The massive die-offs that left Alaska beaches coated with tens of thousands of murre carcasses in 2015 and 2016 also took a big toll on the birds’ next generation when survivors failed to breed.

There was a near-total reproduction failure last year at all of the monitored breeding sites in the Gulf of Alaska and Bering Sea, federal biologists report.

At about 20 of the rocky outcroppings where common murres nest, lay eggs and hatch chicks, almost no fledglings were found, said Heather Renner, a wildlife biologist with the U.S. Fish and Wildlife Service.

Murres are black-and-white seabirds related to puffins and auks, are better at diving than flying, and look a bit like penguins. They are plentiful in Alaska’s waters, normally numbering about 2.8 million, according to the Fish and Wildlife Service.

“All of the colonies that I’m aware of in the Gulf of Alaska had complete failures…