Scientists say the die-off, which is entering its third year, is likely due to a scarcity of food in the animals’ cold water feeding grounds

Three adult gray whales photographed via drone in 2017, 2018 and 2019 in Laguna San Ignacio off the coast of Mexico. The three shots show increasingly skinny whales, a bad sign for an animal that needs to make a 10,000-mile return trip to reach its feeding grounds.

Reports of emaciated gray whales have started to come in as the whales arrive at their breeding grounds off of Baja California, Mexico. If the trend continues this will be the third hard year in a row for the North Pacific gray whale population, with hundreds turning up dead in what scientists are calling an unusual mortality event, reports Isaac Schultz for Gizmodo.

According to new research published this week in the journal Marine Ecology Progress Series, the die-off began in January 2019 and as of the paper’s publication, the official death toll stood at 378. The species’ last unusual mortality event occurred around the year 2000 and claimed the lives of some 600 whales, according to Gizmodo.

Every winter the gray whales of the North Pacific head some 10,000 miles south from their cold water feeding grounds in the Bering, Chukchi and Arctic seas to breed off the more hospitable but less bountiful waters off Southern California and Mexico, reports Chrissy Sexton for Earth.com.

To build up the fat reserves the whales need to survive and successfully reproduce during their stay in the balmy southern climes, they have to feed non-stop from May until October. If the whales can’t eat enough to pack on a thick layer of blubber, it can spell doom for the marine mammals, who may die en route to their breeding grounds or lack the energy reserves to make the return trip, according to a statement.

“It appears that a large number of gray whales are leaving their feeding grounds already in a poor nutritional state and by the time they have completed the breeding season in Mexico they have depleted their energy reserves and starve to death,” says Fredrik Christiansen, a whale researcher at Aarhus University and co-author of the research, in the statement.

Researchers aren’t sure exactly what’s causing the current bout of starvation, but the authors of the paper suggest that the simplest explanation may be a scarcity of food in the Bering Sea, per Gizmodo. As for what might be behind a scarcity of food, it’s hard to ignore how climate change has wrenched the whales’ feeding grounds. Both the Bering Sea and the Chukchi Sea have been hit with record low extents of sea ice and record high ocean temperatures in recent years.

To reach their conclusions Christiansen and his co-authors made aerial observations of gray whales using drones beginning in 2017. The researchers made systematic assessments of the whales’ size and fat stores using these photos and found that beginning in 2019 the whales started to slim down.

“What stood out in this case was that we had emaciated juveniles and adults,” Christiansen tells Gizmodo. “That’s not normal.”

In a separate research paper released last week, scientists with the National Oceanic and Atmospheric Administration (NOAA) said that the North Pacific gray whale population as a whole has shrunk by nearly 25 percent since 2016, the Associated Press reports. NOAA researchers counted roughly 6,000 fewer whales last January, for a total of 21,000, compared to 2016 when they saw 27,000.

Though the numbers may sound dire, NOAA tells the AP that this die-off isn’t outside the bounds of normalcy. Instead, it could be a sign that the number of whales simply exceeded what the marine environment could support and doesn’t indicate a long-term threat to the whales’ survival.

https://www.smithsonianmag.com/smart-news/nearly-400-gray-whales-have-died-west-coast-2019-180976847/

PermeateFree said:

Scientists say the die-off, which is entering its third year, is likely due to a scarcity of food in the animals’ cold water feeding grounds

Three adult gray whales photographed via drone in 2017, 2018 and 2019 in Laguna San Ignacio off the coast of Mexico. The three shots show increasingly skinny whales, a bad sign for an animal that needs to make a 10,000-mile return trip to reach its feeding grounds.

Reports of emaciated gray whales have started to come in as the whales arrive at their breeding grounds off of Baja California, Mexico. If the trend continues this will be the third hard year in a row for the North Pacific gray whale population, with hundreds turning up dead in what scientists are calling an unusual mortality event, reports Isaac Schultz for Gizmodo.

According to new research published this week in the journal Marine Ecology Progress Series, the die-off began in January 2019 and as of the paper’s publication, the official death toll stood at 378. The species’ last unusual mortality event occurred around the year 2000 and claimed the lives of some 600 whales, according to Gizmodo.

Every winter the gray whales of the North Pacific head some 10,000 miles south from their cold water feeding grounds in the Bering, Chukchi and Arctic seas to breed off the more hospitable but less bountiful waters off Southern California and Mexico, reports Chrissy Sexton for Earth.com.

