11/10/18 11/10/18

Major Disease Outbreak Strikes California Sea Lions

preamble —

This article stated: The National Oceanic and Atmospheric Administration announced in January that California sea lions had reached carrying capacity—the number of individuals their environment can sustainably support—in 2008.

The expected symptoms of a population of mammals at carrying capacity include reduced reproductive output, decreased growth and survival of young animals, delayed sexual maturity, increases in disease or parasites and decreased size and survival of adults. There have beenrecent increases in California sea lion pup mortality and reduced pup growth rates, as well as increased incidence of leptospirosis observed in central California and Oregon, leading to the suggestion that the population is approaching carrying capacity (McClatchieet al. 2016).

Leptospirosis afflicts sea lions on a semi-regular cycle, but warming waters and migrating fish could make the marine mammals more susceptible

Princepajaro, a male California sea lion, swims in a pool during treatment for leptospirosis at The Marine Mammal Center in Sausalito, CA. When a leptospirosis outbreak occurs, the Center’s scientists study the disease to learn more about what causes an outbreak and how we can improve treatment for infected animals. (Bill Hunnewell / The Marine Mammal Center)

Shawn Johnson knew it was coming.“Last fall, we saw a few cases,” he said. “And that was a warning signal, so we were prepared—well, we weren’t prepared for this level of an outbreak.”Over the past month, Johnson, director of veterinary science at the Marine Mammal Center, just north of San Francisco, and his team have been getting an average of five sick California sea lions a day. The animals have leptospirosis, a bacterial infection that affects their kidneys, causing fatigue, abdominal pain and, more often than not, death.As of October 16, Johnson’s team had seen 220 sea lions with the disease, which made it the center’s second largest outbreak. Since then, the center reported 29 more sea lions have been rescued and 10 of those died due to leptospirosis. More than a dozen animals are still awaiting diagnosis. The number of cases has started to slow, but if historical trends hold up, Johnson expects this outbreak to eventually surpass 2004’s record of 304 cases of sea lion leptospirosis.

The Marine Mammal Center in Sausalito, CA, is responding to an outbreak of a potentially fatal bacterial infection called leptospirosis in California sea lions. The pictured sea lion, Glazer, is seen curled up with his flippers folded tightly over his abdomen prior to his rescue by trained Center responders in Monterey. The posture exhibited is known as “lepto pose,” and is often an indication the sea lion is suffering the effects of the disease. (The Marine Mammal Center)

All told, about 70 percent of the sea lions the team tried to save have died.Leptospirosis outbreaks among sea lions occur at fairly regular intervals, but changing ocean conditions—warmer waters and relocating fish—are affecting how the disease strikes populations along the Pacific Coast. The threats aren’t new, but they’re threatening in slightly new ways. Changes in marine conditions appear to be affecting the population’s resiliency to this disease and others. While researchers scramble to save sick sea lions today, they are also studying what this year’s outbreak can tell us about how sea lions will fare down the line.The good news is that sea lions are fairly mobile and resilient animals. And until recently, their populations were booming. The National Oceanic and Atmospheric Administration announced in January that California sea lions had reached carrying capacity—the number of individuals their environment can sustainably support—in 2008.Since then, though, their numbers have fluctuated. A “blob” of unusually warm and long-lasting water moved in along the West Coast from 2013 to 2015, causing widespread algal blooms that spread a neurotoxin called domoic acid throughout the marine food chain. Sea lions with elevated levels of the toxin suffered brain damage, resulting in strokes and an impaired ability to navigate, ultimately killing most of the afflicted individuals.The warm water also sent fish and smaller marine life out to search for cooler environments, meaning the sea lions had to travel farther to find food. The combination of more distant hunting and impaired navigation led to record numbers of stranded pups—many taken in by the Marine Mammal Center—as well as a dip in the sea lion population during those years.

