Deep-sea vents Ocean-floor migration
How surface winds blow deep-sea critters from vent to vent
EVER since their discovery in the 1970s, deep-sea ventschimney-like structures on the ocean floor that belch hot water and dissolved minerals into the surrounding oceanhave been one of the hottest topics in marine biology. The vents support populations of bacteria, giant worms, clams, shrimp and other creatures in the inky darkness, often several kilometres below the surface. Unlike virtually every other ecosystem on the planet, these deep-sea communities do not rely on the sun for their food. Instead of using photosynthesis, the bacteria at the bottom of the food chain harvest energy from chemicals supplied by the vents themselves.
The vents are both widely spaced and transient, which means their denizens live a precarious existence. Yet travel between vent systems is apparently possible, even across miles of desolate ocean floor. Creatures confined to islands rapidly head in a different genetic direction to mainland relatives; but researchers have found surprisingly little genetic variation between the populations of even quite widely spaced ocean-bottom vents. Last year one paper described how a vent system that had been wiped clean by a volcanic eruption was quickly recolonised by a variety of larval creatures, some of which seemed to have travelled from another vent more than 300km away. Exactly how has remained a mystery.
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2016-02-26
2016-02-26
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