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In the December issue of Arctic, a photographer and an arctic biologist note that there have now been three documented sightings of adult male polar bears on sea ice feeding on younger bear kills. The waxy buildup in a whale's ears may contain interesting data about its exposure to contaminants.

Nature has evolved efficient strategies to synthesize complex mineralized structures that exhibit exceptional damage tolerance. One such example is found in the hypermineralized hammer-like dactyl clubs of the stomatopods, a group of highly aggressive marine crustaceans. The dactyl clubs from one species, Odontodactylus scyllarus, exhibit an impressive set of characteristics adapted for surviving high-velocity impacts on the heavily mineralized prey on which they feed. Consisting of a multiphase composite of oriented crystalline hydroxyapatite and amorphous calcium phosphate and carbonate, in conjunction with a highly expanded helicoidal organization of the fibrillar chitinous organic matrix, these structures display several effective lines of defense against catastrophic failure during repetitive high-energy loading events.

"USC researcher experiments with changing ocean chemistry Jan. 19, 2011 | Molly Peterson | KPCC In his lab, USC's Dave Hutchins is simulating possible future atmospheres and temperatures for the Earth. He says he's trying to figure out how tiny organisms that form the base of the food web will react to a more carbon-intense ocean. Burning fossil fuels doesn't just put more carbon into the atmosphere and help warm the climate. It's also changing the chemistry of sea water. KPCC's Molly Peterson visits a University of Southern California researcher who studies the consequences of a more corrosive ocean. Tailpipes and refineries and smokestacks as far as the eye can see in Los Angeles symbolize the way people change the planet's climate. They remind Dave Hutchins that the ocean's changing too. Hutchins teaches marine biology at USC. He says about a third of all the carbon, or CO2, that people have pushed into earth's atmosphere ends up in sea water - "which is a good thing for us because if the ocean hadn't taken up that CO2 the greenhouse effect would be far more advanced than it is." He smiles. Hutchins says that carbon is probably not so good for the ocean. "The more carbon dioxide that enters the ocean the more acidic the ocean gets." On the pH scale, smaller numbers represent more acidity. The Monterey Bay Aquarium Research Institute estimates we've pumped 500 million tons of carbon into the world's oceans. Dave Hutchins at USC says that carbon has already lowered the pH value for sea water. "By the end of this century we are going to have increased the amount of acid in the ocean by maybe 200 percent over natural pre-industrial levels," he says. "So we are driving the chemistry of the ocean into new territory - into areas that it has never seen." Hutchins is one of dozens of scientists who study the ripples of that new chemistry into the marine ecosystem. Now for an aside. I make bubbly water at home with a soda machine, and to do that, I pump ca