"It would be so much easier if the whales had faced just one problem.
In the decade since Puget Sound’s southern-resident killer whales were protected under the Endangered Species Act (ESA), scientists have figured out where orcas go in winter. They’ve learned these whales can tell a chinook from a sockeye by using sonar to detect small differences in each fish’s swim bladder. And researchers have documented the many ways these majestic mammals shift behavior in response to propeller and engine noise from boats.
Yet despite the vast rise in knowledge since killer whales were listed as endangered in 2005, the region’s orca population — already a fraction of what it was in the 1960s — still is not growing, according to a new synopsis of research on the cetaceans by the National Oceanic and Atmospheric Administration (NOAA)."