Global warming today mirrors conditions leading to Earth’s largest extinction event, UW study says

A melting iceberg floats along a fjord leading away from the edge of the Greenland ice sheet near Nuuk, Greenland, in 2011. By this century’s end, if emissions continue at their current pace, humans will have warmed the ocean about 20 percent as much as during the Permian extinction event, newly published research says. (Brennan Linsley / The Associated Press)

If humans continue to pump greenhouse gases at our current rate, “we have no reason to think it wouldn’t cause a similar type of extinction,” said Curtis Deutsch, a UW professor and author of the research.

More than two-thirds of life on earth died off some 252 million years ago, in the largest mass extinction event in Earth’s history.

Researchers have long suspected that volcanic eruptions triggered “the Great Dying,” as the end of the Permian geologic period is sometimes called, but exactly how so many creatures died has been something of a mystery.

Now scientists at the University of Washington and Stanford believe their models reveal how so many animals were killed, and they see frightening parallels in the path our planet is on today.

Models of the effects of volcanic greenhouse-gas releases showed the earth warming dramatically and oxygen disappearing from its oceans, leaving many marine animals unable to breathe, according to a study published Thursday in the peer-reviewed journal Science. By the time temperatures peaked, about 80 percent of the oceans’ oxygen, on average, had been depleted. Most marine animals went extinct.

The researchers tested the model’s results against fossil-record patterns from the time of the extinction and found they correlated closely. Although other factors, like ocean acidification, might have contributed some to the Permian extinction, warming and oxygen loss account for the pattern of the dying, according to the research.

By this century’s end, if emissions continue at their current pace, humans will have warmed the ocean about 20 percent as much as during the extinction event, the researchers say. By 2300, that figure could be as high as 50 percent.

“The ultimate, driving change that led to the mass extinction is the same driving change that humans are doing today, which is injecting greenhouse gases into the atmosphere,” said Justin Penn, a UW doctoral student in oceanography and the study’s lead author.

Curtis Deutsch, a UW associate professor of oceanography and an author of the research, said if society continues to pump greenhouse gases at our current rate, “we have no reason to think it wouldn’t cause a similar type of extinction.”

Massive eruptions

The earth 252 million years ago was a much different place. The continents as we know them today were still mostly one landmass, named Pangea, which looks like a chunky letter “C” on a map.

The climate, however, resembled Earth’s now, and researchers believe animals would have adapted many traits, like metabolism, that were similar to creatures today. Nearly every part of the Permian Ocean, before the extinction, was filled with sea life.

“Less than 1 percent of the Permian Ocean was a dead zone — quite similar to today’s ocean,” Deutsch said.

The series of volcanic events in Siberia that many scientists believe set off the mass extinction “makes super volcanoes look like the head of a pin,” said Seth Burgess, a geologist and volcanologist with the United States Geological Survey.

“We’re talking about enough lava erupted onto the surface and intruded into the crust to cover the area of the United States that if you looked at the U.S. from above was maybe a kilometer deep in lava,” he said.

Burgess, who has researched the Siberian Traps volcanic events but did not work on the new Science paper, said scientists believe magma rising from the earth released some extinction-causing greenhouse gases.

In addition, sills of magma still inside the earth heated massive deposits of coal, peat and carbonate minerals, among others, which vented even more carbon and methane into the atmosphere.

“That’s how you drive the Permian mass extinction, by intruding massive volumes of magma into a basin rich in carbon-bearing sediments,” he said.

The UW and Stanford research “takes the next step in figuring out why things died at the end of the Permian,” Burgess said. “It couples what we think was happening in the climate with the fossil record, and it does it elegantly.”

Animals couldn’t breathe

It took a supercomputer more than six months to simulate all the changes the volcanic eruptions are suspected of causing during the Permian period. The computer models go into remarkable detail — simulating things like clouds, ocean currents and marine plant life — in describing what temperatures and conditions were like on Earth.

The researchers knew that surface temperatures rose about 10 degrees Celsius in the tropics because of previous scientific analysis of the fossilized teeth of eel-like creatures called conodonts.

To run their model, researchers pumped volcanic greenhouse gases into their simulation to match temperature conditions at the end of the Permian period.

As temperatures climbed toward the 10-degree mark, the model’s oceans became depleted of oxygen, a trend scientists are evaluating in today’s oceans, too.

To measure how rising temperatures and less oxygen would affect animal species of the Permian period, the researchers used 61 modern creatures — crustaceans, fish, shellfish, corals and sharks. The researchers believe these animals would have similar temperature and oxygen sensitivities to Permian species because the animals adapted to live in similar climates.

