Young seals, sea lions starving in record numbers Emaciated young animals stranded along coastline

A sea lion too young to eat fish is fed nutrients at Sausalito's Marine Mammal Center. A sea lion too young to eat fish is fed nutrients at Sausalito's Marine Mammal Center. Photo: Paul Chinn, The Chronicle Buy photo Photo: Paul Chinn, The Chronicle Image 1 of / 15 Caption Close Young seals, sea lions starving in record numbers 1 / 15 Back to Gallery

Rescuers are scrambling to save a record number of young sea lions and seals along California's northern and central coast while scientists work to understand why the animals are beaching themselves - and in one case swimming and waddling all the way to an almond orchard near Modesto.

The emaciated and dehydrated pups are turning up along the 600 miles of coastline from Mendocino to San Luis Obispo monitored by the Marine Mammal Center. Many are too weak to move after washing ashore during their almost yearlong weaning.

The group has more than 1,000 volunteers who respond to reports of strandings by alarmed beachgoers and others. They clean, feed and medicate the hundreds of animals filling a rescue center in the Marin Headlands. Lately, they've been busy - and burning through 1,000 pounds of herring a day.

"The ones we are seeing are basically starving to death," said Dr. Shawn Johnson, director of veterinary sciences at the center, which has field offices in Mendocino, Monterey and San Luis Obispo counties. "It's definitely a mystery. We're hoping it's not the new norm."

As of Wednesday, the center had brought in 429 California sea lions, elephant seals, harbor seals and fur seals this year. That's well above the 291 animals admitted by the same date last year and surpasses the record of 388 animals for the time period, set in 1998.

Changing fish stocks

Johnson said many of the animals may be struggling to find enough food because of changing fish stocks. Another suspected culprit is a huge recent bloom of toxic algae in Monterey Bay, which has killed sea birds and prompted public health officials to warn consumers not to eat certain types of fish and shellfish.

Algae blooms, also known as red tides, have proliferated in recent years and produce a neurotoxin that accumulates in shellfish, mussels, anchovies, sardines and herring, a primary food source for California's 300,000 sea lions. The neurotoxin, domoic acid, can cause memory loss, tremors, convulsions and death.

"It was first diagnosed in the Marine Mammal Center in 1998," Johnson said. "There was a huge outbreak of sea lions having seizures. Now that we recognize it, the Public Health Department is looking for it because it affects humans, too."

The record number of rescues comes a year after Southern California witnessed an almost 70 percent die-off of young sea lions - those born in summer 2012 - near the Channel Islands, where most American sea lions breed.

Government scientists perplexed by the hundreds of starving pups washing up in San Diego, Orange, Los Angeles, Ventura and Santa Barbara counties declared an "unusual mortality event" and began an investigation. Previous die-offs were blamed on domoic acid, El Niño conditions and leptospirosis, a bacterial infection.

Officials have not directly linked this year's strandings to the die-off. Sharon Melin, a wildlife biologist with the National Oceanic and Atmospheric Association, said last year's stranded pups were around 6 to 8 months old - a few months shy of the 11-month point, when they typically venture out on their own.

The seals and sea lions beaching themselves in recent months are around the age when they finish weaning after being born last summer. Rescuers say they usually see more stranded pups this time of year - just not in such vast numbers.

"We probably won't have a whole understanding for a few years. In 2013, it was only the young animals that tried to do it on their own," Melin said. "Now this year there's lots of stranding going on, but those are a different age-class of pups."

Confused pup near Modesto

In early April, workers at a ranch near Modesto were dumbfounded when they came across a confused sea lion pup in the middle of an almond orchard. The pup, later named Hoppie, reportedly swam up the San Joaquin River before waddling almost a mile into the orchard about 100 miles from the ocean.

Hoppie was rescued by the Marine Mammal Center, where he was nourished and treated for sores. The unlikely journey made headlines around the country, but experts stressed that it might have underscored a more serious problem for sea lions.

With beach weather beginning to arrive in Northern and Central California, experts are urging people who come across a seal or sea lion pup that appears healthy to leave it alone. Often, a mother will spend her days seeking food, leaving the pup behind.

Animals that appear to be ill, though, can be reported to the Marine Mammal Center's hotline, allowing trained volunteers to respond. If they determine the animal needs help, they will bring it to the rescue center, where crews of 30 people begin an aggressive rehabilitation regiment.

"We rescue, rehabilitate and release them as quickly as we can," Johnson said.

Rescue efforts 429 Sea lions and seals treated at Marine Mammal Center in 2014. 291 Marine mammals treated during same span last year. 388 Record number of animals treated during span, in 1998.