ANCHORAGE, Alaska — The U.S. Fish and Wildlife Service says thousands of Pacific walruses have come to shore on the northwest coast of Alaska in their earliest appearance since sea ice has substantially receded.    

Agency spokeswoman Andrea Medeiros says several thousand walruses on Tuesday spotted on the barrier island near Point Lay.    

Point Lay is a village about 700 miles (1,126 kilometers) northwest of Anchorage.    

Sea ice allows immature walrus to rest as their mothers dive over the shallow continental shelf to eat clams and snails.    

However, when ice recedes beyond the shelf to water more than 10,000 feet (3,050 meters) deep, walruses are forced to beaches in Alaska and Russia, where they're vulnerable to stampedes.    

Federal biologists have documented herds as large as 40,000 animals in recent years.