At An Underwater Volcano, Evidence Of Man's Environmental Impact

Scientists studying hydrothermal vents, those underwater geysers that are home to bizarre geological structures and unique marine species, have discovered something all too familiar: pollution.

A University of Florida geologist is among a team of geologists that is the first to observe “anthropogenic influence” in hydrothermal deposits, according to an article in the June issue of the journal Marine Geology. Examining deposits retrieved from the site of an underwater volcano near Italy, they discovered lead that did not come from the underlying rocks or from any possible natural source in the nearby region or anywhere in Europe.

Instead, they traced the lead to an Australian lead mine thousands of miles away.

“I guess we can speculate that this is yet another piece of evidence of how widespread our disturbance in the environment is: the fact that we can influence natural hydrothermal systems,” said George Kamenov, a faculty member at the UF geological sciences department.

Hydrothermal vents form when seawater seeps through cracks in the deep ocean floor, gets heated by magma, or molten rock, then streams upward back into the sea. The vents have aroused a great deal of scientific interest since they were discovered in 1977, in part because of their remarkable appearance but mainly because they host unusual creatures and offer natural laboratories to study the formation of metal ores. Some have tall and elaborate “chimneys” formed from minerals disbursed by the hot water as it leaves the ocean floor. “Black smokers,” the hottest hydrothermal vents, spew dark-looking iron and sulfide particles as they shoot up through seawater. Found throughout the world’s oceans, many vents even harbor eyeless shrimp, giant clams and other fauna rarely seen elsewhere.

At An Underwater Volcano, Evidence Of Man's Environmental Impact