About 20,000 seals have died off the coast of Peru and Chile and thousands of elephant sea lions off the coast of Argentina.
About 300 seals have died off of Maine on the east coast and some in Puget Sound on the west coast.
Officials don’t know how to stop the rapid spread of the virus among the mammals.
In the case of poultry, the solution has been slaughtering infected flocks and imposing strict quarantines to prevent the disease from spreading to other flocks.
