'Supersized' Crabs Could Threaten Ocean Ecosystems Worldwide

 @ericbrownzzz
on April 09 2013 7:56 PM

 

Brace yourself, because the supersized crabs are coming, and they could do huge amounts of damage to the ecosystems they inhabit. 

Thanks to speeding ocean acidification, an effect of rising carbon being burned into the atmosphere, crabs are growing at alarming rates, sometimes up to four times faster and larger than normal, reports the Washington Post. This leads to larger, "supersized" crabs that could threaten ecosystems.

Researches from the University of North Carolina’s Aquarium Research Center spoke to the Post about their findings, stating that  ocean acidification could lead to more carbon in the water, which speeds up development in crabs, creating larger, hungrier, supersized creatures that pose a danger to oysters and other prey in waters like the Chesapeake Bay. 

"Higher levels of carbon in the ocean are causing oysters to grow slower, and their predators — such as blue crabs — to grow faster," UNC marine biologist Justin Baker Ries told the Washington Post.

At the UNC Aquarium Research Center, researchers placed mud crabs and oysters in an intentionally polluted tank containing extreme levels of carbon. According to a 2009 study in Geology, crabs grew up to four times faster in the polluted, high-carbon tanks. As the supersized crabs reached maturity, they began eating oysters at alarming rates.

At a glance, larger crabs might seem like a good thing. After all, a supersized crab means more meat, right? Wrong. In reality, supersized crabs are a net loss all around. When crabs absorb more oxygen than normal, they focus all their energy on bulking up their shells, not their muscles. 

To put it simply, not only do the supersized crabs actually have less meat than their smaller brethren, the supersized crabs are much hungrier than normal crabs and consume oysters at a greatly increased rate. And when you take into account that the same conditions which create supersized crabs cause oysters to grow smaller and slower, you have a huge ecological imbalance on your hands. 

“It’s taking them longer to go from oyster spat to oyster adult,” Luke Dodd, a doctoral candidate at UNC, told the Post. “When you’re a baby, there’s tons of predators that want to eat you up.”

The reports of supersized crabs come at a particularly bad time for Chesapeake Bay oysters as well. Overfishing has been a serious threat to their numbers for decades, and two diseases known as Dermo and MSX have wiped out thousands of bushels of oysters each year. While a recent report from the Washington Post suggests that the oyster population may be rebounding, oyster levels are still far below what they were a century ago. 

If supersized crabs really are as great a threat as UNC scientists believe, Chesapeake Bay oysters could soon be on the downswing again, leading to higher prices and inferior seafood all around. 

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