To build up the fat reserves the whales need to survive and successfully reproduce during their stay in the balmy southern climes, they have to feed non-stop from May until October. If the whales can’t eat enough to pack on a thick layer of blubber, it can spell doom for the marine mammals, who may die en route to their breeding grounds or lack the energy reserves to make the return trip, according to a statement.

“It appears that a large number of gray whales are leaving their feeding grounds already in a poor nutritional state and by the time they have completed the breeding season in Mexico they have depleted their energy reserves and starve to death,” says Fredrik Christiansen, a whale researcher at Aarhus University and co-author of the research, in the statement.

Researchers aren’t sure exactly what’s causing the current bout of starvation, but the authors of the paper suggest that the simplest explanation may be a scarcity of food in the Bering Sea, per Gizmodo. As for what might be behind a scarcity of food, it’s hard to ignore how climate change has wrenched the whales’ feeding grounds. Both the Bering Sea and the Chukchi Sea have been hit with record low extents of sea ice and record high ocean temperatures in recent years.

To reach their conclusions Christiansen and his co-authors made aerial observations of gray whales using drones beginning in 2017. The researchers made systematic assessments of the whales’ size and fat stores using these photos and found that beginning in 2019 the whales started to slim down.

“What stood out in this case was that we had emaciated juveniles and adults,” Christiansen tells Gizmodo. “That’s not normal.”

In a separate research paper released last week, scientists with the National Oceanic and Atmospheric Administration (NOAA) said that the North Pacific gray whale population as a whole has shrunk by nearly 25 percent since 2016, the Associated Press reports. NOAA researchers counted roughly 6,000 fewer whales last January, for a total of 21,000, compared to 2016 when they saw 27,000.

Though the numbers may sound dire, NOAA tells the AP that this die-off isn’t outside the bounds of normalcy. Instead, it could be a sign that the number of whales simply exceeded what the marine environment could support and doesn’t indicate a long-term threat to the whales’ survival.

https://www.smithsonianmag.com/smart-news/nearly-400-gray-whales-have-died-west-coast-2019-180976847/

That’s not what I would expect at all. It’s a worry.

Climate change has greatly increased the number of plankton organisms in whale feeding grounds around the world. That includes on both sides of the Kamchatka Peninsula, so probably the Bering Sea as well. But that doesn’t mean that it has increased the right species of plankton, or at the right time of the year.

mollwollfumble said:

PermeateFree said:

Scientists say the die-off, which is entering its third year, is likely due to a scarcity of food in the animals’ cold water feeding grounds

Three adult gray whales photographed via drone in 2017, 2018 and 2019 in Laguna San Ignacio off the coast of Mexico. The three shots show increasingly skinny whales, a bad sign for an animal that needs to make a 10,000-mile return trip to reach its feeding grounds.

Reports of emaciated gray whales have started to come in as the whales arrive at their breeding grounds off of Baja California, Mexico. If the trend continues this will be the third hard year in a row for the North Pacific gray whale population, with hundreds turning up dead in what scientists are calling an unusual mortality event, reports Isaac Schultz for Gizmodo.

According to new research published this week in the journal Marine Ecology Progress Series, the die-off began in January 2019 and as of the paper’s publication, the official death toll stood at 378. The species’ last unusual mortality event occurred around the year 2000 and claimed the lives of some 600 whales, according to Gizmodo.

Every winter the gray whales of the North Pacific head some 10,000 miles south from their cold water feeding grounds in the Bering, Chukchi and Arctic seas to breed off the more hospitable but less bountiful waters off Southern California and Mexico, reports Chrissy Sexton for Earth.com.

To build up the fat reserves the whales need to survive and successfully reproduce during their stay in the balmy southern climes, they have to feed non-stop from May until October. If the whales can’t eat enough to pack on a thick layer of blubber, it can spell doom for the marine mammals, who may die en route to their breeding grounds or lack the energy reserves to make the return trip, according to a statement.

“It appears that a large number of gray whales are leaving their feeding grounds already in a poor nutritional state and by the time they have completed the breeding season in Mexico they have depleted their energy reserves and starve to death,” says Fredrik Christiansen, a whale researcher at Aarhus University and co-author of the research, in the statement.

Researchers aren’t sure exactly what’s causing the current bout of starvation, but the authors of the paper suggest that the simplest explanation may be a scarcity of food in the Bering Sea, per Gizmodo. As for what might be behind a scarcity of food, it’s hard to ignore how climate change has wrenched the whales’ feeding grounds. Both the Bering Sea and the Chukchi Sea have been hit with record low extents of sea ice and record high ocean temperatures in recent years.

