This was the worst extinction event ever to hit the planet

Jan 7, 2012 10:56 GMT  ·  By
Mercury is extremely damaging to the environment, and may have played a role in the Great Dying
   Mercury is extremely damaging to the environment, and may have played a role in the Great Dying

The Permian–Triassic (P-Tr) extinction event was the worst mass dying to affect life in all history. It occurred about 250 million years ago, and scientists thought they had a pretty good idea of the factors that caused it. Yet, a new study managed to identify a culprit that also played a role in the extinction.

The new investigation was carried out by experts at the University of Calgary and Natural Resources Canada, and sought to identify less-known or previously-unknown factors that also influenced the event. Informally, the P-Tr extinction is known as the Great Dying.

Only a small fraction of sea and land animals survived. Entire groups of species disappeared without a trace, never to recover again. In fact, this was the only extinction ever to affect insects, which were notoriously resilient to the other 4 major extinctions.

One of the most interesting things the team discovered was that the ecosystem suffered a massive influx of mercury during that interval. Granted, this couldn't have triggered the extinction all by itself, but it didn't help, either.

“No one had ever looked to see if mercury was a potential culprit. This was a time of the greatest volcanic activity in Earth's history and we know today that the largest source of mercury comes from volcanic eruptions,” Dr. Steve Grasby explains.

“We estimate that the mercury released then could have been up to 30 times greater than today's volcanic activity, making the event truly catastrophic,” adds the expert, who holds an appointment as a research scientist at the NRC, and is also an adjunct professor at the University of Calgary.

He is a coauthor of a new paper detailing the role of mercury in the Great Dying. The work is published in this month's issue of the esteemed scientific journal Geology. University of Calgary professor of geology Dr. Benoit Beauchamp was also a coauthor of the study.

“Geologists, including myself should be taking notes and taking another look at the other five big extinction events,” Beauchamp says. He adds that this is one of the first studies ever to look at the link between mercury and an extinction event.

The amount of mercury that made its way into the ecosystem must have been huge, since even the capture and storage power of algae was exceeded by a wide margin. “In this case, the load was just so huge that it could not stop the damage,” says Dr Hamed Sanei, the lead author of the paper.

The investigation also raises an alarm for the present. Mercury levels in the environment are rising slowly, but steadily, and we need to be vigilant about just how much of the stuff we let accumulate, SpaceRef reports.