The number of dead harbor seals found washed up along the West Marin coast since early April has now risen to 35, the Park Service reported Wednesday.

The Marine Mammal Stranding Network has been surveying beaches and collecting information and tissue samples, with the samples being analyzed at UC Davis Veterinary School of Medicine.

"The likely cause of death," reported the Park Service, "is from a sudden virus since the general condition of the animals was determined, after evaluation, as good. There is no evidence of human intervention to date."

Most of the corpses found so far have been dead for several weeks, and most were north of Bolinas within the Point Reyes National Seashore, although five were found a week ago within Bolinas Lagoon.

The Marin Mammal Stranding Network, which is overseeing the investigation, is made up of several agencies and organizations, including the National Marine Fisheries Service, California Academy of Sciences, Museum of Vertebrate Zoology, Gulf of the Farallones National Marine Sanctuary, Marine Mammal Center, and the National Seashore.

Twenty percent of the state's harbor seals live in the National Seashore, and the Park Service this week asked the public to keep 100 yards away from harbor seals hauled out on land.

The Park Service also asked members of the public to call the Stranding Network at 750-7177, extension 2, if they find a sick or dead harbor seal.