New study finds humans on the verge of wiping out sea life


Ian Lang, National Monitor 

The rate of human destruction is on the rise, but scientists say it’s not too late.

Most people are well aware by now that the human impact on Earth’s ecosystems is rarely positive. But what about the oceans, those vast, unyielding expanses of biodiversity? A new study lead by researchers from multiple institutions finds that not only are humans having an effect, but we’re much closer to causing large-scale extinctions than anyone previously thought.

The (somewhat) good news is that compared to the havoc wreaked on dry land, the oceans aren’t unsalvageable. Their size, diversity and the adaptability of the life within them make restoration possible, provided the right actions are taken.

“We’re lucky in many ways,” said Malin L. Pinsky, a marine biologist at Rutgers University and a co-author of the new report. “The impacts are accelerating, but they’re not so bad we can’t reverse them.”

The problem with evaluating the health of ocean ecosystems is scale: Oceans are epic in the literal sense of the word, and accurately tracking the well-being of species across tens of thousands of miles can be daunting. To get a better idea of the big picture, UC Santa Barbara ecologist Douglas J. McCauley and others aggregated data from multiple sources, everything from the fossil record to modern commercial fishing statistics. The data may be old, but what they revealed when viewed together was revelatory.

Though overfishing continues to be a problem, wide-scale loss of habitat is a more pressing concern. For more adaptable species, they’ve been able to move to cooler or warmer waters as called for by their biology. Unfortunately, not all species are so lucky.

Regardless of adaptability, chemistry is making life difficult for all marine life. Building carbon emissions, themselves a problem for land-dwellers, is making the oceans more acidic. As one researcher put it, were you to dump some acid in your fish tank and raise the temperature, you wouldn’t be surprised if your goldfish didn’t take it so well.

Other human activity plays a role as well. Fish farms are built in existing fragile ecosystems. Whales have dodged the bullet of mass-hunting, but now die in collisions with ever-increasing shipping traffic. Seabed mining, literally non-existent just 15 years ago, now covers 460,000 square miles of the ocean floor.

“If by the end of the century we’re not off the business-as-usual curve we are now, I honestly feel there’s not much hope for normal ecosystems in the ocean,” said Stephen R. Palumbi of Stanford University. “But in the meantime, we do have a chance to do what we can. We have a couple decades more than we thought we had, so let’s please not waste it.”

If there’s any good news, it’s just that humans aren’t cut out to be ocean predators.

“Fundamentally, we’re a terrestrial predator,” said Dr. McCauley. “It’s hard for an ape to drive something in the ocean extinct.”


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