Marine wildlife at all levels of the food chain has been badly damaged by human activity, reveals new study that urges immediate and “meaningful rehabilitation” if we are to avert mass extinction in the world’s oceans.
“We may be sitting on a precipice of a major extinction event,” Dr. Douglas J. McCauley, an ecologist at the University of California, Santa Barbara and an author of the study, told the New York Times.
Over the past 500 years, approximately 500 land-based animal species have become extinct as a result of human activity. In the ocean, where scientists count only 15 or so such losses, the numbers currently aren’t nearly as dire.
But that doesn’t mean they aren’t yet heading in that direction.
In the new study, a consortium of scientists led by Dr. McCauley found that the same patterns that led to the collapse of wildlife populations on land are now occurring in the sea. According to the researchers, wildlife populations in the oceans are as healthy as those on land were hundreds or thousands of years ago. However, they warn, that may be about to change as the next 100 years promise to present major challenges to marine life. Their findings are published in the journal Science.
The new paper compares the march of the Industrial Revolution on land to current patterns of human use of the world’s oceans. During the 1800s vast tracts of farmland and factories beat back forests and sucked up resources that were mined and drilled out of the ground. As a result, many terrestrial species were driven to extinction. In the ocean, however, fishing continued to rely on sailing ships clustered in small slivers of near-shore water.
“A lot has changed in the last 200 years,” said Dr. McCauley. “Our tackle box has industrialized.”
Growing threats to marine life
Unsustainable fishing is the principal threat to marine life today, according to the study, but the ocean life faces a number of dangers. The study’s authors say the great whale species, while no longer being hunted on a wide scale, face hazards that include noise pollution and oil exploration. Bottom trawling, an industrial fishing method that can alter marine habitats, can also put species at risk.
“There are factory farms in the sea and cattle-ranch-style feed lots for tuna,” said co-author Dr. Steve Palumbi of Stanford University, describing the emerging threats to ocean life. “Shrimp farms are eating up mangroves with an appetite akin to that of terrestrial farming, which consumed native prairies and forest.”
The development of coastal cities and a practice known as “seasteading,” or building artificial lands in the ocean — with one such example being the United Arab Emirates famous construction of artificial islands off the coast of Dubai — also present problems to marine habitats, along with seafloor mining and oil and gas extraction.
“All signs indicate that we may be initiating a marine industrial revolution,” said Dr. McAuley. “We are setting ourselves up in the oceans to replay the process of wildlife Armageddon that we engineered on land.”
Immediate action could fend off mass extinction
One solution the paper highlighted involves setting aside more and larger areas of the ocean that are safe from industrial development and fishing. However, co-author Dr. Robert Warner, an EEMB research professor at UCSB, cautioned that reserves alone are not enough. “We need creative and effective policy to manage damage inflicted upon ocean wildlife in the vast spaces between marine protected areas,” he said.
Among the most serious threats to ocean wildlife is climate change, which according to the scientists is degrading marine wildlife habitats and has a greater impact on these animals than it does on terrestrial fauna. “Anyone that has ever kept a fish tank knows that if you crank up your aquarium heater and dump acid into the water, your fish are in trouble,” said co-author Dr. Malin Pinsky, an ecologist at Rutgers University. “This is what climate change is doing now to the oceans.”
Unfortunately, recent evidence demonstrates that we’re heading in the wrong direction when it comes to climate change. According to an analysis released yesterday by NASA and the National Oceanic and Atmospheric Association, 2014 was officially the hottest year in recorded history.
Still, as the researchers emphasized, the relative health of the oceans presents an opportunity for saving them. “Because there have been so many fewer extinctions in the oceans, we still have the raw ingredients needed for recovery,” said Dr. McCauley. “There is hope for marine species that simply does not exist for the hundreds of terrestrial wildlife species that have already crossed the extinction threshold.”
The ocean’s future is yet to be determined, the researchers said. “We can blunder forward and make the same mistakes in the sea that we made on land,” said Dr. Warner, “or we can collectively chart a different and better future for our oceans.”