Warming’s effects were twofold on the creatures, the researchers found. In warmer waters, animals need more oxygen to perform bodily functions. But warm waters can’t contain as much dissolved oxygen, which means less was available to them.

In other words, as animals’ bodies demanded more oxygen, the ocean’s supply dropped.

In their model, the researchers were able to quantify the loss of habitat as species faced increasingly challenging ocean conditions. Surface-temperature rise and oxygen loss were more substantial in areas farther from the equator. Extinction rates also increased at higher latitudes.

Animals in the tropics were already accustomed to warmer temperatures and lower oxygen levels before the volcanic eruptions shifted the climate, according to the research. As the world warmed, they could move along with their habitat.

Marine creatures that favored cold waters and high oxygen levels fared worse: They had nowhere to go.

“The high latitudes where it’s cold and oxygen is high — if you’re an organism that needs those kind of conditions to survive, those conditions completely disappear from Earth,” Deutsch said.

In modern oceans, warming and oxygen loss have also been more pronounced near the poles, researchers said, drawing another analogue between the shift in climate some 252 million years ago and what’s happening today.

“The study tells us what’s at the end of the road if we let climate [change] keep going. The further we go, the more species we’re likely to lose,” Deutsch said. “That’s frightening. The loss of species is irreversible.”

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

Evan Bush: 206-464-2253 or ebush@seattletimes.com; on Twitter: @EvanBush.

Arctic Report Card Shows ‘Most Unprecedented Transition in History’

Arctic Report Card: Update for 2018 – Tracking recent environmental changes, with 14 essays prepared by an international team of 81 scientists from 12 different countries and an independent peer-review organized by the Arctic Monitoring and Assessment Programme of the Arctic Council. See https://www.arctic.noaa.gov/Report-Card

 

Those are two takeaways from the 2018 Arctic Report Card, which was released Tuesday at the American Geophysical Union conference in Washington, D.C. The 13th year of this peer-reviewed report card features 14 essays by 81 scientists from 12 countries.

Few places will feel the blight of climate change as hard as the Arctic. Our upper pole is warming faster than any other region on Earth, a trend that may be tied to erratic weather patterns across the northern hemisphere.

For the first time, the report card includes a warning about red tide and harmful algal blooms, which are expanding due to a lack of ice and warming ocean temperatures. Toxins from these micro-organisms are threatening marine wildlife and coastal fisheries, imperilling communities that depend on these species.

This year will also enter the record books as the second warmest for the Arctic since 1900, said Emily Osborne of the NOAA Arctic Research Program.

“The only warmer year occured in 2016,” Obsorne said, adding that Arctic air temperatures for the past five years have exceeded all records since the beginning of the 20th century. “The Arctic is experiencing the most unprecedented transition in history.”

Here are three things you need to know about the Arctic Report Card.

Red tide

When you hear about harmful algal blooms, the mind typically wanders to Florida, where thick scums of blue-green algae and clouds of red tide have floated in the state’s warm waters for more than a year.

Due to a warming Arctic Ocean, at least five families of these harmful micro-organisms are now present in other northern waters, like the Chukchi and Bering seas.

“The vast majority of the Arctic ocean has experienced clear long- term trends of warming,” said Karen E. Frey, a geographer and biogeochemist at Clark University in Worcester, Massachusetts. Microscopic creatures are thriving in these waters. Near St. Lawrence Island, for instance, west of the Alaska mainland, aquatic biomass in 2018 increased between 275 and 500 percent relative to the average over the last 14 years.

These harmful algal blooms produce a range of toxins, which can poison other plankton, fish, shellfish, birds and humans. One study of stranded marine mammals — like whales and seals — found the algal toxin domoic acid in all species tested.

Mounting microplastics

This explosion in tiny creatures has been paralleled by the rapid rise of microplastics in the Arctic Ocean. The Arctic Basin contains more microplastic than all other ocean basins in the world, according to a study published in June and cited in the report card, with the highest concentrations stuck in the Beaufort Sea.

These microplastics have made multiple intrusions into the food web, being found in everything from polar cod and seafloor-hugging invertebrates to Arctic birds. The plastic waste has also been found buried in sea ice, which scientists are using to study its abundance.

The major sources of these microplastics remain unclear. They could be floating to the Arctic from other oceans, but some contribution is due to waste like fishing nets and other gear from shipping activities, which have increased substantially since 2009.

The greening of the Arctic continues to gradually grow. Vegetation has expanded overall in the Arctic for the last 36 years, according to the new report card. As shrubs and grasses expand, some species of birds and mammals are thriving. Caribou and wild reindeer, both herbivores, are not part of this lucky class.