California sea lion Yakshack is one of 220 patients at The Marine Mammal Center in Sausalito, CA, that has been rescued so far this year impacted by a bacterial disease known as leptospirosis. The Center has been at the forefront of research on leptospirosis in marine mammals and has published a number of scientific papers on the disease dating back to 1985. (Bill Hunnewell / The Marine Mammal Center)

But the warm water conditions also led, ironically, to a decline in cases of leptospirosis during that time. Over the past decade, scientists have determined that the disease, which spreads via a parasite, is endemic to the population. Some animals carry the disease and don’t get sick, but they do excrete the parasites in their urine, which is how it spreads to other individuals. When sea lions haul out on a pier or beach, they freely roll around in each other’s pee.When the blob of warm water appeared, sea lions had to swim farther to find food and had less time to haul out and be social, Johnson says, meaning less time sitting around in each other’s pee and parasites—and fewer cases of leptospirosis. But the lack of the disease a few years ago led to consequences today. Sea lions that get leptospirosis and survive develop antibodies that fend off the parasite in the future, says Katie Prager, a veterinarian researcher at UCLA’s Lloyd-Smith Laboratory who collaborates with the Marine Mammal Center. These antibodies, however, cannot be inherited by offspring.“It’s not something that can be passed on,” Prager says. “Antibodies are something that the pup has to develop on its own.”The warm waters meant fewer sick sea lions, but it left the population very vulnerable. Now the disease is back with a vengeance.“A lot of the animals are now naive to that bacteria and their immune systems haven’t been exposed to that,” says Alissa Deming, a veterinarian researcher at Dauphin Island Sea Lab in Alabama who previously studied sea lion diseases at the Marine Mammal Research Center. “There is a group of animals that haven’t seen this before.”The risk, according to the researchers, is that continued domoic acid outbreaks could result in a vicious cycle—fewer cases of leptospirosis produce unexposed populations, and then major outbreaks flare up like we are seeing this year.“This is a great example of how environmental change has so much impact on a wild species—all the way from where they eat, where they migrate and how their diseases change over time, just based on a few degrees’ increase,” Johnson says.

California sea lion Herbie lays on his pen floor during treatment for leptospirosis at The Marine Mammal Center in Sausalito, CA. Veterinarians can usually identify leptospirosis in a patient even before laboratory tests confirm a diagnosis because of the infection's distinctive symptoms in California sea lions, which include drinking water and folding the flippers over the abdomen. (Bill Hunnewell / The Marine Mammal Center)

The first documented case of a marine mammal suffering from the domoic acid toxin was in 1998, and the events are now increasing in frequency—so much so that the spread of domoic acid has become a yearly sign of the changing seasons around San Francisco Bay. “The days are getting shorter, pumpkin spice lattes are here and once again, it’s time for that other Bay Area rite of fall: worrying about the levels of toxins in local Dungeness crabs,” begins a recent San Francisco Chronicle article on the influence of the toxin on the start of crabbing season.Sea lions don’t wait for permission from the Department of Public Health before they start eating crabs, though.To exacerbate the issue even more, an El Nino event is predicted over the coming months, meaning warmer ocean waters off the West Coast and possibly more algal blooms and toxins. Already, Southern California waters—where researchers have found some of the highest concentrations of diatoms that produce domoic acid—have had record high temperatures this year.NOAA has even deemed the recent warm-water years a “climate change stress test” for West Coast oceans. The agency said the conditions “may offer previews of anthropogenic climate change impacts projected for the latter part of the 21st century.”If this has been a test, sea lions might not have passed, says Robert DeLong, a scientist with NOAA’s Alaska Fisheries Science Center. DeLong has been studying California sea lions for decades at their breeding grounds, Channel Islands off Santa Barbara. He says the species should be pretty resilient in the face of climate change, but the rate of warming waters is proving a major challenge.

