Researchers at the Marine Mammal Center in Sausalito said the nonprofit has responded to 120 pups in the first five or six weeks of 2015. Last year the center didn't treat 100 pups until April.
"This is very alarming," said the center's spokeswoman Yvette Koth.
The birthing season started about seven months ago, and the pups are usually still nursing with their mothers on the Channel Islands until they're 11 months old, said the director of the center's veterinary science department Dr. Shawn Johnson.
The mothers may be abandoning their pups as they search for food, according to the researchers. The fish the seals eat may be feeding farther from the islands than in the past, causing mother seals may be going after the fish but not returning to their pups on the islands Koth said.
The other possibility is that the pups are suffering from an unidentified disease, Koth said.
Perhaps more alarming is that this is the third year the center has seen a larger than normal number pups needing help and the number seems to be growing each year, according to Johnson.
Last year 711 pups needed treatment. In 2013, 304 needed help.
The pups are turning up on beaches at about half the weight they should be. Johnson said the pups coming to the center are about 15 or 16 pounds when they should weigh 35 or 40 pounds or more.
Johnson called the pups "extremely emaciated and thin."
The Marine Mammal Center is the world's largest marine mammal hospital in the world. It serves 600 miles of the California coastline from Ft. Bragg in Mendocino County south to Santa Barbara.
Residents can help the center save the pups in two ways. Donations to the center will help it feed the pups, which are released into the wild once they are at a healthy weight. Reporting an emaciated pup to the center is the second way.
Researchers are asking that the public stay at least 50 feet away from any pups or sea lions when calling the rescue hotline at (415) 289-SEAL.
If residents can take a photo, the photo will help researchers know whether the pup needs help. Koth asked that residents also provide a good description of the location so rescuers can find the pup on the beach.