Impending Disaster: Marine Species Face Mass Extinction, Experts Say

Species threatened by rising temperatures, fishing.

ByABC News
June 21, 2011, 11:12 AM

June 22, 2011— -- Marine experts are now prophesying a perfect storm: a world where marine species could undergo unprecedented levels of extinction.

"The speed of change, particularly related to climate change is so great there simply isn't time for marine life to adapt to these new conditions," said Alex Rogers, a professor of conservation biology at the University of Oxford. "When we've seen mass extinctions in the past they've been associated with large disturbances in the carbon system of the oceans. That's what we're bringing about through our own actions today."

Earlier this year Rogers and 26 other researchers from six countries met for a three-day workshop in England to examine ocean stressors, such as overfishing. This week the panel of marine experts released a summary report from Oxford University -- and the full report is on the way. Their findings? A disturbing decline in the health of the ocean that is on track to get much worse.

Multiple factors, such as acidification of the ocean, rising ocean temperature and overfishing are contributing to the rapid decline of some species, such as reef-forming coral. Rogers, lead author of the International Programme on the State of the Ocean (IPSO) report, says other species, such as sharks, may follow.

"In the Mediterranean nearly 50 percent of sharks are under threat of extinction in that region," Rogers told ABCNews.com.

The significance of the scientists' meeting, Rogers explained, was to gather experts from different branches of marine biology and figure out how negative changes to the ocean are interacting with one another.

In some cases, the impacts canceled each other out, but Rogers said, "In many cases we found the impacts were negatively synergistic – this means that when the effects are taken together, the overall effect is greater than the single effect."

The best example of this, he explained, is the coral reef ecosystems. Overfishing and bleaching of the reefs, combined with the acidification that causes the corals to bleach, means the loss of "the most diverse marine ecosystems on the planet."

And one of the most valuable, Rogers pointed out. The coral reefs provide tourism, coastal protection and living environments for marine species.

But the idea that ocean stressors could lead to a new globally significant "extinction event" is not the same as a prediction, cautioned Jesse Ausubel, director of the Program for the Human Environment at The Rockefeller University in New York City.

The IPSO report, he said, is "plausibly putting together a lot of really terrible things that could happen. I don't disagree with it."

But, he said, "They don't attach probabilities to anything."

"Take the example of ocean acidification – what has actually happened is very small so far," Ausubel told ABCNews.com. "It could be a very serious problem in say 100 years -- it might be in 40 to 50 years."

The authors may be "comprehensive worriers," according to Ausubel, but he found the panel's report well-written and useful.

"I was struck that they also pointed to the renewable energy resources as a stressor on ocean life -- and they're right," he said, referring to tidal turbines and offshore windmills.