Marine science: Boiling points

In Bangladesh, arsenic is being reduced, by microbial activity, from As(V) in the sediment to the more soluble As(III), which seeps into the groundwater and contaminates the drinking water. Jan Amend, a microbial geochemist at Washington University in St Louis, hopes that his team's work at the Ambitle vents will help researchers better understand how microbes might catalyse the reverse chemical reaction, oxidizing As(III) back into the less soluble As(V). "This part of the arsenic cycle has not received nearly as much attention," he says.

Before Rachel Haymon sailed to the Galapagos Islands last December, a fellow oceanographer made her a bet on whether she would find a particular kind of hydrothermal vent. The Galapagos region is where scientists discovered these vents, underwater fissures where superheated water bubbles out of the sea floor. But one of the most dramatic vent phenomena -- black smokers, chimneys that spew a flood of dark mineral particles -- had never been seen in the area.

According to some, this was because the geological setting of the Galapagos should not permit the formation of black smokers. But in retrospect, Haymon says, she should have upped the ante on her bet. On 14 December her team discovered the first Galapagos black smoker.

And that isn't the only new find. In the past couple of years, marine scientists have discovered numerous vents. What was once a handful of isolated vents has expanded into a dizzying diversity of oceanic wonders. Researchers don't yet know what to make of all the finds, but for now they are sitting back and enjoying the feast.

The recent finds include the most northerly active high-temperature chimneys in cold Arctic waters; chimneys in the South Atlantic; and the biggest plume ever recorded of hydrothermal chemicals released from an underwater eruption. With each new discovery, marine scientists are realizing that the unusual is to be expected. Variations in geology, chemistry, physics and biology make every vent field unique.

•	Marine science: Boiling points Teams of researchers are finding vents in ocean floors around the globe Nature.com, Wednesday, Feb. 22, 2006 Byline: Christina Reed