You think you got lucky plucking out those giant, supersized crabs from the ocean. Think again. Those oh-so-delicious crabs didn't get to that size because they were healthy. They got big thanks to the carbon dioxide (CO2) and other toxic emissions that come out of the world's too many power plants, factories and vehicles that settle in the ocean.

And while these crabs seem to thrive in the rising CO2, the same could not be said of the oysters.

"Higher levels of carbon in the ocean are causing oysters to grow slower, and their predators - such as blue crabs - to grow faster," Justin Baker Ries, a marine scientist from the Aquarium Research Center of the University of North Carolina, said.

According to a Science World report, increased levels of CO2 in the oceans automatically spell doom for oysters and corals because more acidic waters make these creatures to form shells more slowly, thus making them vulnerable to predators like crabs and lobsters.

Suffice to say, the abnormal predator-prey relationship currently ongoing between the two could lead to a multimillion problem to the global oyster industry.

Crab-meat lovers are also warned that the supersizing goes only shell-deep. The apparent supersizing does not translate to more crab-meat.

"They still have the same weight in meat as the smaller crabs. They're gaining all the size in their inedible shells," Mr Ries said.

Unless radically altered, the world's growing CO2 level would contribute to further ocean acidification, which over the next 75 to 100 years could supersize blue crabs. Bigger crabs would then gobble up more oysters and other organisms under the ocean.

Mr Ries not only crabs are getting supersized, but also shrimp and lobsters.

On the opposite, apart from oysters, scallops have been seen to struggle. Their shells have been thinned out due to the pollution, thus easier for the bigger, stronger crabs to crack into.

A 2009 research published in the Geology journal had showed that crustaceans, such as Chesapeake's blue crabs, grew four times faster in high-carbon tanks compared with those placed in low-carbon tanks.

While oysters exposed to same high-carbon conditions grew only at one-quarter the speed of those in low-carbon tanks.