The emaciated seven-month-old sea lion pup was cowering in the bushes along the coast north of San Francisco in a driving, cold rain when Sue Hawley gingerly approached.
Hawley put on gloves, grabbed a towel, tiptoed toward the brush, and reached in to pull out the scared animal. As she gripped firmly under its flippers, she could feel the bones of the trembling sea lion. She quickly set the pup in a crate for transport to the nearby rescue hospital, where she volunteers.
Once inside The Marine Mammal Center, Hawley gently placed the animal in a pen with other sea lions that were also recovering from the mass starvation that has been plaguing wildlife along the Pacific coast for the past four years. At only 22 pounds, it was barely more than birth weight. But dry, warm, and out of imminent danger, its eyes brightened.
“Her head was held high, and she just assimilated herself into the group,’’ Hawley recalled of the rescue last spring. “It was a beautiful scene, and it just touched me.” The pup is among thousands of starving marine mammals that volunteers, scientists, and veterinarians have encountered along the Pacific coast, especially in California, which is home to many marine mammal breeding grounds.
Partly driving the hunger is a dramatic decline in the numbers of sea lions’ main prey, sardines and anchovies, including around the Channel Islands, where many sea lions breed, according to fisheries scientists at the National Oceanic and Atmospheric Administration. That has forced the mammals, whose populations have been increasing in recent years, to prey instead on market squid and rockfish, which contain far less fat and fewer calories than do sardines and anchovies.
Scientists attribute the fish shortage to natural fluctuations in populations. Environmental factors, including El Nino and the still-present area of unusually warm sea surface temperature known as the blob, may continue to disrupt historical spawning times and locations of sardine and anchovy populations.
If the numbers of those prey species stay low, the sea lion population could fall drastically, says Shawn Johnson, the center’s director of veterinary science and head veterinarian, who adds that sea lion births are at half of historic rates and the pups are among the smallest seen in 40 years.
In normal times, mothers leave their pups at coastal breeding grounds and spend two to five days at sea feeding, followed by two days of nursing. But now, mothers are gone for up to 10 days at a time and return with only enough nourishment to nurse for a half-day or one day. This leaves the pups with barely enough strength to wean from their mothers and begin searching for their own food, which is why so many are washing ashore and ending up in facilities like The Marine Mammal Center.
And it’s not just sea lions: Hunger is also affecting other species, such as Northern and Guadalupe fur seals. In fact, The Marine Mammal Center has rescued a range of animals, including elephant seals that weigh more than 650 pounds.
Anchovies and sardines are among the prey species known as forage fish, on which marine mammals depend. These small fish are vital to ocean food webs, which is why some oversight bodies are moving to protect them. In federal waters off California, Oregon, and Washington, the Pacific Fishery Management Council has temporarily closed fishing for sardines until the population increases.
The council has imposed a cap on catch of anchovies, which are at low population levels, and also is looking anew at whether further action is needed to protect them and the role they play as prey in the ecosystem.
On a larger scale, the council has prohibited potential new commercial fishing efforts that target other forage fish species, such as lance and Pacific saury, until experts assess the potential impacts of such fishing on ocean life, including marine mammals, seabirds, salmon, and tuna.
Two months after Hawley brought the shivering pup to the center, workers returned the healthy sea lion to the water. But not every patient is so lucky; many are too sick to survive.
So far in 2016, the center has admitted more than 750 animals, some of which are still recovering. If they bounce back, they will be released with bright orange flipper tags or satellite trackers so that scientists can track and study them in hopes of better understanding how to protect them. The center’s rescue work and published studies are helping scientists link animal conditions to what’s happening in the oceans.
“The public adores these animals,” Johnson said. “And each of them has a greater story to tell. They’re sentinels of the sea and help us ring the alarm bell about the issues facing our oceans—trash, overfishing, ocean acidification.”
Hawley helps document those stories. She began volunteering in 2009, when she saw her first ocean animal rescue during an evening beach stroll with her husband, Rusty Rosenberg. Seven years later, their garage holds a rescue truck, crates, animal-handling gloves, and other gear. Between them, the retired restaurant owners volunteer about 900 hours a year.
To reach stranded animals, Hawley and Rosenberg often climb up and down cliffs, slip in mud, and endure soaking rain. To net an animal, one of them might distract the creature while the other sneaks up from behind. Next is the tricky step of hustling the animal into a crate, followed by the trek back to their truck, which sometimes involves walking hundreds of yards up hills or over rocks.
Once at the mammal center, Hawley helps feed and care for the animals. She rejoices with every life the center saves, but sometimes her efforts are in vain.
“You try real hard,” she said, her voice trailing off. “I know we’re saving lives. And we share with the world what we learn here. We have to start taking better care of the oceans, because if we don’t, things aren’t going to get better for the animals. We have a shared fate.”
Hawley’s determination to help outweighs her worries about the future. She relies on that confidence to steel herself for the next time the phone rings, sending her and her husband into the rescue truck and onward, to make a difference.