽  
Okinawa Trough ◽  
Water Pressure ◽  
Chemical Properties ◽  
Hydrothermal Activity ◽  
Future Research ◽  
Depth Range ◽  
Fluid Temperature ◽  
The Okinawa Trough ◽  
Ryukyu Arc

Since the initial discovery of hydrothermal vents in 1977, these ‘extreme’ chemosynthetic systems have been a focus of interdisciplinary research. The Okinawa Trough (OT), located in the semi-enclosed East China Sea between the Eurasian continent and the Ryukyu arc, hosts more than 20 known vent sites but all within a relatively narrow depth range (600–1880 m). Depth is a significant factor in determining fluid temperature and chemistry, as well as biological composition. However, due to the narrow depth range of known sites, the actual influence of depth here has been poorly resolved. Here, the Yokosuka site (2190 m), the first OT vent exceeding 2000 m depth is reported. A highly active hydrothermal vent site centred around four active vent chimneys reaching 364°C in temperature, it is the hottest in the OT. Notable Cl depletion (130 mM) and both high H 2 and CH 4 concentrations (approx. 10 mM) probably result from subcritical phase separation and thermal decomposition of sedimentary organic matter. Microbiota and fauna were generally similar to other sites in the OT, although with some different characteristics. In terms of microbiota, the H 2 -rich vent fluids in Neuschwanstein chimney resulted in the dominance of hydrogenotrophic chemolithoautotrophs such as Thioreductor and Desulfobacterium . 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 OT vents. Our insights from the Yokosuka site implies that although the distribution of 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. The potential significance of these preliminary results and prospect for future research on this unique site are discussed.

scholarly journals Regional oceanographic features and hydrothermal activity influence protist diversity and biogeography in the Okinawa Trough

2019 ◽  
Author(s):  
Margaret Mars Brisbin ◽  
Asa E. Conover ◽  
Satoshi Mitarai
Keyword(s):  
Hydrothermal Vents ◽  
Okinawa Trough ◽  
Hydrothermal Activity ◽  
Water Masses ◽  
Mass Composition ◽  
Rare Biosphere ◽  
Environmental Selection ◽  
The Okinawa Trough ◽  
Dispersal Barriers ◽  
Bottom Waters

AbstractMicrobial eukaryotes (protists) contribute substantially to ecological functioning in marine ecosystems, but factors shaping protist diversity, such as dispersal barriers and environmental selection, remain difficult to parse. Deep-sea water masses, which form geographic barriers, and hydrothermal vents, which represent isolated productivity hotspots, are ideal opportunities for studying the effects of dispersal barriers and environmental selection on protist communities. The Okinawa Trough, a deep, back-arc spreading basin, contains distinct water masses in the bottom waters of northern and southern regions and at least twenty-five active hydrothermal vents. In this study, we used metabarcoding to characterize protist communities from fourteen stations spanning the length of the Okinawa Trough, including three hydrothermal vent sites. Significant differences in community structure reflecting regional oceanography and water mass composition were present, indicating the importance of geographic factors in shaping protist communities. Protist communities in bottom waters affected by hydrothermal activity were significantly different from communities in other bottom waters, suggesting that environmental factors can be especially important in shaping community composition under specific conditions. Amplicon sequence variants that were enriched in hydrothermally influenced bottom waters largely derived from cosmopolitan protists that were present, but rare, in other near-bottom samples, thus highlighting the importance of the rare biosphere.

scholarly journals Population connectivity of the crab Gandalfus yunohana (Takeda, Hashimoto & Ohta, 2000) (Decapoda: Brachyura: Bythograeidae) from deep-sea hydrothermal vents in the northwestern Pacific

2020 ◽  
Vol 40 (5) ◽  
pp. 556-562
Author(s):  
Hiromi K Watanabe ◽  
Chong Chen ◽  
Shigeaki Kojima ◽  
Shogo Kato ◽  
Hiroyuki Yamamoto
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vents ◽  
Okinawa Trough ◽  
Coi Gene ◽  
Genetic Connectivity ◽  
Reverse Direction ◽  
Northwestern Pacific ◽  
Brachyuran Crab ◽  
The Okinawa Trough ◽  
Mariana Arc

Abstract Genetic connectivity provides a basis for evaluating the resilience of animal communities by elucidating gene flow and serves as a proxy for realized dispersal through planktonic larval dispersal, settlement, and reproductive success. Gandalfus yunohana (Takeda, Hashimoto & Ohta, 2000) is a brachyuran crab endemic to deep-sea hydrothermal vents in the northwestern Pacific. Although an iconic and often dominant species, the connectivity among its populations is yet to be examined. We obtained barcoding sequences of the mitochondrial COI gene of G. yunohana from four vent fields including two on the Izu Arc, one on the northern Mariana Arc, and one in the Okinawa Trough. Genetic diversity of populations on the Izu and northern Mariana arcs were similar and shared the dominant haplotypes, showing no genetic subdivision regardless of the habitat depth. The Okinawa Trough population, for which only one specimen was available, was not genetically different from specimens from the Izu/Mariana arc populations. Estimation of the number of immigrants among populations suggests that the migration from north to south is higher than in the reverse direction. Our results resonate with previous laboratory-culture experiments, suggesting a high dispersal capability for G. yunohana. Visual observations and sampling, however, suggest that G. yunohana is exceedingly rare in the Okinawa Trough. This perhaps results from a lack of sufficient larval supply from the Izu-Bonin-Mariana Arc vents, and there may not be a reproductive population in the Okinawa Trough.