Volunteers from The Marine Mammal Center in Sausalito, CA, release California sea lions Bogo (left), Brielle (center), and Biggie (right) back to the wild near Bodega Bay. All three sea lions were treated for leptospirosis at the Center’s Sausalito hospital. Many different animal species, including humans and dogs, can become infected with Leptospira through contact with contaminated urine, water or soil. The Center has a number of safety protocols in place to prevent transmission to veterinarians and volunteers working with sea lion patients. (Bill Hunnewell / The Marine Mammal Center)

The center of the West Coast sea lion population is around Baja California, so the species has adapted to warmer water than is currently being seen farther north up the coast. “They have that capability to live in warmer water,” DeLong says. And unlike, say, coral reefs, sea lions are very mobile, able to swim long distances to find suitable habitats.But while males can chase food far up north, during the breeding season females are tied to a small radius around the rookery. If there is less food available there because fish have moved to cooler waters, it could present a major problem for sea lion mothers and their pups.“So if this is what climate change looks like, and this period is an adequate proxy, if that’s really the case, then sea lions may not do as well as we would think,” DeLong says.There are still signs of hope. Sea lions are increasingly moving north to new breeding grounds off the San Francisco Bay, for instance. The limiting factor is time.“If the environmental changes are slow enough to adapt, they’ll be able to move and will probably move farther up the coast,” Johnson said. “If changes are slow enough, I could see them being able to adapt.”

Original post: https://www.smithsonianmag.com/

11/25/17 11/25/17

Biggest Chinook Salmon Haul Going to Sea Lions, Seals & Killer Whales

A young resident killer whale chases a chinook salmon in the Salish Sea near San Juan Island, Washington, in September 2017. Oregon State University, Flickr Creative Commons

It’s been a long haul, but West Coast seal and sea lion populations have recovered over the past 40 years. All those extra predators may be eating more chinook salmon than people are catching, according to a new study.Increasing numbers of marine predators could be bad news for chinook salmon — and for critically endangered Southern Resident killer whales.In a new study published in the journal Scientific Reports, researchers used models to estimate how many salmon marine mammals are eating.“The reality is, if (marine mammal) population numbers are increasing, undoubtedly their consumption and predation is also increasing,” said Brandon Chasco, the study’s lead author and a Ph.D. candidate at Oregon State University.Turns out, sea lions, harbor seals, and growing populations of killer whales in Alaska and Canada are consuming almost 150 percent more chinook salmon than they did 40 years ago. That’s compared to a 41 percent decrease in the amount of chinook salmon fisheries are harvesting.“This sort of thing has been documented around the world — recovery of seals and sea lion predation on fish that lots of people care about and harvest,” said Isaac Kaplan, with NOAA Fisheries Northwest Fisheries Science Center and study co-author. “But really putting the diet information together and doing the sort of careful accounting … it really emphasizes the strength of that impact on the chinook salmon population.”As the juvenile salmon swim out to sea, they get eaten by seals and sea lions. Then some salmon swim clear up the coast to Alaska, where booming populations of killer whales take a bite out of the chinook numbers.As the salmon then migrate back to spawn in Northwest streams, there are fewer fish for the southern resident killer whales in Washington’s marine waters.The researchers said all that means chinook salmon could be doing better than previously thought — they’re just getting gobbled up before returning home and getting counted.“There is a conflict. There is a trade-off here,” Kaplan said. “To some extent, it means that recovery of chinook salmon populations has been more successful than we realized — it’s just that some of that success is going towards feeding marine mammals.”The sea lions and seals are protected by the U.S. Marine Mammals Protection Act of 1972. At the same time, the Endangered Species Act protects chinook salmon.Columbia River tribes of Native Americans have recently fought to protect salmon runs from the pinnipeds, asking for authorization to kill more of the sea lions that feast on the fish.The study, funded by the Pacific Salmon Commission, found that sea lions and seals are eating more individual fish, while killer whales are eating more biomass, or weight, of fish. It’s unclear, right now, which number has a bigger impact on salmon numbers, Chasco said.The researchers said salmon recovery efforts must take into account all the different challenges salmon face, including these increasing marine mammal predators studied.Right now many salmon survival models focus more on ocean conditions and commercial and recreational fisheries. Taking more of an ecosystem approach to managing salmon might be a better way to go, the researchers said.“There’s more than just fishing to the story (of salmon recovery). There’s also predation,” Kaplan said. “This study helps us understand that there are multiple pressures acting on salmon.”But there’s still much more to study, Chasco said.For example, he said, “Is this an additive effect, or is it these predators simply taking fish out of the mouths of other predators?”

Originally published: http://www.opb.org/news/article/salmon-haul-seals-sea-lions-killer-whales/

7/14/16 7/14/16

Stinky Sea Lions Inspire Wacky Deterrents—Like Fake Orcas

Sea lions have angered human neighbors in La Jolla, California, with their smells and sounds, kicking off a public battle.

Along North America's West Coast, human beings are wrestling with the triumphant return of the slippery California sea lion.

The thick-bodied creatures in La Jolla, California, muscle their way into lifeguard chairs, block access to public steps, and laze about on dry rocks, where the sun bakes their feces into a stench that clears out nearby restaurants.

Up north in Oregon, these sleek swimmers so completely take over docks and marinas that port officials repel them with paint guns, electric mats, and the same Gumby-like wiggling inflatable air dancers that usually advertise clearance sales at car lots. Still, the animals keep coming.

And 145 miles (235 kilometers) up the mighty Columbia River, sea lions now feast on so many endangered fish that the federal government last week renewed authority for states to remove or euthanize the most gluttonous of the predators.

Forty-four years after passage of the Marine Mammal Protection Act (MMPA), the population of smart, muscle-bound sea lions has climbed to almost 300,000. That’s a far cry from the 1930s and 1940s, when these animals dipped to less than 20,000 and may have numbered as few as 10,000. For a fish-eating critter once slaughtered for dog food, its blubber sold for oil and its whiskers used as tobacco pipe cleaners, that is a stunning comeback.

"It's one of the greatest success stories we can talk about in terms of marine mammals," says Garth Griffin, with the National Oceanic and Atmospheric Administration in Oregon. "The MMPA flat out did its job."

But how well are we learning to live with that success?

During the last few years, thousands of baby sea lions were stranded in southern California as ocean changes redistributed their mothers’ prey. The images of these starving young mammals may have overshadowed another phenomenon: Even as juveniles were dying, adult males were congregating in record numbers in a few unfortunate places, destroying docks, sinking boats, and munching scarce stocks of salmon.

One Oregon port last year even deployed a boat painted like a sea lion-eating orca. It was supposed to emit whale noises in an attempt to scare the whiskered critters off. It capsized.

These beautiful barking animals keep finding new ways to bamboozle us.

"Overall, California sea lions are doing quite well, and that's a good thing," says Chris Yates, assistant regional administrator for NOAA Fisheries. "However, it hasn't come without consequences. Once these animals settle in a place, they can be very hard to deter." (See how sea lions and other animals may hold cures for cancer.)

*Sea Lions of San Fran Locals and tourists gather to see Pier 39’s rowdy sea lions in the heart of San Francisco.*

A Marine Mammal Fracas

Few people are coming to understand that better than Steve Haskins. While serving as president of the La Jolla Town Council, a community within the city of San Diego, the local real estate attorney landed in the middle of a small marine mammal fracas.

For more than a decade, some in his community had been embroiled in a surprisingly bitter spat over a group of harbor seals that commandeered a tranquil beach where residents taught their kids to swim. Those seeking protection for this fresh habitat and those itching for continued beach access faced off in lawsuits and public screaming matches. There were death threats, arrests, even a fist fight with a stun gun.

In the midst of this melee, a handful of sea lions arrived and began hauling out on rocky bluffs above popular La Jolla Cove, less than a quarter mile from outdoor restaurants and fancy hotels. The fetid mess left behind, along with the waste from cormorants and other seabirds, sometimes proved overwhelming in a community where tourists pay to eat outside.

The city sprayed a special microbial foam to counteract the stink. That eliminated the wafting odor of bird poop, but did little to knock down the sea lion's musky funk.

"We're pretty temperate, so the sea lion droppings would stay there and the sun would hit and it would get very, very smelly," Haskins says. "It would go up into the restaurant district and drive people crazy."

The same attorneys who sued to protect the seals went to court to try and force the city of San Diego to clean the waste. They argued the smell of sea lion-digested anchovies was costing businesses too much money.

"The professional boxer Floyd Mayweather, for example, recently booked two villas and six rooms for his entourage at the historic waterfront hotel La Valencia, but checked out 15 minutes after arriving because of the noxious odors emanating from La Jolla Cove," the suit claimed.

A judge dismissed the case. A rise in bacteria in the water this year even spiked a popular open-ocean swimming race.

So Haskins and others kicked around solutions, ranging from spraying animals with hoses to mounting a set of rollers on the rocks that would make it hard for sea lions to haul out in the first place. But then this year, the animals shifted gears; they began congregating on a popular protected beach.

"The only way in or out is to swim, or there are two sets of stairs going down to the beach," Haskins says. "What the sea lions would do is get on the stairway and sit there. They'd block it. People on the beach couldn't get out. Then they'd climb into the lifeguard stations. Lifeguards were dealing with sea lions and not watching for people drowning."

Haskins isn't sure what comes next.

"No one wants to do anything that might harm marine life," he says. "It may be one of those things for which there is no good answer."

Read the original post: http://news.nationalgeographic.com/

7/7/16 7/7/16

NOAA authorizes Oregon to continue killing sea lions to save endangered fish

The National Oceanic and Atmospheric Administration has authorized three northwestern states to continue killing sea lions that prey on endangered fish species as they try to climb the fish ladder at the Bonneville Dam, officials said Wednesday.California sea lions often congregate at the mouth of the the Columbia River and in the waters just below the dam, the Oregon Department of Fish and Wildlife said in a statement, and the hungry marine mammals have put a big dent in the numbers of salmon and steelhead looking to make their yearly migration upstream."Last year sea lions were estimated to have consumed nearly 10,000 adult spring Chinook salmon, amounting to more than 3 percent of returning adult fish," the administration said in a statement. "The impact on individual populations within the run may be much higher. An estimated 25 to 35 percent of the fish consumed are listed under the Endangered Species Act." The authorization for Oregon, Washington and Idaho to trap and euthanize the sea lions will run for five years, the administration said in a press release, and is just one tactic the government is trying to help bolster the numbers of flagging fish species.Oregon officials have tried exclusion gates, pyrotechnics and shooting the animals with rubber buckshot to dissuade the animals from congregating to feed at the dam, but all of those efforts only work temporarily, Oregon officials said.Problematic sea lions that have been observed feeding near the dam's fish ladders are individually identified and trapped. Though officials would prefer to relocate the animals to zoos or aquariums, that isn't always possible and the animals sometimes have to be killed as a last resort.Since the effort began in 2008, some 166 animals have been removed, 59 of them this year alone. Of 166 sea lions removed, 15 went into captivity, seven died of accidental deaths and 144 were euthanized, a spokesman for NOAA said.Since the states began the program in 2008, officials estimate 15,000 to 20,000 salmon and steelhead have been saved from predation.There are about 300,000 California sea lions off the west coast and the authorization only allows for 92 animals to be removed per year. The authorization also precludes removing any Steller sea lions, which are protected by the Marine Mammal Protection Act.— Kale Williams kwilliams@oregonian.com

Read the original post: http://www.oregonlive.com/

6/17/16 6/17/16

La Jolla Sea Lion Situation Now A ‘Crisis’

Photo by Katie Schoolov - Visitors in La Jolla Cove stand on the bluffs along the ocean, Nov. 19, 2015.

The ongoing poop problem in La Jolla appears to be getting worse.How much worse?Residents are now calling it a crisis."It’s not just the smell of the sea lions on the rocky bluffs," said Steve Haskins, the former president of the La Jolla Town Council. "Now it’s actually the sea lions taking over the stairways, sometimes they don’t let people go to the beach or leave the beach because you have very large male sea lions on the stairways, which can be very aggressive."Pollution from sea lion and bird droppings in the ocean also led to the cancellation of the annual La Jolla Rough Water Swim race this year, said Haskins.La Jolla Cove was under a health advisory warning for about two weeks in May due to high levels of pollution. Historically, advisories average two days in the cove, according to county staff.Over the years, a number of creative ideas to address the stench have been proposed. In 2013 the city began the application of a bioactive product on the bluffs. Early this year, a group of La Jolla residents and business owners suggested setting up rotating plastic cylinders that will roll the marine mammals off the rocks as they try to jump out of the water.Haskins said no action on that plan was taken.Now he is suggesting the city spray water on the sea lions, which the animals don't like, to remove them off the beach. Haskins said this solution would require no approval from authorities, and the city could do it immediately.The city commissioned a report on the sea lions that was supposed to come out in May, according to Haskins, but it hasn't yet been published.Mayor Kevin Faulconer's office did not immediately respond to a request for comment.

Read the original post: http://www.kpbs.org/

3/2/16 3/2/16

Sea Lion Die-Off Tied to 'Junk Food' Fish

A barking California sea lion pup shows signs of undernourishment.

Record numbers of California sea lion pups have been starving and stranding on beaches by the thousands in recent years, and now new research finds that a decline in their mothers’ food quality is behind the disturbing trend.

High calorie sardines and anchovies are now harder for sea lion moms to find, causing them to eat more rockfish and market squid that can be great for people on diets, but aren’t as hearty a meal for hungry sea lions. The findings are published in the journal Royal Society Open Science.“For human consumption, highly oily fish may actually be less desirable to consumers,” lead author Sam McClatchie told Discovery News. “In contrast, for predators with high energy demands, such as nursing female sea lions, eating fish with higher energy density due to higher content of calories and fats provides a more effective way to meet their nutritional demands.”Human demand for anchovies, in particular, has been on the rise due to the savory fish’s popularity in Caesar salad dressing and in “junk foods” like pizza. The real junk food for breeding female sea lions, minus the high calories, turns out to be the other types of fish that are now more prevalent in their feeding areas off central California.McClatchie, an oceanographer at NOAA Fisheries Service’s Southwest Fisheries Science Center, and his team studied both the sea lion pup strandings and population trends for fish that adult sea lions eat. Data for the latter came from surveys that are conducted each summer off the coast of California.A perfect storm now appears to be in place that is hurting the sea lions. Due to conservation efforts, numbers of these marine mammals increased from about 50,000 40 years ago to around 340,000 now. No one knows what the historic populations were like, given that Native Americans also frequently hunted sea lions and there are no detailed sea lion population estimates prior to the 1970s.At a time when the sea lion population appears to be approaching what the researchers call its current “carrying capacity” for the region, sardine and anchovy numbers plummeted while market squid and rockfish abundance increased.Several researchers, such as marine biologist Malin Pinsky of Rutgers, have attributed this and prior dramatic fish population plunges to overfishing by humans. He and his team note that such collapses started to occur more frequently in sardines and anchovies after the advent of efficient fishing vessels and techniques following World War II. Anchovies and sardines are important to the pet food and fish oil industries, in addition to their other mentioned common uses.“Overfishing is a problem throughout the world and across all species, including slow-growing fish like sharks, many of which are in serious trouble,” said Pinsky. “But it turns out that fishery collapses are three times more likely in the opposite kinds of species — those that grow quickly.”

McClatchie and his team, however, believe that the problem is “environmental,” and not because of overfishing.

McClatchie and his team, however, believe that the problem is “environmental,” and not because of overfishing. This distinction is important, as federal regulators are planning to do an official stock assessment of anchovies in the fall and will consider updating the 25,000-ton rule that now limits catches.“Sardine and anchovy populations both show large inter-annual variability that is environmentally driven and prior to any fishing,” McClatchie said.Joshua Lindsay of the National Marine Fisheries Service told Discovery News that populations of anchovies, sardines and other small fish “are linked to prevailing environmental conditions. NMFS has been working to better understand these environmental processes driving fish populations as well as the diet linkages between forage fish species and higher order predators to enhance the ecosystem science used in our fisheries management.”Marc Mangel, a professor at both the University of California at Santa Cruz and the University of Bergen, says the study “will help refocus the discussion about the causes of sea lion declines. More importantly, in my opinion, it is a terrific example of how we can use marine mammals and birds as sentinels or samplers of the environment.”In the meantime, the short-term outlook for sea lions is worrisome, particularly for rescue centers that have been stretched to their limits. McClatchie and his colleagues say that they “expect repeated years with malnourished and starving sea lion pups,” but can’t predict when that will end.

Read the original post: http://news.discovery.com/

11/11/15 11/11/15

Sea Lion Surge Prompts High Tech Tracking, Hazing & Killings

Producer: Vince Patton Videographers: Nick Fisher, Todd Sonflieth, Michael Bendixen Editor: Greg Davis Associate Producer: Cassandra Profita Additional Photos & Video: Columbia River Inter-Tribal Fish Commission, Cassandra Profita

On the last day of the spring salmon season on the Columbia River, sport anglers spotted competition for the fish they want to catch.Half a dozen sea lions poked up their heads just beyond the reach of fishing lines.Fisherman David Hylton from Redmond said, “I think we need to get them out of this system because this is not their natural habitat. They don’t live here.”Historically, sea lions did not come up the Columbia. Lewis & Clark spotted harbor seals. Archaeologists confirm finding remains of seals but not sea lions as high up the river as Celilo Falls.However, a growing number of sea lions have made the Columbia a frequent stopping point since the 1980s.

A record number of sea lions estimated at more than 2500 smothered the docks in Astoria in the spring of 2015. Nick Fisher/Oregon Public Broadcasting

In 2015, sea lions set records. More than 2500 covered the docks in Astoria and surveys estimated nearly 5,000 in the lower Columbia River.West coast populations have risen from about 180,000 in the late 1990s to nearly 300,000 in 2015.Biologists, anglers and tribes all believe the sea lions are killing too many endangered salmon.Government observers spend months watching the sea lions.The official estimates predict sea lions eat from 3,00 to 5,000 salmon, though in 2015 that jumped to more than 8,000.Doug Hatch, biologist with the Columbia River Inter-Tribal Fish Commission concedes they really don’t know how many salmon are eaten by sea lions.“We know there’s a lot of sea lions in the river,” says Hatch, “but we don’t know what their predation rate is on salmon.”Tribal biologists are experimenting with a high tech means to find out.They have captured a handful of sea lions, glued a tracking device to their head and released them back to the river.

Biologists glued an accelerometer tag to the head of a sea lion in an attempt to track its body motions. Columbia River Inter-Tribal Fish Commission

Hatch compares the tag to a fitness tracker people wear on their wrists. The sea lion tags measure the unique motions of a sea lion’s head, particularly when they eat.Sea lions often thrash about, throwing their food.It’s not play. They’re breaking the salmon up into pieces easier for them to eat.

A sea lion thrashes its head, tossing the salmon it has caught to break it up smaller to eat. Nick Fisher/Oregon Public Broadcasting

“When they do that it’s a very unique, distinctive movement of shaking,” says Hatch. “We think we’ll be able to capture that on the accelerometer tag.”Perhaps those tracking tags will show how many fish each sea lion eats when observers are not around to watch.Learning how many salmon sea lions eat is more than an academic question. It directly affects how many more sea lions may be put to death in future years.“It’s been quite controversial,” says Robin Brown, the marine mammal program leader for the Oregon Department of Fish & Wildlife.Brown says if the Army Corps of Engineers said it planned to modify Bonneville Dam in a way that would kill an additional 5,000 salmon each year, “It would never be permitted. The same is true from our perspective for the California sea lion predation on threatened and endangered salmon.”Biologists received federal permission to take more extreme measures.CRITFC helps with the first stage. They haze the animals by firing non-lethal noise-making shells from shotguns at sea lions near Bonneville Dam. The hazing lasts several months a year.

A Columbia River Inter-Tribal Fish Commission worker hazes sea lions with noise makers from a shotgun. Nick Fisher/Oregon Public Broadcasting

ODFW has regularly branded thousands of sea lions for the last several decades. The brands are large enough to be read by observers.If an individual sea lion has been exposed to non-lethal hazing and has been identified repeatedly eating salmon near the dam, that sea lion can be killed.That infuriates Ninette Jones, an activist with the Sea Lion Defense Brigade.Day after day, she arrives before dawn to watch and shoot video of the government’s sea lion trapping operation from the opposite side of the river.

Government biologists take select sea lions from traps to be euthanized at Bonneville Dam. Todd Sonflieth/Oregon Public Broadcasting.

Jones believes sea lions are scapegoats when the impact of dams kills far more fish.“We still had a million Chinook cross this dam. With our sea lions, with all the people, I think that’s pretty amazing,” says Jones. “For land mammals (humans) to allocate all the aquatic animals food source for themselves, I find that rather greedy.”In eight years, the government has killed 85 sea lions and transferred another 15 to zoos.Hatch, the CRITFC biologist, says he hopes their tracking tags will improve data showing whether sea lions are responsible for a substantial impact on salmon runs.“It’s circumstantial,” says Hatch. “You have a large population of sea lions and you have this loss of fish. But we need a predation rate. We need a way to link those together before we could say, without a doubt that it’s a sea lion problem.”Recent salmon runs in the millions have set records.But tribal and government biologists believe allowing several thousand fish each year to disappear to predators still poses too great a risk to the salmon.“None of us like the idea of having to kill animals, remove predators,” says Brown.ODFW says it has no plans to remove large numbers of sea lions; it will target only those individuals identified as repeatedly eating salmon near the dam.

Read the original post: http://www.opb.org/

6/9/15 6/9/15

Sea lions not leaving Port of Astoria anytime soon

by Stephanie Yao Long

Click here for: Photos | Video

The saga continues for Port of Astoria officials in what to do with the dozens of sea lions that are lounging around on their docks.In case you missed it last week, a motorized fiberglass orca was brought down from Bellingham, Washington in an attempt to scare away the barking beasts.First, mechanical problems halted its use, then it was tipped over in the wake of a passing ship and started taking on water.The fake orca is gone now, but the sightseeing humans are still flocking to the area to watch the sea lions basking in the sun.The tolerance for the invaders varies. Some neighbors don't mind the animals' noisy communication. Fishermen see the sea lions stealing up to 75% of their catch according to an earlier account.The Associated Press says:"Sea lion numbers along the West Coast have grown sharply since they were protected under a 1972 federal law. The sea lions that have been taking over docks at the Port of Astoria are attracted by runs of a fish known as smelt, federal biologists say."Officials have tried just about everything to keep the sea lions away — including beach balls, colorful tape, chicken wire and electrified mats.

Read the original post: oregonlive.com