Global fish stocks drop 50 percent: Have oceans passed a point of no return?

Researchers say that climate change and overfishing have contributed to the massive decline in the world's marine life in the past 40 years.

First Look

The number of fish swimming in the world's oceans has declined by nearly half in just 40 years.

That's according to a recent report by the environmental advocacy group WWF, which found that amount of fish in the ocean has decreased by 49 percent since 1970.

The environmental advocacy organization's Living Blue Planet Report uses a marine planet index to track 5,829 populations of 1,234 species. The species in the index were analyzed by the Zoological Society of London (ZSL) and include a variety of mammals, birds, reptiles, and fish.

"This report suggests that billions of animals have been lost from the world's oceans in my lifetime alone," Ken Norris, director of science at the ZSL, said in a statement. "This is a terrible and dangerous legacy to leave to our grandchildren."

Researchers at WWF and ZSL analyzing the troubling evidence blame overfishing and climate change for the population plunge.

Mismanagement is pushing “the ocean to the brink of collapse,” Marco Lambertini, the director general of WWF International told Reuters. "The ocean is resilient but there is a limit."

"There is a massive, massive decrease in species which are critical," both for maintaining ocean ecosystems and feeding billions of people adds Mr. Lambertini.

Some commercial fish species, such as tuna, mackerel, and bonito, have fallen by almost 75 percent, according to the study. The report authors argue that the world’s fishing fleets have been too big, and unnecessarily encouraged by subsidies totally $14-35 billion a year.

Although it may hurt economies in the short term, decreasing world marine catches will actually raise food security and encourage economic growth in the long term.

Popular habitats, such as coral reefs and mangroves, have been damaged by human presence and climate change, adding to problems led by over-fishing. Other problems include climate change raising water temperatures and making the oceans more acidic, as well as heavy pollution from increased coastal development.  

But is it too late to save the world's marine life? 

WWF insists that progress is possible, but “To reverse the downward trend we need to preserve the oceans natural capital; produce better; consume more wisely; and ensure sustainable financing and governance.”

An example are the revived fisheries of Fiji, proving that stronger surveillance of illegal fishing gives stocks a chance to recover. According to the United Nation’s Food and Agricultural Organization, world marine catches dropped from 82.6 million tons in 2011 to 79.7 million tons in 2012.

Later this month, governments will discuss new UN sustainable development goals, including destruction from over-fishing and illegal practices. Their goal will be to end destructive practices by 2020 and restore stocks "in the shortest time feasible." 

This report contains material from Reuters.