Marine species cut in half in just four decades

Discovery News - In just four decades, marine species have declined by 49 percent, according to one of the most extensive surveys of marine life ever compiled.

The “Living Blue Planet Report,” just released by World Wildlife Fund in collaboration with the Zoological Society of London, documents the extraordinary losses, which occurred from 1970 to 2012. Alarmingly, some fish species were found to have declined by almost 75 percent.

The authors of the report attribute the dramatic population drops to human-driven climate change as well as to habitat loss, over-exploitation and pollution.

“In less than a human generation, we can see dramatic losses in ocean wildlife -- they have declined by half -- and their habitats have been degraded and destroyed,” Brad Ack, senior vice president for Oceans at WWF, told Discovery News. “Driving all these trends are humans actions: from over-fishing and resource depletion, to coastal development and pollution, to the greenhouse gas emissions causing ocean acidification and warming.”

The findings were determined after researchers surveyed more than 10,000 populations of 3,038 marine species, including fish, birds, mammals and reptiles. The report estimates that close to one-third of the world’s fish stocks are over-fished, and 1 in 4 species of sharks, rays and skates are threatened with extinction.