Despite growing food sources overall, caribou and wild reindeer are dying

Arctic caribou in North America and Greenland and reindeer in Russia and Norway have declined 56 percent over the last two decades, with their populations dropping from 4.7 million to 2.1 million. Why?

Increased drought and longer spans of hotter weather are causing outbreaks of infectious bacteria and parasites, said Howard Epstein, an ecologist at the University of Virginia. The caribou and reindeer populations are also declining due to a boon in predators and because extreme weather events are occasionally triggering droughts.

Wacky weather and the eviction of older ice

The Arctic pattern most pertinent to our daily lives, here in North America, revolves around warmth.

Warm air temperatures, which are increasing at twice the rate of the remaining world, continue to disrupt the polar jet stream, making it sluggish and unusually wavy. A surge of warm Arctic weather in 2017 coincided with severe winter storms in the eastern United States at the beginning of 2018 and a cold snap in Europe in March. Osborne said the jury is still out on the strength of the connection between Arctic warming and wacky weather in the mid-latitudes, but at the moment, the correlation is solid.

This atmospheric warming also drove declines in Arctic snow cover and caused melting of the Greenland ice sheet. But the biggest loser, in terms of frozen water, is Arctic sea ice. Older packs of Arctic sea ice, which used to be impervious to the annual melting cycle, are thinner and covering less area than they have in the past. The oldest ice has declined by 95 percent in the last 33 years.

“During two weeks in February, which is typically the height of ice growth, the Bering Sea lost a piece of ice the size of Idaho,” said Donald Perovich, a sea ice geophysicist at Dartmouth College in New Hampshire. March witnessed the second lowest sea ice extent in 39 years.

Perovich said this loss is being felt hardest by coastal communities, which used to be buffered by the sea ice. The loss is also exposing communities to massive storm surge and disappearing shorelines. It is also depriving coastal residents of a safe route for hunting and travel.

“In 2018, the effects of persistent Arctic warming continue to mount … pushing the Arctic into unchartered territory,” Obsorne added.

Original post: https://www.kqed.org/

‘Get the balance back’: Amid seal and sea lion boom, group calls for hunt on B.C. coast

Quickest way to reverse declining salmon stocks is to introduce a harvest: Pacific Balance Pinnipeds Society

Greg Rasmussen · CBC News · Posted: Dec 01, 2018 1:00 AM PT

For the first time in decades, a small-scale seal hunt is taking place on Canada’s West Coast — all in the hopes that it leads to the establishment of a commercial industry to help control booming seal and sea lion populations and protect the region’s fish stocks.

In early November, a group called the Pacific Balance Pinnipeds Society (PBPS) started using First Nations hunting rights as part of a plan to harvest 30 seals. The society plans to test the meat and blubber to see if it’s fit for human consumption and other uses.

“We can look at opening up harvesting and starting a new industry,” said Tom Sewid, the society’s director and a commercial fisherman. “Since the [West Coast] seal cull ended in the 1970s, the population has exploded.”

Sewid, who is a member of the Kwakwaka’wakw First Nation, points out that Indigenous people have hunted the animals for thousands of years. Recent decades with little or no hunting have been an anomaly, he said, pointing to research that shows seal numbers are even higher now than in the 1800s.

Out go the nets, in come the sea lions

What’s become an ongoing battle between humans and sea lions played out on a recent nighttime fishing expedition, when Sewid and a crew of commercial fishermen set out in a 24-metre seine boat to fish for herring off the coast of Parksville, B.C.

The crew’s goal was to catch about 100 tonnes of herring, which rise to the surface to feed after dark. But the faint barking of sea lions was soon heard over the thrum of the boat’s diesel engine.

“All them sea lions out there are all happy — [they’re] all yelling, ‘Yahoo, it’s dinner time!'” Sewid said.

Once the crew spotted the herring, they let out hundreds of metres of net, while a smaller boat helped to circle it around the huge mass of fish. The crew then closed the bottom of the net, capturing the herring.

Watch sea lions pillage fishermen’s nets:

But the catch also provided some uninvited visitors with a captive dinner: Dozens of sea lions jumped over the floats holding up the net and started to gorge.

“These guys, it’s just a buffet for them,” said Sewid, as the bodies of the sea lions glistened in the boat’s floodlights. “Just like pigs at a trough.”

Sewid said the sea lions have learned there’s an easy meal to be had whenever they see or hear the fishing boats.

“They’re not afraid of us. They’ve habituated themselves to seeing that humans and fishing equates easy access to food, which is not right,” he said. “The animal kingdom is not supposed to be like that.”

Restarting a banned hunt

The hunting of seals and sea lions — which are collectively known as pinnipeds — has been banned on the West Coast for more than 40 years. It’s one reason their numbers have exploded along the entire Pacific coastline of North America.

According to one study, the harbour seal population in the Salish Sea is estimated at 80,000 today, up from 8,600 in 1975. The study also says seals and sea lions now eat six times as many chinook salmon as are caught in the region’s commercial and sports fisheries combined.

That adds up to millions of tonnes of commercially valuable fish.

Sewid’s group is proposing to cull current populations of harbour seals and sea lions by half, which would see thousands of the animals killed each year.

Tom Sewid is leading the effort to secure what he calls a sustainable harvest of seals and sea lions along the B.C. coast. (Greg Rasmussen/CBC)

The society’s small-scale “test” harvest is taking place between B.C.’s southern Gulf Islands and as far north as Campbell River, on Vancouver Island. It’s being carried out under the provisions of the Aboriginal Fisheries Strategy, which gives some First Nations harvesting and management rights for food and ceremonial purposes.

Testing the meat to see if it’s safe for human consumption is a first step in a plan to eventually gain permission for what the PBPS envisions as a sustainable, humane commercial hunt, which would largely be carried out by coastal First Nations.

“All the meat that’s in there, you’re looking at the high-end restaurants [that would sell it],” Sewid said. “The hides can also be used.”

Seal blubber is particularly valuable, he said, because it can be rendered down into an oil that’s in demand because of its high Omega-3 fatty acid content.

Watch fishing crew struggle to free sea lions entangled in their nets:

One of the biggest hurdles facing the group is convincing the federal Department of Fisheries and Oceans to open a commercial hunt on the West Coast.

The seal hunt that takes place in the Atlantic and Arctic is controversial, and has long been subject to protests and fierce opposition from animal rights groups. The group expects a West Coast harvest to also face fierce confrontations.

Canadian Inuit have been waging a counter-campaign, highlighting the importance of the animal and the longstanding tradition of their hunt.

Most Canadian seal products are also banned in Europe and a handful of other countries, but the society says demand is strong in Asia.

Supporters and opponents

The PBPS does have a growing list of supporters, including 110 First Nations groups, a number of commercial fishing organizations, and some sectors of B.C.’s economically important sport fishing sector.

However, one key player, the Sport Fishing Institute of B.C., opposes a large commercial hunt, fearing it would generate public outrage and might not achieve the goal of enhancing fish stocks.

The institute’s director, Martin Paish, says the group sees some value in targeting some seals and other fish predators at specific times of year in a number of key river systems; he believes a limited hunt would help protect salmon stocks and boost the billion-dollar-a-year B.C. sport fishing industry.

“Our goal is to use predator control in a careful manner to improve chinook [salmon] production where it is needed,” said Paish.

Carl Walters is a fish biologist and UBC professor who supports cutting B.C.’s population of seals and sea lions by half. (Nic Amaya/CBC)

Fisheries scientist Carl Walters, a professor emeritus with UBC, believes culling the regions sea lions and seals could dramatically boost salmon stocks. He points to numerous studies showing how pinniped populations have been increasing, while salmon numbers have been plummeting.

“They’re killing a really high percentage of the small salmon shortly after they go into the ocean, about half of the coho smolts and a third of the chinooks,” he said.

Advocates of a hunt are also pitching it as a way to help B.C.’s endangered southern resident killer whales, which feed mainly on salmon.

“The thing that would benefit southern resident killer whales is to see improved survival of small chinook salmon — and I think the only way we can achieve that is by reducing seal numbers,” Walters said.

Peter Ross, from the Coastal Ocean Research Institute, says there would be little benefit to salmon from a seal and sea lion cull. (Nic Amaya/CBC)

Others disagree, including Peter Ross, the vice-president of research and executive director of the Coastal Ocean Research Institute.

“Killing of seals and sea lions is not going to have any positive impact for any salmon populations in coastal British Columbia,” he said.

While a few localized populations of salmon might benefit from a cull, Ross said climate change, habitat destruction and overfishing are all bigger factors in the overall decline of stocks.

Other subspecies of orcas, however, feed mainly on seals, so a hunt would reduce their access to prey.

Back on the boat, Sewid concedes a hunt would be controversial — but he firmly believes it’s necessary.

“All the indicators are there,” he said. “It’s time to get the balance back.”

The fishing crew from the Western Investor are shown harvesting herring in November. But they say they are being hampered by dozens of sea lions in their nets almost every night. (Nic Amaya/CBC)

Original post: https://www.cbc.ca/news/canada/british-columbia/seal-hunt-b-c-1.4921610