Scientists have been worried about coral reefs for years, since realizing that rising temperatures and rising ocean acidity are hard on organisms that build their skeletons from calcium carbonate. Researchers on Australia's Great Barrier Reef are conducting an experiment that demonstrates just how much corals could suffer in the coming decades.

Stanford scientists have discovered that some purple sea urchins living along the coast of California and Oregon have the surprising ability to rapidly evolve in acidic ocean water -- a capacity that may come in handy as climate change increases ocean acidity. This capacity depends on high levels of genetic variation that allow urchins' healthy growth in water with high carbon dioxide levels.

The study, co-authored by Stephen Palumbi, a senior fellow at the Stanford Woods Institute for the Environment and director of Stanford's Hopkins Marine Station, revealspreviously unknown adaptive variations that could help some marine species survive in future acidified seas.

It is the dawn of the super crab.

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 for the Chesapeake Bay, 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,” Justin Baker Ries, a marine geologist at the University of North Carolina’s Aquarium Research Center, said in an recent interview.

Ocean acidification, which occurs as CO₂ is absorbed by the world's oceans, is a source of concern for marine scientists worldwide. Studies on coral, mollusks, and other ocean denizens are helping to paint a picture of what the future might entail for specific species, should carbon emissions continue to increase.

In a new study published in Global Change Biology, University of Miami (UM) Rosenstiel School of Marine & Atmospheric Science researchers Sean Bignami, Su Sponaugle, and Robert Cowen are the first to study the effects of acidification on the larvae of cobia (Rachycentron canandum). Cobia are large tropical fish that spawn in pelagic waters, highly mobile as they mature, and a popular species among recreational anglers.

Slip beneath the water's surface and you'll find a world teeming with life. Schools of yellowtail fish dart through colorful coral reefs. Spiny lobsters emerge from the crevices of ocean rocks searching for a tasty meal. And sea anemones nestle in the nooks of oyster beds.

Scientists are learning more about how carbon dioxide is dramatically changing the makeup of the oceans and the communities that depend on them.