Supersized Crabs Sound Tasty But They’re Really Bad News

The very words “supersized crabs” may have you reaching for the gumbo pot, but not so fast. At first blush, a bigger and better crab sounds like the one good thing that can come from oceans polluted by carbon and other emissions that pour out of factories and into our oceans. Crabs eat carbon, and more carbon does mean a bigger crab.

However, marine scientist Justin Baker Ries, who has studied the crabs in the threatened Chesapeake Bay, said that the super crabs hit the seafood chef with a one-two punch.

First of all, they eat oysters, and the bigger crabs can eat many more of them. That prevents vulnerable oyster beds from rebounding even after humans have poured millions of dollars into oyster bed restoration efforts.

Second, the supersized crabs themselves still have the same weight in meat as the smaller crabs. That’s right. They’re gaining all the size in their inedible shells.


The Chesapeake Bay, the nation’s largest estuary, is expected to continue to suffer from the effects of too much carbon, which spurs the growth of the crabs while forcing oysters to grow more slowly, for as long as another century.

Clearly, that’s a problem, as it might be possible for the ever-growing supersized crabs to eat the oysters to near-extinction and then suffer a population crash of their own, destroying the seafood market for both foods.

Ries has been studying the problem for years. According to his research, if you’ve noticed that shrimp and lobsters seem to be getting bigger, that isn’t your imagination either. Those two crustaceans seem to get the same jolt from carbon pollution that the crabs do.

Meanwhile, oysters and scallops struggle. Their shells are actually thinner as a result of the pollution, so the bigger, stronger crabs have easier prey to crack into.

Sometimes a cloud really doesn’t have a silver lining. Who knew that a supersized crab could have a dark side?

[crab photo by Jeff Kovac and the Food Group via Flickr and Creative Commons]