Black Smokers

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Newby found a video showing a black smoker in the Juan de Fuca ridge system near Vancouver Island.

http://www.youtube.com/watch?v=bCWsQ9OAc24&feature=player_detailpage

During the expeditions of the Nautilus many here have been watching the ROV Herkules exploring some black smokers in the Mediteranian Sea. So i thought I´d try to portrait them in a post.

Lost City hdrothermal field on the Mid Atlantic Ridge.

The first black smoker was found 1977 by the famous submarine ALVIN when Robert Ballard used it to explore the seafloor near the Galapagos Islands. Subheated water over 400 °C hot, also very acidic emerged from natural chimneys in around 2000 meter depth. Hydrothermal vents, found at an average depth of 7,000 feet, are shrouded in total darkness. Toxic chemicals, extreme water pressure and temperature dictated boundaries all combine to produce a problematic habitat. And yet despite this intimidating description, they support a surprisingly wide variety of marine life. This discovery came as a total suprise, if not even as a shock to scientists. Before mankind had been thinking that the deep oceans, where sunlight does not reach anymore, are pretty lifeless. Now it was found that those vents harbour many life forms and millions of creatures are a result of chemosynthetic bacteria.

At the very base of the food chain bacteria-like organisms called archaea that use a process called chemosynthesis to turn chemicals from the vents into energy. By creating energy, these archaea provide the basis for all life within the hydrothermal vent habitat.

The bacteria use hydrogene sulfid to produce energy. They grow in thick mats on which creatures like amphipods and copepods graze directly.
A biological community is formed and animals like snails, shrimp, crabs, tube worms, fish, and octopuses are on top of this food chain.
Later a new form of photosynthesis was discovered around a Black Smoker in the deep sea before Mexcio. Chlorobiaceae is a form of bacteria who can use the faint glow emerging from the hydrothermal vent for photosynthesis. Beforehand people had been thinking, only sunlight can be used for this procedure. Another variety of those hydrolthermal vents are called “White Smokers”. The name results in the lighter colour of the emitted minerals such as Barium, Calcium and Silicon at a lower temperature. The chimneys Black Smokers build often consist of Anhydrite first and later the sulfides of Zinc Copper and Iron are added. Some chimneys have been found to grow up to 30 cm a day!

Black smokers have been discovered in every ocean, the ones farther north 73 degrees between Norway and Greenland go by a very romantic name “Loki’s Castle“. The world’s deepest black smokers explored so far are located in the Cayman Trough, around 5000 m  below sea level. Many of those vents have really inventive names like Losts City or Medusa hydrothermal vent field  ( Costa Rica) or Magic Mountain ( west of Vancouver Island Canada) or Endevaour Hydrothermal Vents ( southwest of Vancouver Island Canada)  or even Godzilla.

Distribution of chemicals around a hydrothermal vent.

One of the most astounding creatures that have been discovered close to hydrothermal vents on the seafloor are giant tube worms. Those creature extent to a length of up to 4 meters and are one of the fastest growing species on earth. And they sure need to be able to grow that fast. Such black smoker systems often only exist for some decades. An earthquake or even a submarine volcanic eruption might change the habitat and life has to start again, in another spot on the seafloor. What also suprised the scientist … when a submarine ditched down on a tube worm accidently, it was suddenly surrounded by a red liquid. When this was studied later, people found that this liquid is very similar to human blood!

BBC Wildlife in the Oceans.
Giant Tube Worms.

Prior to the scientists understanding the role played by archaea it has been thought that the deep sea creatures lived solely off marine snow slowly decending to the seafloor. But now, in the light of this new information, a dramtically different hypothesis has been published. Now scientists think it possible that all life on earth has  evolved from hydrothermal vents in the ocean. This opens new possibilties for life outside the earth. It is considered possible, that Jupiters moon Europa might have such vents in its ocean below its ice cover. But going there, finding those vents and exploring them wont be easy and will cost lots of money. If life on earth emerged from hdrotherml vents… this opens a whole new set of options within our solar system and also within the universe.

A number of Hydrothermal vents have led to the formation of exploitable mineral resources via deposition of seafloor massive sulfide deposits. Recent rises in the price of base metals have attracted mineral exploration companies who are turning their attention to extraction of mineral resources from the seafloor. This has the potential for disasterous consequenses for these habitats.   Within a relatively short period of time the environmental impacts would include dust plumes from mining machinery affecting filter feeding organisms, collapsing or reopening vents, methane clathrate release, or even sub-oceanic landslides.

A final point, for the last twenty years the conservation of hydrothermal vents has been the subject of frequent heated discussion within the Oceanographic Community. The ecosystem is considered particularly vulnerable to light intrusion and it has been pointed out that, prior to the possible commencement of mineral mining,  those that are currently causing serious damage to this rare and fascinating habitat are scientists. Despite attempts to reach an understanding governing their behaviour when investigating vent sites, and although there is an agreed code of practice there is, as yet, no formal international and legally binding agreement.

If you check for “Hydrothermal Vent” on Youtube you will find lots of videos.
I linked some for you:
BBC page
Aukland Museum movie on hydrothermal vents.
David Attemborough on Hydrothermal Vents.
NOAA Ship Okeanos Explorer: Galápagos Rift, New Hydrothermal Vent 

Spica and Kilgharrah.

Update: Link to MESA: Deep Sea Biology, Questions and answers about hydrothermal vents 

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