SANTA BARBARA, Calif. — The violet bottom-dwelling, prickle-backed spheres wriggling in the tank in Gretchen Hofmann’s lab aren’t really known for their speed.

But these lowly sea urchins adapt so quickly they’re helping answer a question that’s key to understanding ocean acidification:

As fossil-fuel emissions disrupt marine life, will evolution come to the rescue?

Like Darwin’s finches or Great Britain’s peppered moths, these hedgehogs of the sea increasingly embody nature’s stunning capacity for resilience.

A number of plants and animals threatened by souring seas, including some mussels, abalone, rock oysters, plankton and even a few fish, appear likely — at least at first — to adjust or evolve. But few seem as wired as these saltwater pincushions to come through the next several decades unscathed.

Yet work with urchins, as well as other species, suggests that acidification sooner or later may still push these and other marine organisms beyond what they can tolerate.

“Evolution can happen, and it can happen quickly,” said Hofmann, a marine biologist at the University of California, Santa Barbara (UCSB), who has studied urchins for years. “But concerns about extinctions are very real and very valid. Biology can bend, but eventually it will break.”

The oceans are absorbing a quarter of the carbon dioxide emitted by burning coal, oil and natural gas. That, researchers say, is causing sea chemistry to change faster than it has for tens of millions of years.

Which plants and animals can accommodate these more corrosive seas — and for how long — will depend on many factors, from where they live to their population sizes to the depth of stress they face from other forces, such as warming temperatures and pollution. Survival will vary species by species. Not everything will make it.

“This kind of change is not free; evolution is not a gentle sport,” said Stephen Palumbi, an evolutionary ecologist at Stanford University, who also works extensively with urchins. “When evolution happens, it’s because the unfit are dying. It’s pretty brutal.”

And that’s when things work well.

From : Seattle Times

Categories: Climate Change, Ocean acidification, Scientific Adventure

Tags: Gretchen Hofmann, marine biologist, ocean acidification