Here’s some bad news for fans of tuna and mackerel

September 16, 2015, 9:26 PM UTC
South China Sea
A Filipino fisherman is seen past the US Navy amphibious transport dock ship USS Green Bay (LPD-20) during an amphibious landing exercise on a beach at San Antonio in Zambales province on April 21, 2015, as part of annual Philippine-US joint maneuvers some 220 kilometres (137 miles) east of the Scarborough Shoal in the South China Sea. The Philippines voiced alarm April 20 about Chinese "aggressiveness" in disputed regional waters as it launched giant war games with the United States that were partly aimed as a warning shot to Beijing. AFP PHOTO/TED ALJIBE (Photo credit should read TED ALJIBE/AFP/Getty Images)
Photo by Ted Aljibe—AFP/Getty Images

It’s a tough time if you’re a fan of fish.

Populations of the world’s tuna and mackerel have dipped to dangerous levels in recent years, a new report says.

In fact, the amount of fish swimming globally has more than halved since 1970, according to the WWF conservation group. Reuters notes that over-fishing and other issues have decimated fish stocks. For instance, the amount of tuna and mackerel has decreased by as much as 75%.

“There is a massive, massive decrease in species which are critical” for the planet, Marco Lambertini, director general of WWF International, told Reuters. “The ocean is resilient but there is a limit.”

“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, told the news wire. “This is a terrible and dangerous legacy to leave to our grandchildren.”

As Reuters notes:

World marine fish catches dipped to 79.7 million tonnes in 2012 from 82.6 million in 2011, according to the U.N.’s Food and Agriculture Organization. Safeguarding the oceans can help economic growth, curb poverty and raise food security, it says.