Hydrothermal vents

hydrothermal vents

1. Hydrothermal Vents Sangamesh V Mathad MSc – I D ept of M arine Science Goa University

2. O bjectives To understand hydrothermal vents, its unique ecology, distribution and also about threats its being faced

3. A hydrothermal vent is a fissure in a planet's surface from which geothermally heated water issues . Common land types include hot springs  and geysers. These commonly found near volcanically active places, areas where tectonic plates are moving. Some of the submarine hydrothermal vents hosts complex communities fueled by the chemicals dissolved in the vent fluids. Hydrothermal Vents

4. Structure

5. Hydrothermal vent Ecology The water from the hydrothermal vent is rich in dissolved minerals and supports a large population. Bacteria use sulfur compounds, particularly hydrogen sulfide, to produce organic material through the process of  chemosynthesis. Larger organisms, such as snails, shrimp, crabs, tube worms, fish (especially eelpout, cutthroat eel,  ophidiiforms  and  Symphurus thermophilus ), and octopi (notably  Vulcanoctopus hydrothermalis ), form a food chain of predator and prey relationships above the primary consumers. The main families of organisms found around seafloor vents are annelids,  pogonophorans , gastropods, and  crustaceans.

6. Distribution

7. Black S mokers Theory Günter Wächtershäuser  proposed the iron-sulfur world theory and suggested that life might have originated at hydrothermal vents. It has been proposed that amino acid synthesis could have occurred deep in the Earth's crust and that these amino acids were subsequently shot up along with hydrothermal fluids into cooler waters, where lower temperatures and the presence of clay minerals would have fostered the formation of peptides and  protocells . A major limitation to this hypothesis is the lack of stability of organic molecules at high temperatures, but some have suggested that life would have originated outside of the zones of highest temperature

8. Deep sea mining Many hydrothermal vents are rich in cobalt, gold, copper, and rare earth metals essential for electronic component. Nautilus Minerals  - newly constructed mining ship in the territorial waters of Papua New Guinea. Nautilus Minerals, in partnership with Placer Dome (now part of  Barrick Gold), succeeded in 2006 in returning over 10 metric tons of mined SMS to the surface using modified drum cutters mounted on an ROV. Neptune Minerals is at an earlier stage. Near  Kermadec Islands in the South Pacific Ocean 800–1,000 km (500–620 mi) northeast of New Zealand's North Island.

9. Case study: First Hydrothermal Vent Communities from the Indian Ocean Discovered Jun Hashimoto, Suguru Ohta , Toshitaka Gamo , Hitoshi Chiba , Toshiyuki Yamaguchi , Shinji Tsuchida , Takamoto Okudaira , Hajime Watabe , Toshiro Yamanaka and Mitsuko Kitazawa ABSTRACT —Thriving chemosynthetic communities were located for the first time in the Indian Ocean between 2420 and 2450 m, on a volcanic knoll at the eastern crest of an axial valley, approximately 22 km north of the Rodriguez Triple Junction. The communities were distributed in a 40m by 80m field around the knoll. At least seven active vent sites, including black smoker complexes that were emitting superheated water at 360°C, were observed at the field. The faunal composition of the Indian Ocean hydrothermal vent communities had links to both Pacific and Atlantic vent assemblages. This discovery supports the hypothesis that there is significant communication between vent faunas in the Pacific and Atlantic Oceans via active ridges in the Indian Ocean.

10. Measuring the temperature of an active black smoker by the ROV Kaiko at the Kairei Field. The temperature of superheated water was 360°C at maximum.

11. Results and discussions On August 25, 2000, the Kaiko successfully located the first active hydrothermal site in the Indian Ocean . Twenty species of vent-specific organisms were collected within and near the Kairei Field, and additional six species were observed.

12. Communities were dominated by swarms of densely packed shrimp belonging to the genus Rimicaris and crowded beds of actinians belonging to the family Actinostolidae . This is similar in appearance to the Atlantic vent sites , Rimicaris had been previously reported only from the Atlantic Ocean. However, the iphitimidid polychaete , Ophryotrocha , the provannid gastropod Alviniconcha , the bythograeid crab Austinograea , and the scalepellid cirriped Neolepas , known previously only from the Pacific Ocean ,were found and captured at the Kairei Field. Shells, but no live individuals, of the vesicomyid clam were also observed close to the Kairei Field. The clams and other vent organisms observed including actinostolid actinians , Branchipolynoe polynoids , Lepetodrilus limpets, Phymorhynchus gastropods, Bathymodiolus mussels, Chorocaris shrimp and Munidopsis galatheids were reported from both Atlantic and Pacific hydrothermal vent sites .

13. R efrences First Hydrothermal Vent Communities from the Indian Ocean Discovered, Author(s): Jun Hashimoto, Suguru Ohta , Toshitaka Gamo , Hitoshi Chiba, Toshiyuki Yamaguchi, Shinji Tsuchida , Takamoto Okudaira , Hajime Watabe , Toshiro Yamanaka, and Mitsuko Kitazawa. Published By: Zoological Society of Japan (2001) An obligately photosynthetic bacterial anaerobe from a deep-sea hydrothermal vent J. Thomas Beatty,  Jörg Overmann , Michael T. Lince , Ann K. Manske , Andrew S. Lang, Robert E. Blankenship,Cindy L. Van Dover, Tracey A. Martinson, and F. Gerald Plumley Proc Natl Acad Sci U S A. 2005 Jun 28. Published online Oceanography by S avinder Singh, page 234