Biogeography of Deep-Water Chemosynthetic Ecosystems
Encyclopedia
The Biogeography of Deep-Water Chemosynthetic Ecosystems is a field project of the Census of Marine Life
Census of Marine Life
The Census of Marine Life was a global network of researchers in more than 80 nations engaged in a 10-year scientific initiative to assess and explain the diversity, distribution, and abundance of life in the oceans...

 programme (CoML). The main aim of ChEss is to determine the biogeography
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...

 of deep-water chemosynthetic ecosystems
Deep sea communities
Deep sea communities currently remain largely unexplored, due the technological and logististical challenges and expense involved in visiting these remote biomes. Because of the unique challenges , it was long believed that little life existed in this hostile environment...

 at a global scale and to understand the processes driving these ecosystems. ChEss addresses the main questions of CoML on diversity, abundance and distribution of marine species, focusing on deep-water reducing environments such as hydrothermal vent
Hydrothermal vent
A hydrothermal vent is a fissure in a planet's surface from which geothermally heated water issues. Hydrothermal vents are commonly found near volcanically active places, areas where tectonic plates are moving apart, ocean basins, and hotspots. Hydrothermal vents exist because the earth is both...

s, cold seep
Cold seep
A cold seep is an area of the ocean floor where hydrogen sulfide, methane and other hydrocarbon-rich fluid seepage occurs, often in the form of a brine pool...

s, whale fall
Whale fall
Whale fall is the term used for a whale carcass that has fallen to the ocean floor. Whale falls were first observed in the 1980s, with the advent of deep-sea robotic exploration....

s, sunken wood and areas of low oxygen that intersect with continental margin
Continental margin
The continental margin is the zone of the ocean floor that separates the thin oceanic crust from thick continental crust. Continental margins constitute about 28% of the oceanic area....

s and seamount
Seamount
A seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface , and thus is not an island. These are typically formed from extinct volcanoes, that rise abruptly and are usually found rising from a seafloor of depth. They are defined by oceanographers as...

s.

Background

Deep-sea hydrothermal vents and their associated fauna were first discovered along the Galapagos Rift in the eastern Pacific in 1977. Vents are now known to occur along all active mid ocean ridges and back-arc spreading centres, from fast to ultra-slow spreading ridges. The interest in chemosynthetic environments was strengthened by the discovery of chemosynthetic-based fauna at cold seeps along the base of the Florida Escarpment in 1983. Cold seeps occur along active and passive continental margins. More recently, the study of chemosynthtetic fauna has extended to the communities that develop in other reducing habitats such as whale falls, sunken wood and areas of oxygen minima when they intersect with the margin or seamounts.
Since the first discovery of hydrothermal vents, more than 600 species have been described from vents and seeps. This is equivalent of 1 new description every 2 weeks(!). As biologists, geochemists, and physicists combine research efforts in these systems, new species will certainly be discovered. Moreover, because of the extreme conditions of the vent and seep habitat, certain species may have specific physiological adaptations with interesting results for the biochemical and medical industry.

These globally distributed, ephemeral and insular habitats that support endemic faunas offer natural laboratories for studies on dispersal, isolation and evolution. Here, hydrographic and topographic controls on biodiversity and biogeography might be much more readily resolved than in systems where climate and human activity obscure their role. In addition, hydrothermal vents have been suggested to be the habitat of the origin of life. These hypotheses are being used by ChEss researchers in collaboration with NASA to develop programmes to search for life in planets or moons of the outer space.

Objectives of ChEss

Only a small fraction of the global ridge system (~65000km) and of the vast continental margin regions have been explored and their communities described. It is the aim of ChEss to improve the knowledge on the diversity, abundance and distribution of species from vents, seeps and other reducing habitats at a global scale, understanding their the abiotic and biotic
Biotic
Biotic is a living component of a community; for example organisms, such as plants and animals.Biotic may also refer to:*Life, the condition of living organisms,*Biology, the study of life,*Biotic material, which is derived from living organisms,...

 processes that shape and maintain these ecosystems and their biogeography.

Main ChEss Science Questions
  • I. What are the species' relationships between different habitats: vents, seeps, whale falls, sunken wood and OMZs?
  • II. What is the role of deep-water circulation and geographical barriers in gene flow and biogeography?
  • III. What are the factors driving patterns of biodiversity in these habitats?


Objective 1. To create a centralised database

To create a centralised database, ChEssBase, of deep-water vent, cold seep, whalefall and OMZ species. ChEssBase is a web-based database that incorporates archived and newly collected biological material. The database is geo- and bio-referenced. ChEssBase is available online and has been integrated with OBIS.

Objective 2. To develop a long-term field programme

To develop a long-term field programme to locate potential vent and seep sites and continue research on whalefalls and OMZ sites. The field programme aims to explain the main gaps in our knowledge of the diversity, abundance and distribution of chemosynthetic species globally. A limited number of target areas have been selected where specific scientific questions relevant to biogeographical issues will be answered.

The target areas have been grouped into two categories. Category I, combined areas: Area A: Equatorial Atlantic Belt region; Area B: the SE Pacific region; Area C: NZ region; Area D: the Arctic and Antarctic regions, within the International Polar Year. Category II, specific areas: 1 – The ice-covered Gakkel Ridge, 2 – the (ultra)-slow ridges of the Norwegian-Greenland Sea, 3- the northern MAR between the Iceland and Azores hot-spots; 4 – the Brazilian continental margin, 5 – the East Scotia Ridge and Bransfield Strait, 6 – the SW Indian Ridge, 7 – the Central Indian Ridge.
During the field programme, ChEss will promote the development and refinement of deep-towed, remotely operated (ROV
Rov
Rov is a Talmudic concept which means the majority.It is based on the passage in Exodus 23;2: "after the majority to wrest" , which in Rabbinic interpretation means, that you shall accept things as the majority....

) and autonomous underwater (AUV) vehicle technologies to locate, map and sample new chemosynthetic systems. Using optical, chemical and acoustic techniques, ChEss researchers hope to gain a better understanding of not only biogeographical patterns, but to determine the processes driving these ecosystems.

During the field programme, ChEss will promote the development and refinement of deep-towed, remotely operated (ROV) and autonomous underwater (AUV) vehicle technologies to locate, map and sample new chemosynthetic systems. Using optical, chemical and acoustic techniques, ChEss researchers hope to gain a better understanding of not only biogeographical patterns, but to determine the processes driving these ecosystems.

Objective 3: Outreach and Education

ChEss has multi-lingual education pages related to vents, seeps and whalefalls. There is a dedicated page for key outreach initiatives such as live cruise diaries, open days, schools activities etc.

ChEss has joined forces with the other deep-sea CoML projects and this has resulted in the creation of the DEep-Sea Education and Outreach group (DESEO) that has produced a book “Deeper than Light” published in 5 languages.

External links

  • ChEss Website
  • http://www.scor-int.org/Project_Summit_3/CoML_Input.pdf
  • http://www.biologiezentrum.at/biophp/de/band_det.php?litnr=23702
  • http://www.tos.org/oceanography/issues/issue_archive/20_1.html
  • http://www.blackwell-synergy.com/toc/mae/28/1
  • http://www.noc.soton.ac.uk/chess/science/sci_publications.php
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK