The Next Great Extinction Crisis Is Under Way Under the Sea

Overfishing, pollution, and climate change have contributed to a devastating decline in marine life.

Manta ray. (Photo: Getty Images)

Sep 16, 2015· 1 MIN READ
Taylor Hill is an associate editor at TakePart covering environment and wildlife.

Imagine the outcry if half the life on land had disappeared over the past 45 years.

That’s what has happened in the world’s oceans, according to a new report that finds that global populations of marine species have plummeted 49 percent since 1970.

Certain fish that people rely on for food suffered even steeper declines: Populations of tuna, bonito, and mackerel dropped by 74 percent, according to the study, which was compiled by the World Wildlife Fund and reviewed by researchers at the Zoological Society of London.

By compiling data from 2,337 individual sources, including population estimates from scientific studies and databases, the researchers were able to estimate the changes in species populations from 1970 to 2012.

The scientists attributed the marine population crash to overfishing, habitat destruction, and climate change. In other words, the blame lies with us.

“This is catastrophic,” Louise Heaps, chief adviser on marine policy at WWF U.K., told The Guardian. “We are destroying vital food sources and the ecology of our oceans.”

The report found that shark finning and industrial fishing have decimated shark and ray populations, with one in four species now threatened by extinction.

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Other species suffering major declines include sea cucumbers, a luxury food item in Asia. Populations have fallen by 98 percent in the Galápagos and by 94 percent in the Egyptian Red Sea.

Sea cucumber. (Photo: Jeff Rotman/Getty Images)

The researchers linked industrial pollution and plastic contamination of the oceans with the degradation of marine habitats and the death of endangered sea turtles and other wildlife. The burning of fossil fuels is accelerating the acidification of the oceans, destroying coral reefs that sustain a plethora of fisheries as well as 400 million people.

The world’s coral reefs, which support 25 percent of marine species, could be wiped out if ocean temperatures continue to rise at their current rate, according to a 2011 report from the World Resources Institute.

“This report spells a lot of bad news, however, the good news is there are opportunities for world leaders to turn things around,” Brad Ack, senior vice president for oceans at WWF, said in an email.

Ack said nations need to shut down illegal fishing operations; protect remaining coral reefs, mangroves, and other critical marine habitat from development; and agree on cuts in greenhouse gas emissions at the Paris climate conference in December.

“The ocean is a renewable resource that can provide for all future generations if the pressures are dealt with effectively,” Marco Lambertini, director general of WWF International, said in a statement. “If we live within sustainable limits, the ocean will contribute to food security, livelihoods, economies and our natural systems.”

Illegal gill nets snare baby sharks near the Galápagos Islands. (Photo: Tui De Roy/Getty Images)