An unusually high number of endangered Guadalupe fur seals have been found stranded on the shores of central California since the beginning of the year. Some of them were found dead, while others were alive but very weak, reported the Washington Post.

The National Oceanic and Atmospheric Administration declared an "unusual mortality event" for the seals Tuesday, saying the number of seals being stranded on California shores is eight times more than usual.

"Since January, approximately 80 fur seals came ashore along the central California coast," said NOAA in a press release. Usually, only 10 to 20 Guadalupe fur seal strandings occur each year.

Justin Viezbicke, NOAA fisheries stranding coordinator for the West Coast Region, said 42 of the 80 seals were found dead, while 38 were alive, but extremely weak. Scientists are attributing the fur seals' unusual mortality event to the abnormally warm waters of the eastern Pacific, which has driven the fish the seals feed on either farther north or father south.

"We think that warm water conditions have really changed the range of quite a few of the forage fish species that the fur seals would be going after," said Roby Garfield, director of the environmental research division at NOAA Southwest Fisheries Science Center, according to the Washington Post.

Tenya Norris of the Marine Mammal Center believes there may be more animals affected by the warm temperature.

"These stranded animals are just the tip of the iceberg in terms of animals affected by the unusually warm water temperatures we've been seeing off the coast," said Norris, according to Discovery News.

Guadalupe fur seals are listed under the Endangered Species Act. They are also protected under the Marine Mammal Protection Act. The fur seals, of which only an estimated 10,000 remain in existence, breed almost exclusively on Guadalupe Island.

NOAA's "unusual mortality event" declaration for the seals will allow more funds to be allocated for the study of the species.