The hatcheries of southeast Alaska spend months raising juvenile salmon until they're ready for life on their own in the wide-open ocean. The big day comes, the young fish are released, and they're ... immediately eaten by a hungry whale that's been waiting for this exact moment. A study published Tuesday in Royal Society Open Science found humpback whales have learned they can gorge on waves of salmon if they hang out around hatcheries during the times fish are released. The study started after a humpback whale was caught on video feeding near a hatchery in 2008. "This is a new source of prey, as far as we can tell," study author Ellen Chenoweth tells the New York Times.
New Scientist reports Alaskan hatcheries are acting like fast-food restaurants for the whales, who impressively navigate shallow water, the shore, docks, and holding pens to feed on the newly released salmon. So far the behavior doesn't seem to have spread to the humpback population at large but rather belongs to a handful of whales that have made it a key part of their annual feeding schedule. "In some cases, they return year after year," Chenoweth says. While humpback whales gobbling hatchery salmon isn't great for the economy of southeast Alaska, it could be a sign the whales—which once bordered on extinction—can innovate to survive climate change. "They will develop new tactics and do stuff you've never seen before," Chenoweth tells the Times. (Read more humpback whale stories.)