A lethal virus that killed tens of thousands of harbor seals in the northern Atlantic in 2002 suddenly spread to sea lions, seals and otters in the northern Pacific Ocean two years later, confusing scientists, as NBC News reported.
How could the pathogen that causes a measles-like disease in marine mammals that had only been found on the Atlantic coasts suddenly have spread to the Pacific?
"We didn't understand how a virus from the Atlantic ended up in these sea otters. It's not a species that ranges widely," said Tracey Goldstein, a scientist at the University of California Davis who investigates how pathogens move through marine ecosystems, as National Geographic reported.
Goldstein and her colleagues looked at 15 years of data and realized that the spike in the virus was commensurate with Arctic sea ice loss. The data, published in a new study in the journal Scientific Reports, finds that the loss of Arctic sea ice allowed otters and other mammals to move west and spread the virus. The study shows that global heating is opening new avenues for diseases to spread, as National Geographic reported.
"The loss of sea ice is leading marine wildlife to seek and forage in new habitats and removing that physical barrier, allowing for new pathways for them to move," said Goldstein in a press release. "As animals move and come in contact with other species, they carry opportunities to introduce and transmit new infectious disease, with potentially devastating impacts."
The rapid loss of sea ice is creating a fertile breeding ground for viruses as animals travel to areas they have never been before. The phenomenon was first observed 17 years ago.
"It was a perfect storm in 2002," said Goldstein, as NBC News reported. "It was the lowest ice year on record at the time, and at the same time, in August and September, there was a really large outbreak."
To study the outbreak, the researchers took blood and mucous samples from seals, sea lions and otters from arctic and subarctic areas, from southeast Alaska to Russia. The swab samples allowed the scientists to determine which populations had been infected with the Phocine distemper virus, or PDV, and which specific strain they had been exposed to, as NBC News reported.
PDV is a common canine virus that vets vaccinate for. It spreads easily when an animal comes into direct contact with an infected animal. The virus manifests in seals much like the canine version does in dogs — goop discharged from the eyes and nose and a fever. With marine mammals, it also leads to erratic swimming, according to National Geographic.
"The virus has been shown to spread pretty easily between marine mammals," said Shawn Johnson, the vice president of veterinary medicine at The Marine Mammal Center in Sausalito, California to National Geographic. Since so many marine mammals migrate north, "the Arctic could be a perfect melting pot for transmission of the disease," Johnson said.
Not only is the changing landscape of the Arctic allowing animals to travel further, animals that need to travel farther for food will experience extra stress and exhaustion, which will weaken their immune systems and leave them susceptible to disease, Goldstein told National Geographic.
The study adds to a growing body of research signaling trouble for marine mammals, including an increase in marine heat waves that deplete their food supply and an increase in toxic algal blooms that can infect fish with a toxin that causes brain damage in marine mammals, as NBC News reported.
"When we see these changes happening in animals, we can't ignore them, because the impacts on people and the planet are not far behind," said Elizabeth VanWormer, the study's lead author, as NBC News reported. "This shows how interconnected these things are — the health of people, animals and the planet."
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On Friday, Seal Rescue Ireland released Sesame the seal into the ocean after five months of rehabilitation at the Seal Rescue Ireland facility. Watch the release on EcoWatch's Facebook.
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From coral bleaching to ocean acidification, the pumping of carbon dioxide into the atmosphere and the resulting climate change is a major problem for the world's marine life. And just last week, a study revealed that the world's oceans have absorbed 60 percent more heat than previously thought.
Researchers think a mysterious die-off of seals along the Maine coast could be linked to chemical pollution, the Portland Press Herald reported Sunday.
More than 400 dead or stranded seals have washed up on the Maine coast so far this year, more than in any of the past seven years, according to National Oceanic and Atmospheric Administration (NOAA) statistics.
Tackling plastic pollution is the theme of 2018. Stories of animals dying from ingesting plastic are all around the web. Did you ever think that the plastic packaging used for your groceries might be the cause of death for an animal species you love?
A young harp seal that washed up dead on the Scottish Isle of Skye last Friday likely died of health complications after ingesting a small piece of plastic wrap, according to scientists who examined the animal.
Scientists with the Scottish Marine Animal Strandings Scheme (SMASS) performed a necropsy on the animal and described it as an "unusual case" in a Facebook post Wednesday. First, Scotland is outside of the normal range for the Arctic harp seal. Secondly, death from plastic ingestion is rare for seals.
Scientists studying the warming waters and salinity of the Southern Ocean's Amundsen Sea—which surrounds the Thwaites and Pine Island glaciers, two of the largest and fastest-retreating glaciers in Antarctica—are using a novel method to collect data.
They temporarily glued sensors onto the fur of Antarctic seals. Really.
Following a £10 million ($13.5 million) eradication scheme and nearly a decade of work, South Georgia was officially declared rodent-free on Tuesday, the first time since humans arrived on the island more than 200 years ago.
The British territory is one of the world's last great wildlife areas. There you'll find 98 percent of the world's Antarctic fur seals, half the world's elephant seals and four species of penguins—including King Penguins with around 450,000 breeding pairs. The birdlife includes albatrosses, prions, skua, terns, sheathbills and petrels.
Governments around the world are waking up to the scourge of plastics on our oceans and its creatures by banning items such as shopping bags and drinking straws. But an often-overlooked form of plastic waste is also a major threat to our seas: "ghost" gear.
A report released Thursday from World Animal Protection highlights that every year 640,000 metric tons of fishing nets are lost or discarded in our oceans each year, trapping and killing countless marine mammals, including endangered whales, seals and turtles. Shallow coral reef habitats also suffer further degradation from the gear, which can take up to 600 years to decompose.
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By Amy McDermott
At 5 a.m. one morning last spring, a baby seal wandered into the sleepy town of Bar Harbor, Maine. The little pup waddled off the beach and onto the highway. Locals called the police. The police called Rosemary Seton.