



More than just snuffing out more than 5,000 mantas a year, this trade also threatens diving tourism for local economies. The conservation group Shark Savers puts the value that manta rays generate in terms of the tourism they attract at $140 million a year, which would make each manta ray worth more than $1 million over its lifetime.

That tug-of-war is underway in Mozambique. The black market for manta rays that has encouraged rampant plundering may soon threaten the country's tourism -- one of its main industries -- since its mantas are a major diving attraction. One of Mozambique top diving areas, Inhambane, has one of the world's biggest manta populations. And in the last 10 years, the manta's numbers there have thinned by 87 percent, say scientists.

"We're looking at decimation in the next decade or decade-and-a-half. Manta rays are in big trouble along the coastline," Andrea Marshall, director of the Marine Megafauna Foundation, told the Guardian. "If current trends continue, I don't give this population more than a few generations."

It's the same for sharks, which when viewed as tourism industry assets, can be worth as much as $2 million each, and, in aggregate, generate hundreds of millions of dollars for local economies annually . Shark-diving is now an attraction in more than 40 countries worldwide.

And that's not just hurting sharks, totoaba and manta rays -- China's black market for fish parts is probably messing up marine ecosystems. Shark finning, for instance, is removing one of the main predators. The unexpected consequences that arise when a species is knocked out of an ecosystem are called trophic cascades.

For instance, as North Atlantic sharks have been killed off, the populations of their prey have grown. And since that prey typically eat coastal bivalves, those have become increasingly scarce. That, among other things, caused a North Carolina scallop fishery to shutter in 2004, and has driven up the cost of clam chowder such that fewer and fewer restaurants in the U.S northeast still serve it. (Note, though, that trophic cascades tend to be incredibly complicated, meaning that the causal relationships are poorly understood. That means that one effect of shark-finning was an oversimplification of the marine ecosystem that "villainized" the cownose ray, resulting in the "Save the Bay, Eat a Ray" campaign -- and now that population could eventually be at risk of being overharvested ).

China is dramatically under-reporting what it's taking from the world's seas. The average it told the UN Food and Agriculture Organization over the last decade was 368,000 tons each year. A recent European Parliament report puts that number at 4.6 million tons -- some 12.5 times more than what China reported. Here's a look at that, with the waters where it says it's "landing" fish:

China's "landing" of fish, with waters it says it's fishing in on the left, and the accumulated reports of foreign governments on the right."China's distant-water fisheries in the 21st century," Fish and Fisheries, 2012

By far the biggest focus of its extraction is Africa, bringing in 3.1 million tonnes a year from African waters -- and up to 2.5 million tonnes of that is likely to be illegal. Here's a look at the geographic breakdown: