When large numbers of marine mammals suddenly and unexpectedly begin stranding on beaches and dying, the incident is described as an unusual mortality event. While that term may be scientifically efficient and accurate, it does little to convey—at least in the recent case of starving California sea lions—the startling sight of limp forms dotting the coastline like lost, wet coats; the cacophony of dozens of corralled animals barking like hoarse dogs; and the smell of gallon after gallon of pureed herring and salmon oil flowing into desperately hungry mouths at rehabilitation centers.
And while such a declaration—made by the National Oceanic and Atmospheric Administration’s fisheries division—triggers access to better funding and research opportunities in the effort to find out exactly what’s weakening and killing animals, it’s really just the first step in a months- or even years-long endeavor. Sometimes the ultimate culprit is pinpointed as a biotoxin. Sometimes it’s an infection. Sometimes mass deaths come about as a direct result of human interaction.
In the current case, everyone already pretty much knows the problem: emaciation and dehydration.
A call to the Santa Barbara Marine Mammal Center in early April yielded this message: “All of the centers are having unusually large numbers of young California sea lions. They’re very small, skinny. They’re not getting enough to eat.
“These are not babies. They’re 9 months old. They’re already weaned by their mothers; their mothers are not coming back for them.
“We do try to pick up every one we possibly can, so please be patient. Right now all of the centers are working with overload capacities.”
But people aren’t sure why California sea lion pups born in the summer of 2012 aren’t getting the food they need. The animals have, on the whole, been weaned by now and should be capable of catching their own dinner.
“It’s not known with certainty why these sea lions are stranding so malnourished, but biologists’ studies from last spring suggested that this year’s supply of anchovies and sardines could be limited,” Jeff Boehm, executive director at the Marine Mammal Center, said on the organization’s website. “These two species of fish are an extremely important part of California sea lions’ diets, and females simply may not have been able to nurse their young sufficiently, resulting in abandonment, premature weaning, and subsequent strandings.”
So now, crossing that dangerous line from sleek to rib-revealingly skinny, young sea lions are listlessly washing up on beaches in the state’s five southernmost coastal counties. From San Diego to Santa Barbara, marine mammal rescuers have been operating in overdrive for much of the year, hauling weak pinnipeds to care centers, blending raw fish into smoothies that would make Dan Aykroyd proud, and tube feeding as many of the creatures as they can back to fighting weight.
Staffers and volunteers have begun transporting dozens of the animals north in an effort to spread the burden of their care among more busy hands. A starved young sea lion shrugging its way onto sands in the Los Angeles area may find itself loaded into a portable kennel and driven to Santa Barbara, then Morro Bay, then Monterey, then Sausalito. Handlers break the long journey into stages so as not to over-stress the creatures already weak from hunger.
“We took in 30 California sea lions from various rescue centers in Southern California,” Jim Oswald, public relations manager for the Marine Mammal Center, said by phone from the group’s Sausalito headquarters. “We also took in from those facilities about five elephant seals, one harbor seal, and two northern fur seals, all so we could free up space for those facilities.”
He explained that fur seals need more space for rehabilitation, as do elephant seals. Moving one elephant seal, for instance, makes room for two or three sea lions.
As of this report, workers in Sausalito were considering sending some animals north to Crescent City, almost at the Oregon border, where a Marine Mammal Center facility still had some room to spare.
Facts and figures
There have been 57 formally recognized unusual mortality events in the United States since 1991, when the marine mammal program that officially identifies such occurrences began. The 2013 declaration marks the 17th such event recognized on the West Coast, and the sixth for California sea lions.
Out of all the states, California has seen the most such events. And while bottlenose dolphins top the list of animals stranding and dying, California sea lions come in second. They’ve previously fallen prey to leptospirosis, a bacterial disease; to unfavorable conditions caused by El Niño; and to domoic acid toxicity, which originates in algae and works its way up the food chain, accumulating in larger animals, which ultimately suffer brain damage.
The National Oceanic and Atmospheric Administration reported an estimated 296,750 California sea lions off the coast today, with an annual population increase of 5.4 percent. From the early ’80s to 2003, that growth number was actually 6.5 percent, but, as the administration’s Office of Protected Resources noted in a published list of sea lion facts, “the growth rate has decreased since the 1990s as the population approaches the carrying capacity of its environment. The stock is within its ‘optimum sustainable population’ limits.” That means, per the eye-glazing terms of 1972’s Marine Mammal Protection Act, that the animals have reached the “maximum productivity of the population or the species, keeping in mind the carrying capacity of the habitat and the health of the ecosystem of which they form a constituent element.”
Translation: They’re not endangered. They’re not even threatened. California sea lions are doing well on the whole.
Some people, in fact, think the animals may be doing a little too well. Another die-off a few years back prompted experts to speculate on the reason behind missing food supplies and fishermen to theorize that overpopulation could be the culprit.
Keep in mind that animals currently being rescued represent a single, youthful demographic. Bony adults aren’t washing up on shore. Neither are sickly newborns.
We’ve seen this before
“In 2009, there was a huge influx of sea lions pups, just like this,” said Oswald at the Marine Mammal Center’s Sausalito headquarters.
He explained that the center is in many ways considered to be the world’s largest rescue and rehab center that’s not a zoo or aquarium.
“We took in 1,700 marine mammals. We normally take in between 500 and 800 each year,” he said, noting that a little more than 1,300 of those mammals were California sea lions—and that about half that number was made up of pups.
“Many were so emaciated that no amount of food or medication could save them,” he said.
He explained that studies revealed the food stock had shifted farther offshore than usual. Scientists working at the time knew the sardines and anchovies had moved—as opposed to totally disappearing—because the adults were healthy, Oswald said. As larger, more capable animals, the grown sea lions wouldn’t have much trouble hunting in deeper waters farther from land.
Young sea lions, however, are wired to transition from their mothers’ milk to foraging for fish where they were born. Unfortunately for them, the fish just weren’t there that year.
Oswald said that this year’s situation looks similar to 2009’s. He explained that biologists studying the problem seem to be pointing toward a disappearance or lack of the particular types of food young sea lions eat, such as anchovies or sardines. More than 1,000 juvenile sea lions have been found ashore so far this year, and the ones that are on the road to recovery are making up for lost meals. They’re fed four times a day.
“We expect, by the end of this month, to go through as much as 60,000 pounds of herring to feed the patients. … It’s an incredible amount [and] that’s just for the spring season,” Oswald said. “Given the way that things are going, we’re probably going to utilize somewhere between 90,000 and 100,000 pounds for the year.”
And still, not every sea lion survives. But Oswald noted that these die-offs aren’t wiping out the populations.
“What is disturbing,” he said, “is starting to understand what’s happening to the food sources.”
So what is going on? Is it warming oceans? Overfishing? Pollutants? A combination of all of the above? The specifics are to be determined by the experts, Oswald said—and we should pay close attention to what they find.
“Here, we refer to sea lions in particular as kind of like the canaries in the coal mine,” he said. “They literally are. They’re literally the top of the food chain. What they eat, the environment they’re in, it really is similar to what humans desire: to work, live, and play in coastal areas. [We] eat much of the same fish sea lions eat: herring and squid—calamari, you know—anchovies on our pizza. When these guys get ill, that’s an indication of what’s going on out there.
“What harms them could very well be harming us,” he added. “Of course, I don’t mean to sound alarmist.”
Hungry people
Diane Pleschner-Steele, executive director of the California Wetfish Producers Association, spoke to the Sun by phone while she was heading back to her Buellton office from a Pacific Fishery Management Council meeting in Oregon, where the body adopted a long-in-the-works Fishery Ecosystem Plan. She was traveling by train as part of an effort to reduce her carbon footprint.
She keeps one eye on the industry and one eye on the environment, both filtered through a lens of science. She’s got a hand in writing and workshops exploring the impacts of ocean acidification. Her group represents fleets in San Pedro, the Pt. Hueneme/Ventura area, and Monterey.
A “wetfish,” by the way, is a fish that was historically canned fresh from the sea. Now, they’re known as coastal pelagic species—pelagic referring to open ocean dwellers: mostly sardines, anchovy, mackerel, and market squid.
The group’s website reports: “In 2010 (the latest [California] totals available from Department of Fish and Game), wetfish still represented the lion’s share of the commercial fishery harvest: 84 percent of total commercial seafood landings, and 44 percent of ex-vessel value.”
As of right now, however, observers might not get that sense.
“We haven’t had a fish landed in 2013,” Pleschner-Steele said.
Her group takes $3 per ton of wetfish that comes across the dock. The money funds the association, which also does a lot of research and works with the Department of Fish and Game and the Southwest Fisheries Science Center. But no fish coming in means no funds coming in, either.
“We haven’t had any revenue since the end of December,” she emphasized, “which is … very unusual, but ocean conditions are, I think, 100 percent of the explanation for it. It’s certainly not overfishing.”
Steve Scheiblauer, harbormaster for the Monterey Harbor District and a contact person for the California Fisheries Coalition, echoed that belief.
“The number of malnourished young sea lions is certainly heartbreaking,” he wrote in an e-mail to the Sun. “Right now, ocean conditions are such that ecosystem dynamics are managing many species. … Here in Monterey, anchovies, squid, sardines, mackerels, salmon—are all not present. This is somewhat similar to last year, where squid and sardines didn’t show up until later in the year, and then they did in great abundance, [especially] squid (a favorite food of sea lions). This is particularly hard on young sea lions, who can’t swim as far to find food. I’ve seen this cycle many times in my 38 years working at Monterey and Santa Cruz harbors. It is not related to fishing effort at all, in my observation.”
Environmentalists may find an easy demonization target in fishing organizations, but Pleschner-Steele said her group has been getting noticed for its precautionary management of pelagic species and is weighing in on developing ecosystem plans. While overfishing may be a global issue, she’s part of a group working to make sure at least the United States isn’t depleting the sea.
“We’re gaining recognition, finally, that our precautionary management is the best in the world, really,” she said.
There’s even evidence of their management having not just minimal, but positive impacts on the ocean, she added.
Still, the ocean is a big system, and we humans still don’t fully understand it. Pleschner-Steele likened it to a waterbed: When you push down on one end, the other end bulges up. Plus, there are large-scale weather patterns and long-term cyclical changes. Think El Niño and the associated La Niña. There’s cold water and warmer water shifting around in a constant swirling give and take out there, and if conditions aren’t right for a particular species, there’s not much anybody can do about it. This all contributes to what’s known as cycles of abundance.
“The ocean naturally has these cycles of abundance, and we’re not entirely sure what triggers the longer-term cycles,” she said.
And like a sort of reverse Goldilocks, sea lions’ favorite fish to forage don’t like it just right.
“The sardines tend to favor the warmer water, and anchovies tend to favor the colder water, and where we are now in the long cycle is heading from the warm phase of the [Pacific Decadal Oscillation] that started in the middle of the 1970s and ended probably in the middle of the 2000s,” Pleschner-Steele explained.
The balance is always dynamic, she said, noting, “You can’t have it all. There’s going to be this, or there’s going to be that, but there’s not going to be this and that at the same time. We can’t have sardines and anchovies at the same time at peak abundance.”
Couple less-than-ideal conditions for certain fish at this time of year with the California sea lions’ current success as a species, and you’ve got a theory for the starvation and strandings. Pleschner-Steele called it “Mother Nature’s Way of leveling the playing field.”
“Mother Nature, that’s her way of taking care of business,” she said. “There’s not enough, it’s the survival of the fittest, and pups are the less fit, less able to travel, less able to forage, and that kind of levels the population so that there’s enough food to feed what’s left.”
Still, as noted above, that’s a theory.
“Mother Nature knows. We can only guess,” Pleschner-Steele admitted. “We’re getting better at guessing, but we don’t know as much as she does. That’s both the wonder and the frustration for those of us who try to operate on a science level.”
Contact Executive Editor Ryan Miller at rmiller@newtimesslo.com.
This article appears in Apr 25 – May 2, 2013.