Characteristics of the Environment Around a Massive Sea-Floor Sulfide Area in the Okinawa Trough

2011 ◽  
Author(s):  
Hiroshi Ishida ◽  
Nobuhiro Maeda ◽  
Tetsuya Miwa ◽  
Tetsuo Yamazaki ◽  
Yoshihisa Shirayama ◽  
...  
Keyword(s):  
Hydrothermal Vent ◽  
Okinawa Trough ◽  
Euphotic Zone ◽  
Bottom Layer ◽  
Massive Sulfide ◽  
Baseline Survey ◽  
Surrounding Area ◽  
Sea Floor ◽  
The Okinawa Trough ◽  
Ca 50

It is necessary to carry out a proper environmental impact assessment for not only the sea-floor massive sulfide area where a special hydrothermal-vent chemosynthetic ecosystem is observed, but also its surrounding area. This paper shows provisional results of the environmental baseline survey conducted at the Izena Cauldron in 2009. Environmental conditions differed clearly between inside and outside of the Cauldron. In the inside area, a high turbidity layer was recognized at ca. 200 m above the sea-floor. In the bottom layer close to the hydrothermal active region, water temperature was slightly higher than the surrounding area with the lower pH, higher concentrations of both carbon dioxide and the dissolved Mn. Inside the Cauldron, the sulfur isotope ratio of the sediment close to a sea-floor massive sulfide was similar to that of the hydrothermal sulfate. In addition, heavy metal concentrations of the sediment were higher inside than outside of the Cauldron. Especially, concentrations of Cd, As and Hg were as high as poisonous levels. These results show the possibility that most of the chemical materials derived from hydrothermal vent remain in the Cauldron. Pelagic shrimps of the family Oplophoridae were widely distributed in the bottom layer inside the Cauldron. The biomass of benthic shrimps which belong to infraorder Caridea was higher inside than outside of the Cauldron. These higher biomass was likely caused by the abundant organic matter. This hypothesis was reinforced by the result of the mooring sediment trap (placed at ca. 50 m above the seafloor) experiment, which demonstrated that the settling particle in the Cauldron was supplied from not only the euphotic zone but also the hydrothermal-vent ecosystem.

scholarly journals ESR Dating of Barite in Sea-Floor Hydrothermal Sulfide Deposits in the Okinawa Trough

2014 ◽  
pp. 369-386 ◽  
Author(s):  
Taisei Fujiwara ◽  
Shin Toyoda ◽  
Ai Uchida ◽  
Jun-ichiro Ishibashi ◽  
Shun’ichi Nakai ◽  
...  
Keyword(s):  
Okinawa Trough ◽  
Esr Dating ◽  
Sulfide Deposits ◽  
Sea Floor ◽  
Hydrothermal Sulfide ◽  
The Okinawa Trough

A new species of the genus Neoverruca (Cirripedia, Thoracica, Verrucidea, Neoverrucidae) from a hydrothermal vent area in the Okinawa Trough

Crustaceana ◽  
2015 ◽  
Vol 88 (9) ◽  
pp. 991-1001 ◽  
Author(s):  
Zhong-Li Sha ◽  
Xian-Qiu Ren
Keyword(s):  
New Species ◽  
Hydrothermal Vent ◽  
Distal Part ◽  
Okinawa Trough ◽  
Longitudinal Ridge ◽  
Longitudinal Groove ◽  
The Okinawa Trough ◽  
Inner Surface ◽  
A New Species

A new species of the neoverrucid barnacle genusNeoverrucaNewman, 1989,N. intermediasp. nov., collected from a hydrothermal vent area in the Okinawa Trough, is described and illustrated. It differs fromN. brachylepadoformisNewman, 1989 by the apical end of the inner surface of the movable scutum being in a pocket-form, with a longitudinal groove upwards, and without median ridges; the adductor ridge (or myophore) of the fixed scutum stout and the inner distal part of the scutum without longitudinal ridge.

New ways for research and development using a deep-sea hydrothermal vent system in the Okinawa Trough

2015 ◽  
Author(s):  
Tomokazu Saruhashi ◽  
Masanori Kyo ◽  
Ikuo Sawada ◽  
Takahiro Yokoyama ◽  
Noriaki Sakurai ◽  
...  
Keyword(s):  
Research And Development ◽  
Deep Sea ◽  
Hydrothermal Vent ◽  
Okinawa Trough ◽  
The Okinawa Trough

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.