Records of species of the hippolytid genus Lebbeus White, 1847 (Crustacea: Decapoda: Caridea) from hydrothermal vents in the Pacific Ocean, with descriptions of three new species

Zootaxa ◽  
2012 ◽  
Vol 3241 (1) ◽  
pp. 35 ◽  
Author(s):  
TOMOYUKI KOMAI ◽  
SHINJI TSUCHIDA ◽  
MICHEL SEGONZAC
Keyword(s):  
New Species ◽  
Pacific Ocean ◽  
Hydrothermal Vents ◽  
Okinawa Trough ◽  
East Pacific Rise ◽  
East Pacific ◽  
The Okinawa Trough ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Three New Species

Five species of the hippolytid shrimp genus Lebbeus White, 1847 are reported from various deep-water hydrothermal ventsites in the Pacific Ocean: L. laurentae Wicksten, 2010 from the East Pacific Rise 13°N; L. wera Ahyong, 2009 from theBrothers Seamount, Kermadec Ridge, New Zealand; L. pacmanus sp. nov. from the Manus Basin, Bismarck Sea; L.shinkaiae sp. nov. from the Okinawa Trough, Japan; and L. thermophilus sp. nov. from the Manus and Lau basins, south-western Pacific. Lebbeus laurentae is fully redescribed because the original and subsequent descriptions are not totallydetailed. Differentiating characters among the three new species and close allies are discussed. Previous records of Lebbeus species from hydrothermal vents are reviewed.

scholarly journals Draft Genome Sequence of Exiguobacterium sp. HVEsp1, a Thermophilic Bacterium Isolated from a Deep-Sea Hydrothermal Vent in the Okinawa Trough

2017 ◽  
Vol 5 (17) ◽  
Author(s):  
Chen Chen ◽  
Li Sun
Keyword(s):  
Genome Sequence ◽  
Deep Sea ◽  
Hydrothermal Vent ◽  
Hydrothermal Vents ◽  
Sequence Data ◽  
Okinawa Trough ◽  
Draft Genome ◽  
Thermophilic Bacterium ◽  
Draft Genome Sequence ◽  
The Okinawa Trough

ABSTRACT We report here the draft genome sequence of Exiguobacterium sp. HVEsp1, a thermophilic bacterium isolated from a deep-sea hydrothermal vent. The estimated genome size of this strain is 2,838,499 bp with a G+C content of 48.2%. The genome sequence data provide valuable information that will facilitate studies on the adaptation mechanisms of bacteria living in deep-sea hydrothermal vents.

A new species of Parandania (Amphipoda, Stegocephalidae, Parandaniinae) from the Okinawa Trough

Crustaceana ◽  
2019 ◽  
Vol 92 (11-12) ◽  
pp. 1427-1434
Author(s):  
Yanrong Wang ◽  
Chaodong Zhu ◽  
Zhongli Sha ◽  
Xianqiu Ren
Keyword(s):  
New Species ◽  
Hydrothermal Vents ◽  
Okinawa Trough ◽  
The Okinawa Trough ◽  
Fourth Species ◽  
A New Species

Abstract A new species of Stegocephalidae, Parandania unicoxae sp. nov., is reported from hydrothermal vents in the Okinawa Trough. It is the fourth species described in the genus Parandania Stebbing, 1899. The new species is most similar to P. boecki (Stebbing, 1888), but it can be readily distinguished from P. boecki by the unilobate coxae 6-7.

scholarly journals Understanding the Compositional Variability of the Major Components of Hydrothermal Plumes in the Okinawa Trough

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Zhigang Zeng ◽  
Xiaoyuan Wang ◽  
Chen-Tung Arthur Chen ◽  
Haiyan Qi
Keyword(s):  
Large Scale ◽  
Okinawa Trough ◽  
Chemical Properties ◽  
Hydrothermal Plume ◽  
Plume Water ◽  
Southern Okinawa Trough ◽  
The Okinawa Trough ◽  
Water Columns ◽  
Hydrothermal Plumes ◽  
Hydrothermal Fields

Studies of the major components of hydrothermal plumes in seafloor hydrothermal fields are critical for an improved understanding of biogeochemical cycles and the large-scale distribution of elements in the submarine environment. The composition of major components in hydrothermal plume water column samples from 25 stations has been investigated in the middle and southern Okinawa Trough. The physical and chemical properties of hydrothermal plume water in the Okinawa Trough have been affected by input of the Kuroshio current, and its influence on hydrothermal plume water from the southern Okinawa Trough to the middle Okinawa Trough is reduced. The anomalous layers of seawater in the hydrothermal plume water columns have higher K+, Ca2+, Mn2+, B3+, Ca2+/SO42-, and Mn2+/Mg2+ ratios and higher optical anomalies than other layers. The Mg2+, SO42-, Mg2+/Ca2+, and SO42-/Mn2+ ratios of the anomalous layers are lower than other layers in the hydrothermal plume water columns and are consistent with concentrations in hydrothermal vent fluids in the Okinawa Trough. This suggests that the chemical variations of hydrothermal plumes in the Tangyin hydrothermal field, like other hydrothermal fields, result in the discharge of high K+, Ca2+, and B3+ and low Mg2+ and SO42- fluid. Furthermore, element ratios (e.g., Sr2+/Ca2+, Ca2+/Cl−) in hydrothermal plume water columns were found to be similar to those in average seawater, indicating that Sr2+/Ca2+ and Ca2+/Cl− ratios of hydrothermal plumes might be useful proxies for chemical properties of seawater. The hydrothermal K+, Ca2+, Mn2+, and B3+ flux to seawater in the Okinawa Trough is about 2.62–873, 1.04–326, 1.30–76.4, and 0.293–34.7 × 106 kg per year, respectively. The heat flux is about 0.159–1,973 × 105 W, which means that roughly 0.0006% of ocean heat is supplied by seafloor hydrothermal plumes in the Okinawa Trough.

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