See more of the story

Despite a decadeslong rescue effort, the tiny delta smelt appears closer than ever to vanishing from its only natural home, the Sacramento-San Joaquin Delta. "If current trends continue, and we don't get the numbers back up in the wild this year, we will be at a point where the only ones left will be in captivity," said Peter Moyle, an expert at the University of California, Davis.

New way to measure whales' stress

Whale researchers believe they've found a new way to measure whales' stress when they experience traumas such as entanglements in fishing gear, a technique that could help protect the creatures from extinction. The scientists, with the New England Aquarium in Boston, said the method involves measuring stress hormones by studying baleen, the bristly filter-feeding system in the mouths of the biggest whales. The baleen serves as a record that shows a spike in stress hormones, similar to the rings on a tree, lead author Rosalind Rolland said.

News services