Crabs are bulking up on carbon pollution that pours out of power plants, factories and vehicles and settles in the oceans, turning the tough crustaceans into even more fearsome predators. That presents a major problem where crabs eat oysters. In a life-isn’t-fair twist, the same carbon that crabs absorb to grow bigger stymies the development of oysters.
Higher levels of carbon in the ocean are causing oysters to grow slower, and their predators — such as blue crabs — to grow faster. Over the next 75 to 100 years, ocean acidification could supersize blue crabs, which may then eat more oysters and other organisms and possibly throw the food chain of the nation’s largest estuary out of whack.
That would undermine an effort to rebuild the stocks of both creatures. Lobsters and shrimp also are bulking up on carbon dioxide along the Atlantic coast. Like oysters, coral that helps protect small organisms from big predators is being adversely affected by higher acidity in the waters.
Crabs put away carbon like nobody’s business. The more they eat, the faster they molt, a growth spurt during which their shells go soft. Carbon helps speed the process so that they emerge bigger and perhaps stronger, less vulnerable to predators and more formidable predators themselves. At UNC, marine geologists are analyzing video of the slaughter that took place when they put mud crabs and oysters in tanks they intentionally polluted with carbon over three months for a 2011 study.
It was like watching lions tear apart lambs. The crabs scurried from their side of the tanks, banged on the shells of the traumatized oysters, pried them open with a claw in a way similar to what humans do with a knife at restaurants and gobbled them down. For crab lovers, bigger doesn’t necessarily mean better. Carbon-absorbing crabs put all their energy into upgrading shells, not flesh — like a mansion without much furniture. So diners might be disappointed years from now when they crack open huge crabs and find little meat.
Crabs, lobsters and shrimp grew bigger more rapidly as carbon pollution increased. Blue crabs grew nearly four times faster in high-carbon tanks than in low-carbon tanks.
But under the same conditions, oysters, scallops and other organisms struggle to grow, making them more vulnerable to carnivores. Oysters in high-carbon tanks grew at only one-quarter the speed they did in low-carbon conditions, according to the study.
Crabs growing faster with carbon pollution in ocean
The blue crab is so named because of its sapphire-tinted claws. Its shell, or carapace, is actually a mottled brownish color, and mature females have red highlights on the tips of their pincers.
Prized by humans for their sweet, tender meat, these wide-ranging, ten-legged crustaceans are among the most heavily harvested creatures on the planet. Their scientific name, Callinectes sapidus, means "savory beautiful swimmer."
Blue crabs are found in brackish coastal lagoons and estuaries from Nova Scotia, through the Gulf of Mexico, and as far south as Uruguay. Close relatives of the shrimp and lobster, these bottom-dwelling omnivores have a prickly disposition and are quick to use their sharp front pincers. Large males can reach 9 inches (23 centimeters) in shell width.
They feed on almost anything they can get hold of, including mussels, snails, fish, plants, and even carrion and smaller blue crabs. They are also excellent swimmers, with specially adapted hind appendages shaped like paddles.
Blue crabs are extremely sensitive to environmental and habitat changes, and many populations, particularly in the Chesapeake Bay in the eastern United States, have experienced severe declines. Blue crabs also play a key role in managing the populations of the animals they prey on, and constant overharvesting has had wide-ranging negative effects on the ecosystems they inhabit. For this reason, comprehensive management schemes are in place in several parts of the blue crab's range.
With a razor sharp and super bright 5" Full HD Reality Display, Mobile BRAVIA Engine 2, a 13 megapixel camera with Exmor RS™ for mobile - the world's first image sensor with HDR video for smartphones and a sleek design that resists both water and dust, Xperia Z combines the best of Sony in a smartphone. The Xperia sports a glass back panel and sealed chassis with a soft-touch plastic “skeleton frame” around the edge. In a world of big black slabs, it is the ultimate big black slab. It’s also water and dust resistant, which is something that’s still rare to find on Western phones. The Sony Xperia Z offers a tried-and-true Android button setup similar to that of Google’s Nexus devices -- back, home and task-switching keys as part of the screen. That gives you single-tap access to multitasking, and means you can quickly activate Google Now via the swipe-up shortcut. Earlier handsets such as the Sony Xperia S and Sony Xperia T were extremely promising from a brand striking out on its own - but it's with the Xperia Z that Sony is really banking on making a cataclysmic dent in the makeup of the smartphone market.
If you're coming from something like a Samsung Galaxy S3, it'll feel similar, if a little larger, in terms of size: the Sony Xperia Z rocks in at 139 x 71 x 7.9mm/5.47 x 2.79 x 0.31 inches, so there's little room for anything else in your hands. Coming from something smaller like, say, an iPhone 5, you'll certainly notice the difference. But it's amazing how quickly you'll adapt. At 146g/5.15oz, it's by no means the lightest handset out there - but the Sony Xperia Z exudes a heftiness that belies a quality device. It's on a par with Apple's offering when it comes to the thickness.
The ports are spread out with the headphone jack up top, the SIM slot and volume rocker on the right - either side of a silver standby button - while both the microSD and charging ports are on the left, alongside contacts for accessories. A watertight port covers each. The front of the Sony Xperia Z is minimalist - showing off only a Sony logo and front-facing camera. The rear is a little busier, with various tech info printed on it, plus the Sony Xperia logo, an NFC badge, camera light and the all-important lens. That back is stuck fast - as is becoming the custom, you'll have no luck if you want to remove the battery.
One of the selling points of the Sony Xperia Z is that it is also water resistant. There's something slightly unnerving about taking a £529 (around US$817/AU$789) phone and dropping it in the sink - but that's exactly what we did. And it worked absolutely fine. Clearly, you'll need to make sure the ports are covered using those watertight protectors, that much goes without saying.
A screen so immersive you can get lost in it, images so real you feel like you're there, and a camera that lets you capture the moment whenever and wherever it occurs. See how Xperia Z takes you to new places and lets you connect in totally new ways: