Choppy seas prevailed in the northern Gulf of Mexico on May 13, with even protected waters hostingrough 4 to 5 foot waves, according to the Coast Guard. But three-plus weeks into the Deepwater Horizon explosion and ensuing spill from a BP exploratory well, measures to respond to the catastrophe continued ramping up.

Early last decade, the world’s tree coverage dropped by more than 3 percent. (p. 10)

One bird usually leads the flock, but sometimes another gets a turn at the helm.

Efforts to prevent global warming by fertilizing the oceans with iron could trigger harmful algal blooms.

A pinch of methylmercury is just ducky for mallard reproduction, according to a new federal study. The findings are counterintuitive, since methylmercury is ordinarily a potent neurotoxic pollutant.

A study of a rare Norwegian fossil narrows down when polar bears evolved and finds they are closely related to modern-day brown bears in Alaska. (p. 14)

Deep-sea currents can waft larvae hundreds of kilometers.

Oceanographers are finding more patches of floating polymers, some up to 20 meters deep. (p. 8)

PORTLAND — Sperm whales sometimes collaborate when they forage the depths, new tracking data suggest, with some individuals herding prey into dense schools while others lunge into the fray and feed. Scientists have long known that sperm whales, like many other toothed whales, form long-lasting social groups that typically consist of females and their young. While some researchers have suggested that the females in such groups collaboratively raise their young, the new data are the first to hint that the whales may engage in tag-team hunting. Bruce Mate, director of Oregon State University�...