A CATCHY TUNA: The United States will support an international ban on the trade of Atlantic bluefin tuna, the Obama administration announced Wednesday, a major turning point in the battle over whether to protect the wildly popular sushi fish. Famed for its rich, buttery taste, bluefin is a sashimi staple in Japan, becoming so popular there and around the world that its population in the Atlantic and the Mediterranean has fallen 74 percent in the last 50 years. Monaco proposed banning bluefin trade last year, a suggestion that sparked debate in Europe and silence in Washington, D.C. The U.S. Interior Department now says it was waiting to see whether international regulators could impose strict enough limits on their own, but has recently concluded that they can't. The United States' heft could help the ban win approval when 175 countries meet in Doha, Qatar, on March 13 to vote on whether trade of the Atlantic bluefin should be banned. "The regulatory mechanisms that have been relied upon have failed to do the job," Assistant Interior Secretary Tom Strickland tells the [skipwords]Washington[/skipwords] Post. "We are literally at a moment where if we don't get this right, we could see this very, very special species really at risk for survival." (Source: Washington Post)

FLIPPER-FLOPPING: After a four-month fishing spree in Oregon, San Francisco's sea lions are apparently going home again. Their disappearance caused some anxiety around the Bay Area — where the barking behemoths have spent decades entertaining tourists at Pier 39 — since they suddenly began disappearing in droves last fall. Their numbers dropped from 1,700 on Oct. 23 to fewer than two dozen by Thanksgiving, just as Oregon's Sea Lion Caves saw its sea lion population skyrocket. Experts say the animals were probably just chasing food, since El Niño helped reduce the Bay Area's herring stocks this year, and anchovies and sardines were plentiful off the Oregon coast. The surprise migration was good for Oregon tourism, which rose up to 20 percent around Sea Lion Caves over the previous winter, but San Francisco will be glad to have its sea lions back. "We're hoping they're coming home," says a spokeswoman for Pier 39, where 80 to 100 sea lions were counted Tuesday. (Source: Oregonian)

THEORY OF DEVOLUTION: The religious battle against teaching evolution is evolving, with Darwin critics increasingly trying to cash in on doubts about climate change by converting them into doubts about science in general, the [skipwords]New York[/skipwords] Times reports. Several states have recently introduced measures that promote teaching "both sides" of issues like the origin of life and the greenhouse effect — a new bill in the Kentucky Legislature, for example, encourages teachers to discuss "the advantages and disadvantages of scientific theories," and Louisiana, Texas, Oklahoma and South Dakota have all launched similar efforts lately. Combining the two issues may help evolution deniers dodge the old "separation of church and state" roadblock, allowing them to argue that they're simply supporting academic freedom rather than trying to erode trust in scientific findings that threaten their religious beliefs. "Wherever there is a battle over evolution now, there is a secondary battle to diminish other hot-button issues like Big Bang and, increasingly, climate change," one physicist tells the Times. "It is all about casting doubt on the veracity of science — to say it is just one view of the world, just another story, no better or more valid than fundamentalism." (Source: New York Times)

INTESTINAL FORTITUDE: There are millions of genes in the human gut, more than the entire rest of the body, and a new study published today in the journal Nature details the bustling complexity of this unseen world for the first time. "Basically, we are a walking bacterial colony," one of the study's authors tells the BBC. "There is a huge diversity. We have about 100 times more microbial genes than human genes in the body." The findings are the first results of an international effort to catalog all the nonhuman genes found in humans, and found that the average person has about 170 different bacteria species operating in the intestinal tract. Studying 124 adults, the researchers detected at least 57 species of bacteria that are present in almost everyone, and overall they found about 1,000 different species. By better understanding the role of gut bacteria, the researchers tell the AP they hope to help develop better medical care for digestive ailments: "This blueprint will allow us to study the role of the flora in many human diseases, such as Crohn's, diabetes, obesity and so on." (Sources: BBC News, Associated Press)

NO. 1 WITH A BULLET: Scientists at Cornell University have discovered a unique way to kill the mosquitoes that spread dengue fever, malaria and other deadly diseases: Make them hold their urine. Mosquitoes normally relieve themselves while drinking blood, part of an intricate flight plan that makes them light enough to quickly escape before they're swatted. Urinating while feeding also prevents salt and fluid overloads that can kill a mosquito, and now Cornell researchers have identified a key protein in the insects' kidneys that may let them stop mosquitoes from spreading both yellow showers and yellow fever. "Too much weight will impair the mosquito's flight performance, like an aircraft with too much payload," says one of the researchers. "Thus, blocking the function of this protein in natural populations of mosquitoes may limit their ability to survive the physiological stresses of a blood meal and to further transmit viruses." The Cornell research is in the same vein as other recent efforts to hack mosquitoes' genes, such as releasing sterile male mosquitoes into the wild, or releasing genetically engineered females that are incapable of flying. (Source: e! Science News)

Russell McLendon

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Photo (bluefin tuna): ZUMA Press

Photo (San Francisco sea lions): Jeff Chiu/AP

Image (Charles Darwin): ZUMA Press

Photo (Enterococcus faecalis bacteria): genome.gov

Photo (mosquitoes): Northwest Mosquito Abatement District/AP

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.