Fluctuation of High-Turbidity Water Measured by Acoustic Doppler Current Profiler at the Izena Calderon in the Okinawa Trough

2011 ◽  
Author(s):  
Rei Arai ◽  
Yusuke Onobayashi ◽  
Hiroshi Ishida ◽  
Nobuhiro Maeda ◽  
Tomoya Sugimoto ◽  
...  
Keyword(s):  
Okinawa Trough ◽  
Acoustic Doppler Current Profiler ◽  
Massive Sulfide ◽  
Tectonic Activity ◽  
Time Frequency ◽  
The Okinawa Trough ◽  
Current Profiler ◽  
Adcp Measurements ◽  
High Turbidity ◽  
Hydrothermal Environment

Hydrothermal processes associated with spreading centers of plate-tectonic activity form seafloor massive sulfide (SMS) deposits. Given that the SMS deposits found in the western Pacific have been considered to be potential sources of gold (Au), silver (Ag), cupper (Cu), zinc (Zn), and lead (Pb) including manganese nodules and cobalt-rich manganese crusts, there is a strong possibility that they will be mined in near future. In order to take measures against environmental impact during the mining of SMS deposits, it is important to measure components of hydrothermal origin with high temporal and spatial resolution on site, and to understand the ecosystem in the hydrothermal environment. In this study, we first propose a measurement method of turbidity profiles using an Acoustic Doppler Current Profiler (ADCP). Applying this method to the ADCP measurements in the Izena Calderon with SMS in the Okinawa Trough, we verify that this method can extract turbidity data from echo intensities measured by ADCP. Subsequently, we describe the high-turbidity water in the Izena Calderon measured by ADCP, and present and discuss the turbidity fluctuations estimated by applying time-frequency analysis to these turbidity data.

A new deep water chiton (Mollusca: Polyplacophora) from hydrothermal vent ecosystems in the Okinawa Trough, Japan

Zootaxa ◽  
2018 ◽  
Vol 4531 (3) ◽  
pp. 430
Author(s):  
JULIA D. SIGWART ◽  
CHONG CHEN
Keyword(s):  
Hydrothermal Vent ◽  
Hydrothermal Vents ◽  
Okinawa Trough ◽  
Mitochondrial Gene ◽  
Undescribed Species ◽  
Molecular Barcoding ◽  
The Okinawa Trough ◽  
In Situ Observations ◽  
Morphological Differences

Recent expeditions exploring deep-sea hydrothermal vent ecosystems in the Okinawa Trough, East China Sea resulted in the collection of a hitherto undescribed species of polyplacophoran mollusc found living at three different vent fields at depths of 950–1178 m. This new chiton is a member of the small lepidopleuran family Protochitonidae and is morphologically similar to Hanleyella japonica Saito, 1997. The two species differ in small morphological differences of the valve shape and elevation, are divergent in the standard molecular barcoding mitochondrial gene cytochrome oxidase I (COI), and furthermore the known distribution range of H. japonica is considerably more northern and also shallower. The new species is described herein as Hanleyella henrici n. sp. Additional in situ observations taken in the course of collecting material for this study indicates that chitons are more abundant in the vicinity of hydrothermal vents than was previously appreciated, and perhaps more speciose. 

Dirivultidae (Copepoda: Siphonostomatoida) from hydrothermal vent fields in the Okinawa Trough, North Pacific Ocean, with description of one new species

2020 ◽  
pp. 1-16
Author(s):  
Daisuke Uyeno ◽  
Keiichi Kakui ◽  
Hiromi K. Watanabe ◽  
Yoshihiro Fujiwara
Keyword(s):  
North Pacific ◽  
Hydrothermal Vent ◽  
Okinawa Trough ◽  
North Pacific Ocean ◽  
Filamentous Bacteria ◽  
Adult Males ◽  
Squat Lobster ◽  
The Okinawa Trough ◽  
First Time ◽  
One New Species

Abstract Two species of dirivultid copepod (Siphonostomatoida), Stygiopontius senckenbergi Ivanenko & Ferrari, 2013 and Dirivultus kaiko sp. nov., were discovered from hydrothermal vent fields in the Okinawa Trough, the western North Pacific. Since S. senckenbergi was originally described based on two adult males from the New Ireland Fore-Arc system, Papua New Guinea, the discovery here represents the second record. This species was attached on ventral setae covered with filamentous bacteria of the deep-sea squat lobster Shinkaia crosnieri (Decapoda: Munidopsidae). The female of S. senckenbergi is described for the first time as well as the nauplius I and the copepodid IV. Sexual dimorphism is shown on several appendages (i.e. antennule, leg 2 and leg 5). The nauplius I shows typical lethithotrophic characteristics. Dirivultus kaiko sp. nov., which was found on the tentacular crown of the siboglinid tubeworm Lamellibrachia columna, differs from its two congeners by the antennule, maxilliped and leg 5 of both sexes. These are the second and third dirivultid species to be reported from Japan.

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