With the lowest body weights ever documented, California sea lion pups are not only starving from lack of food, they’re infested with parasites and immune to antibiotics, said the director of the Pacific Marine Mammal Center.
The rehab center in Laguna Canyon is gearing up to care for sick sea lions and now northern fur seals, said Executive Director Keith Matassa. A record number of emaciated and dying sea lion and seal pups is expected along local shores this winter, scientists predicted last week.
The pups are starving due to warm-water El Nino ocean currents pushing the fish their lactating mothers eat into deeper, colder water. This causes the mothers to stay away longer, returning depleted with nothing left to nurse their young, said Sharon Melin, a National Oceanic and Atmospheric Administration wildlife biologist.
Last year, 3,500 sea lions and seals were rescued by various California marine rehab facilities. This year, the stranded pinnipeds are expected to hit 4,000. The survival rate is low, said Matassa. PMMC treated 135 sick pups last year and 50 percent died or were euthanized, he said.
“We’re not going to be able to save every sea lion out there,” said Matassa.
Late last December, the center went from 25 rescued pinnipeds to 100 in one week, he said. There are 29 rescued sea lions and four northern fur seals, rare in southern waters, already at the center this December. The animals are riddled with intestine-perforating parasites, known as thorny-head hookworms. “We’re seeing such a high level of parasites now, it’s not normal,” said Matassa.
With mothers away, the nursing pups wean early and stray from the rookery, looking for food. The fish they’re catching are adding insult to their untimely independence. “They’re eating trashy, small, shallow-water fish, fish that swim in tide pools like opaleye, which are a high-parasite fish,” he said.
Sardines, anchovies, market squid and rockfish, which predominantly comprise the adult pinnipeds’ diet, are cold-water and cleaner fish. Warm, shallow ocean water, he said, is dirtier and more conducive to bacteria growth.
When the infested sea lion dies, its body ends up on the ocean floor where bottom-feeders such as crabs and lobsters eat it, and the hookworm’s lifecycle continues, Matassa explained.
To treat the hookworm, rehab facilities are using anti-worming drugs, such as ones for human and canine tapeworms. Antibiotics for infections are proving ineffective.
Coming from the wild, the sea-faring animals are already immune to manmade antibiotics, he said. “They’ve never been given antibiotics and they’re already resistant,” he said, “so they’re picking them up in the water column somehow. All the antibiotics that humans take and excrete and the ones they flush down the toilet that they don’t take are ending up in the ocean.” Sea lions from the Atlantic on the East Coast, where Matassa worked prior to PMMC, were resistant to an even greater number of drugs, he said.
So many pups died in 2013 due to emaciation that NOAA declared the phenomenon an Unusual Mortality Event. Conditions have “not gotten much better over the past couple of years,” Melin said.
Melin surveyed three-month-old female sea lion and northern fur seal pups on San Miguel Island off of Santa Barbara for an annual assessment by the National Fisheries Service. Melin, NOAA climatologist Nate Mantua and stranding network coordinator Justin Viezbicke reported their findings last Thursday, Dec. 10.
At three months old, the average female sea lion is weighing in at only 26 pounds, 10 pounds underweight and the lowest recorded average since 1975, when NOAA first started assessing the pinnipeds’ health, Melin said.
Three-month-old female northern fur seal pups are in worse shape, weighing just one pound above birth weight, she said, at an average of 14.5 pounds. At their age, they would normally weigh 22 pounds, she said.
The food web, said Melin, “has been out of whack now for quite some time.” Global warming and ocean acidification due to carbon-dioxide emissions are other factors reducing fish populations, said climatologist Mantua. “We expect those influences to become bigger and bigger deals as we go,” he said.
A 100-mile wide band of warm water now extends from Alaska to Baja, Mantua said. That opens a corridor for subtropical species to swim up to higher latitudes and much closer to shore.
A semi-arid California climate may be evolving to subtropical, Mantua said. “If the average ocean temperature warms another two to three degrees Celsius as predicted by end of the century,” he said, “then we’ll become a more subtropical place really different from what we think of as the normal West Coast ocean.”
This is the fifth year out of the last seven that pups have been in poor condition, said Melin. The fact that northern pup seals are following suit signifies the domino effect of a distressed environment, she said.
Even so, the California sea lion population tops out at 300,000. “They’ve had a very good run,” she said, though she predicts a drastic decline to 100,000 due to low food availability.
How large a pinniped population a clean ocean can handle is unknown, said Melin, due to lack of data. “All these species were protected in 1972 under the Marine Mammal Protection Act,” she said. Populations were very depressed at that time.” Populations consistently grew each decade. “It can stand a bit of coming down,” Melin said.
“There’s so many stressors on the ocean right now,” Matassa said. “There’s the environment, there’s the animals and then there’s people and pollution from people. That’s a lot of stress for an ocean.
“If everybody took care of what they did with garbage, waste, how much water they use, how many resources they use, we could actually, possibly, reverse some of these things.”
Don’t Touch Stranded Sea Lions
People need to stay at least 500 feet away from a sick and stranded sea lion pup and never touch, coax or pour water on it, says Pacific Marine Mammal Center staff. Instead, call 949 494-3050, and save the number in your mobile phone.
“They are wild, they do bite,” said PMMC director Keith Matassa. And keep dogs away. The marine animals are out of the ocean because they are extremely stressed and not strong enough to swim. “Let them sit there in the sun a little while,” he said.
The public can also help by volunteering or contributing money to buy fish for food and other supplies. Pedialite, the basis of the center’s blended fish-food formula, is always welcome. PMMC’s website offers a wish list.
“I just bought 86,000 pounds of fish yesterday and that probably won’t even get us through the year,” said Matassa.
PMMC hired two animal care specialists, now four in total. “The animal care staff will double,” he said. “This all puts a big stress on funding.”
This year, a triage center has been set up in Huntington Beach to get the animals off the beaches as quickly as possible, test them and determine if they’re healthy enough for treatment at PMMC, Matassa said.
“People need to realize every animal on the beach does not need to be rescued,” he said. “Some of them will die before we get there, if they are that bad.”
Seven facilities that administer to live pinnipeds and just as many that deal with the dead ones exist along the California coast. “It’s very sad when one of the sea lions dies but they’ve left us a gift of their body,” Matassa said. “It’s so important to examine every animal that dies. We learn their life history, any diseases they’re carrying. That tells us what’s going on.”
Correction appended Jan. 20: The number of rescued sea lions was reported incorrectly due to misheard information. The center had rescued 575 as of Dec. 18, not 135.View Our User Comment Policy