AN IDLE MINE: Decades after they were shut down, as many as 2,000 mercury mines still dot the coastal mountains of central California, silently seeping the toxic heavy metal into the state's major waterways. It's making fish dangerous to eat — especially for the 100,000 or so poor people and immigrants who subsist on the region's marine life — but, according to a new AP investigation, the U.S. government has tried to clean up just 10 mines, and even those cleanups have largely failed to stop the contamination. California was the nation's top mercury-producing state during the last two centuries, much of it being used for gold mining in the Sierra Nevada. Mercury, a potent neurotoxin, is most dangerous when passed up the food chain via fish, since it both takes the deadlier form of methylmercury and accumulates to stronger concentrations as it moves up from plankton to people. It can permanently damage the brain, especially in children and fetuses. Regulators call mercury the "most harmful invisible pollutant" in California's watershed, adding that it will take a long time to solve the problem. "It took a hundred years to occur," says one EPA official. "And it may take a hundred years or more to solve." (Source: Associated Press)

 

IN FARM'S WAY: You don't have to live in central California to be surrounded by dangerous drinking water. In the latest edition of the NY Times' "Toxic Waters" series, the paper takes a front-page look at the problem of farm runoff contaminating groundwater, which feeds many rural residents' well water. Farmers frequently spray manure over their fields as fertilizer, which may seem like a reasonable way to use the ridiculous amounts of manure a farmer often ends up with. But when that fertilizer is spread too thick, the E. coli and other bacteria it contains can seep slowly into underground aquifers, eventually finding their way to residential wells. The EPA has drafted special rules to deal with large, concentrated animal farms' waste runoff, but many farmers never file their paperwork, and others dodge regulation thanks to Bush-era standards allowing them to self-certify. Agricultural runoff is the single largest source of inland U.S. water pollution, according to the EPA, sickening an estimated 19.5 million Americans annually. (Source: New York Times)

 

CROP SHOP: The new White House-area farmers market opened Thursday, graced by the presence of first lady Michelle Obama, who addressed the 300 shoppers in attendance before shopping for produce herself. "I have never seen so many people so excited about fruits and vegetables," Obama said before buying cheese, fingerling potatoes, eggs and organic Tuscan kale. She is believed to have had a hand in organizing the market, which helps highlight her overall push for healthier food choices and draws even more attention to her already-popular White House vegetable garden. "The first thing world leaders, prime ministers, kings, queens ask me about is the White House garden," she said Thursday. "And then they ask about Bo." (Sources: Huffington Post, Washington Post)

 

WRITING IS ON THE WALRUS: Federal wildlife officials have discovered up to 200 dead walruses lying on Alaska's northwestern coastline, and while the cause of death is unknown, it's likely that climate change is at least an accomplice. Young walruses can be crushed when a herd is startled by a polar bear, human hunters or low-flying airplanes, and walruses are now increasingly forced to congregate in large on-shore groups as the Arctic warms up and sea ice melts down. They normally perch on floating sea ice, diving below briefly to hunt for clams, but have recently been noticed in huge clusters on beaches — about 3,500 were reported in one group last week on Alaska's Icy Cape. Scientists plan to investigate the mass die-off once weather allows them to land a plane nearby. (Source: AP)

 

CHEETAHS NEVER WIN: Cheetahs have been hunted to extinction in 15 different countries, and the dwindling African and Asian populations of the fleet-footed big cats are now suffering genetic weaknesses from inbreeding. India is one of the species' former homelands — it's where it earned its name, citrakaya in Sanskrit — and at least one Indian official is launching a controversial effort to bring cheetahs back to the country. "The only mammal to go extinct since independence in India is [the] cheetah," Minister of Environment and Forests Jairam Ramesh said during a recent Parliamentary meeting. "We plan to bring the cheetah back." There are hurdles, however: Cheetahs need large tracts of open space for hunting, something officials are reluctant to give up in the fast-growing nation, and Asian cheetahs are also hard to come by. Iran has already turned down India's request for one of its 100 Asian cheetahs, leaving India to shop for African cheetahs in Kenya, Namibia or South Africa. (Source: Scientific American)

 

DINOSAUR JR.: Scientists have discovered a tiny ancestor of the most iconic dinosaur that ever lived: the Tyrannosaurus rex. Dubbed the "Raptorex," it was only 10 feet tall and 150 pounds — about 100 times smaller than a typical T-rex — but was nearly identical in anatomy. It even has the puny forearms, which proves that T-rex wasn't short-armed to offset its heavier body weight, but rather as a tradeoff for speed and agility while running upright. The new fossil is 125 million years old and came 85 million years before T. rex grew to its famous size, which scientists say probably happened once competing predators became extinct. The discovery was nearly missed, as it was dug up illegally and sold on the Chinese black market — fortunately to a fossil collector who recognized its scientific importance. (Sources: CNN, Agence France-Presse)

 

— Russell McLendon