"SLIME HIGHWAY": The Gulf of Mexico's sea floor is covered for miles with a "fluffy and porous" layer of oil, scientists discovered Sunday night and Monday morning, and it's beyond anything produced by natural oil seeps. "I've collected literally hundreds of sediment cores from the Gulf of Mexico, including around this area," says University of Georgia marine scientist Samantha Joye. "And I've never seen anything like this." The oily fluff is more than 2 inches thick in some places, and in addition to being studded with tiny tar balls, it has also trapped a menagerie of dead shrimp, worms and other invertebrates. "It's kind of like having a blizzard where the snow comes in and covers everything," Joye tells the AP. These new findings back up an earlier study by scientists at the University of South Florida, who reported in August that oily sediment had collected on the seabed off the Florida Panhandle. Part of the reason for this "slime highway," as Joye describes it, is that oil-eating microbes excrete mucus, which eventually becomes heavy and sinks, taking oil down with it. But the chemical dispersants used by BP may have also played a role, as well as the Gulf's warm water temperatures, both of which helped speed up the breakdown of oil. That could also now become a problem, however, since colder water near the sea floor may slow down the oily slime from degrading further. Chemical tests later in the week are still required to prove definitively that this slime is a product of the Gulf oil spill, rather than from natural seeps, but Joye has little doubt. "It has to be a recent event," she says. "There's still pieces of warm bodies there." (Sources: Associated Press, MSNBC, NPR, New York Times)

WALRUS WOES: A remote beach in northwest Alaska is the setting for a bizarre and troubling scene: Tens of thousands of walruses are lounging on land rather than their usual sea ice, which has mostly vanished this summer amid record-high temperatures. The mass of tusks and blubber is occupying about a mile of beach near Point Lay, Alaska, with the animals "packed shoulder-to-shoulder," a U.S. Geological Survey biologist tells the AP. While this is odd behavior for walruses, it's not unprecedented; similar phenomena occurred in 2007 and 2009, when Arctic sea ice was similarly hovering around record-low levels. Aside from foreshadowing the effects of global warming, the congregation could pose an immediate threat to the walruses' health, scientists say, since the one-ton animals are easily spooked and prone to stampede — potentially crushing each other, especially smaller calves. That's why federal officials are working to change airplane flight patterns to prevent engine noise from scaring the herd, and are asking locals to be prudent about hunting them. But the greater overall threat is that sea ice will likely be harder and harder to find as the Arctic heats up, forcing the walruses to "commute" from land when they're hungry for fish. "We suspect it will have real change in the cost of making a living for the walrus," a USGS researcher tells Alaska Dispatch. "Instead of rolling off the ice and having your food right there, they might have to commute." And as the director of the National Snow and Ice Data Center tells the AP, walruses had better get used to the lifestyle of long-distance commuting. "We'll likely see more summers like this," he says. "There is no sign of Arctic recovery." (Sources: AP, Alaska Dispatch)

SPLASH AND BURN: Swimming in chlorinated pools can trigger permanent mutations of a person's DNA, according to a new study by Spanish scientists, and may raise the swimmer's risk of developing cancer. Studying a group of healthy subjects who swam in an indoor pool treated with chlorine, the researchers from Barcelona's Center of Research in Environmental Epidemiology found several indicators of increased cancer risk, as well as the potential for respiratory ailments. "The evidence of genotoxic effects were observed in 49 healthy adults after swimming for 40 minutes in a chlorinated indoor pool," the center said in a statement released Monday. Chlorine is commonly added to swimming pools to disinfect them, and the researchers say the danger is primarily due to compounds produced by reactions between the disinfectants and organic matter from swimmers, such as sweat, skin cells and urine. Still, despite this discovery, the researchers say they don't want to discourage people from taking a dip. "The positive health impacts of swimming can be increased by reducing the levels of these chemicals," the center's co-director tells AFP. "In no case do we want to stop swimming, but to encourage the reduction of chemicals in swimming pools." (Sources: United Press International, Agence France-Presse)

THINK FAST: Action-packed, shoot-'em-up video games like "Call of Duty 2" and "Unreal Tournament" aren't just mindless time-wasters, according to a new study published in the journal Current Biology — in fact, they can actually help people make good decisions faster in real life. Cognitive scientists from the University of Rochester tested dozens of 18- to 25-year-olds who don't normally play video games, splitting them into two groups who spent 50 hours playing two different types of games. One group busied themselves with two fast-paced action games, "Call of Duty 2" and "Unreal Tournament," while the other group delved into the slower, more strategy-based "The Sims 2." Afterward, all the test subjects were asked to make quick decisions in a range of visual tasks designed by the researchers, such as glancing at a screen and determining whether more dots in a group were moving to the left or to the right. They were then given a set of auditory tasks to make sure the effects weren't just limited to visual perception. The subjects who had been playing action video games were up to 25 percent faster in answering, the study found, and their answers were correct just as often as those who'd been playing the slower-paced game. "It's not the case that the action game players are trigger-happy and less accurate: They are just as accurate and also faster," says one of the study's co-authors. "Action game players make more correct decisions per unit time. If you are a surgeon or you are in the middle of a battlefield, that can make all the difference." (Source: ScienceDaily)

Russell McLendon

Want to receive the day's eco-news in your inbox? Click here to sign up for the Daily Briefing newsletter.

Photo (oil layer in Gulf sediment core): AP/Samantha Joye, UGA

Photo (walruses on shore near Point Lay, Alaska): AP/USGS

Photo (man swimming): Getty Images Digital Vision

Photo (people playing video games): Jupiter Images

The opinions expressed by MNN Bloggers and those providing comments are theirs alone, and do not reflect the opinions of MNN.com. While we have reviewed their content to make sure it complies with our Terms and Conditions, MNN is not responsible for the accuracy of any of their information.