Ocean waters off the West Coast of the U.S. are hitting record temperatures—two to six degrees Fahrenheit above normal. “It’s as warm as we have ever seen it,” says NOAA climatologist Nate Mantua. “And there’s no historical precedent for it getting any warmer than that, so it’s kind of hitting its peak.” The warming pattern appears to be caused in part by a slowdown of coastal winds that bring cool, deep ocean water to the surface, delivering nutrients and cooler temperatures.

Mantua says it’s unclear whether human-caused global warming plays a role in the weird wind pattern. But regardless of the cause, warmer waters are changing the distribution of food in the Pacific, stranding hundreds of starving sea lion pups on shore, and causing the death of hundreds of thousands of birds.