The Hydrothermal Vent (What Lives There)

By Matthew Geldman

Generally when ask to to picture the ocean, most of us imagine a vast blue body of water, bright clear lagoons or even coral reefs that are teaming with life.  However there is more than what you can see, there is the deep dark. Light  under the right conditions can travel to about 1000 meters. Yet this rarely happens, and light from the surface usually reaches 200 meters, this is because light participle, photons, are either reflected back to space by the ocean surface, are absorbed by phytoplankton for photosynthesis or adsorbed/deflected by other participles in the ocean.

The different levers of the ocean. source
The different levers of the ocean. source

Light is is unable to penetrate past 1000 meter depth and this part of the Ocean in known as the Bathypelagic or the  Midnight zone. Deeper that  we get the Abyssopelagic  zone here there is absolutely no light. The pressure here is around 40 MPa and the temperature ranges between 2 – 4°C

How Can Life Live Down Here?

Polystyrene cup crushed at 4800m depth. Source
Polystyrene cup crushed at 4800m depth. Source

How can life survive in this extreme habitat, Abyssopelagic  zone, where there is no light where the pressure can crush a polystyrene 38% of their original size and the temperature is always between  2 – 4°C. Well quoting Dr. Ian Malcolm (Jeff Goldblum) from Jurassic park; “Life Finds A Way”. 

In the case of the deeps sea Abyssopelagic  zone, the way  is that of the hydrothemal vents. Hydrothemal vents are found along  mid-ocean ridges, these includes the Mid-Atlantic ridge, Southwest Indian Ridge, Central Indian Ridge,Southeast Indian Ridge, the Pacific Antarctic Ridge, The East Pacific Rise and the Juan de Fuca Ridge. For this blog I’ll be looking at the Mid Atlantic Ridge and the organisms found there. Underwater volcanoes cause the tectonic plates to spread apart along the ridges and convergent plate boundaries produce hot springs known as hydrothermal vents. The sea water seeps in to the ground and gets super heated mixing with the chemicals in the magma. This super heated water bellows  out of the vent as black plumes, these water contain hydrogen sulphide.

Mid Ocean Ridges found around the world. Source
Mid Ocean Ridges found around the world. Source

 

 Hydrothemal vents of the Mid Atlantic Ridge.

First the hydrothemal vents need to be located, this involves dragging a CTD, conductivity, temperature, and depth measuring instrument, 100- 400 m above the ocean floor.  the sensors locate dispersing  non-buoyant hydrothermal plumes. This creates a high resolution map of the ocean floor.

To visit the hydrothermal vents a Deep Sea Research Vessel (DSRV) also known as Alvin is deployed, Alvin can travel down to the depth need to see what lives at the deepest parts of our ocean.

alvin_dsv-2
The Alvin DSRV
So what species can survive in there toxic super heated water?:

One such animal is the Giant tube worms, Riftia pachyptila. The giant tube worm has a number adaptations in order to survive in this extreme environment. The main function of  its body is for gas-exchange, anchorage and support, and the acquisition of nutrients. However the Giant tube worms gains most of its nutrients form a special symbiotic bacteria.  The  intracellular sulfur-oxidizing  symbiotic bacterium oxidize reduced inorganic sulfur compounds to obtain energy and reducing power for autotrophic carbon fixation. It converts the chemicals in the water  into organic material that can be used by the tube worm for nourishment.

Giant tube worm
Giant tube worm
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