To reach their conclusions Christiansen and his co-authors made aerial observations of gray whales using drones beginning in 2017. The researchers made systematic assessments of the whales’ size and fat stores using these photos and found that beginning in 2019 the whales started to slim down.

“What stood out in this case was that we had emaciated juveniles and adults,” Christiansen tells Gizmodo. “That’s not normal.”

In a separate research paper released last week, scientists with the National Oceanic and Atmospheric Administration (NOAA) said that the North Pacific gray whale population as a whole has shrunk by nearly 25 percent since 2016, the Associated Press reports. NOAA researchers counted roughly 6,000 fewer whales last January, for a total of 21,000, compared to 2016 when they saw 27,000.

Though the numbers may sound dire, NOAA tells the AP that this die-off isn’t outside the bounds of normalcy. Instead, it could be a sign that the number of whales simply exceeded what the marine environment could support and doesn’t indicate a long-term threat to the whales’ survival.

https://www.smithsonianmag.com/smart-news/nearly-400-gray-whales-have-died-west-coast-2019-180976847/

That’s not what I would expect at all. It’s a worry.

Climate change has greatly increased the number of plankton organisms in whale feeding grounds around the world. That includes on both sides of the Kamchatka Peninsula, so probably the Bering Sea as well. But that doesn’t mean that it has increased the right species of plankton, or at the right time of the year.

The melting sea ice from below because of warming water is apparently smoothing the ice surface, so not forming a roughened surface where krill can collect and breed (loss of habitat).

PermeateFree said:

The melting sea ice from below because of warming water is apparently smoothing the ice surface, so not forming a roughened surface where krill can collect and breed (loss of habitat).

Ah. OK. That’s a plausible hypothesis.

Rachael Funnell
By Rachael Funnell
28 Jan 2021, 10:57

If you’ve seen Finding Nemo, you’ll be familiar with the surprisingly small prey consumed by some of the world’s biggest sea creatures (swim away!). To be fair, as a whale, you’re hard pushed to find prey items bigger than yourself so it stands to reason they have opted for gorging on bitesize snacks. Some feed on krill and plankton while others dine on fish, and dependent on their diet these animals have evolved to have teeth or plates that can filter tiny organisms from seawater.

An episode of David Attenborough’s new BBC series, A Perfect Planet, last week showed for the first time a bizarre and ingenious new feeding strategy employed by Eden’s whales in the Gulf of Thailand. Pollution from the land has begun to suffocate the waters here and it’s driven fish species to the surface where the oxygen concentration is naturally higher. Eden’s whales (Balaenoptera edeni edeni) lunge feed to scoop up these fish but they have to swallow lots of water to catch prey this way and when numbers are low it’s hardly worth the effort. Tired, it seems, of actively pursuing lunch, they’ve opted for an alternative approach called trap feeding which leaves the heavy lifting to its prey.

By opening their mouths at the surface like a giant basketball hoop, the whales can spook the fish making them leap into the air and straight into their mouth. During the making of the program, the team witnessed the behavior being practiced by lone whales and even mothers and calves, who benefited from having a partner to swim around and scare more fish into jumping into their gaping mouth. Amazingly, birds will even cash in on the feeding events by swooping down and grabbing fish from inside the whale’s mouth. It’s a rough deal for the oxygen-starved fish but a breathtaking example of how wild animals can learn to overcome anthropogenic-driven changes in the environment.

An incredible example of wildlife videography but as Daniel Rasmussen, an associate producer on the shoot, told IFLScience, it was a far from easy sequence to film. Even finding the animals proved tricky as murky water meant it was hard to locate them using drones and the whales’ sensitivity to noise meant they couldn’t use speedy boats.

“We were cursed with a very slow boat which made even finding the whales near impossible, and when you did spot them in the distance, you could pretty much set your direction and then lie down for a nap for two hours before you got there and even then they were inevitably gone,” said Rasmussen. The frustrating piece of kit was however a conscious choice, he explained, as most modern boats with exhausts in the water would cause too much of a din and scare off any whales they were tracking.

Armed with an older, more traditional Thai boat that exhausted into the air, the team’s progress was slow and while it was whisper-quiet below deck it was terribly noisy for those up top. As such, despite working two 3-week shoots over 2 years, the team saw just a handful of feeding events suitable for filming.

Reports from members of A Perfect Planet’s huge production team certainly give an idea of the difficulties faced in wildlife filmmaking, including this harrowing account from Matt Aeberhard who tackled the caustic soda flats of Lake Natron to film its flamingos. However, it seems all is forgiven of the natural world when you finally land that perfect shot – even if your means of celebration is limited.

“We were all incredibly excited to be eating Thai food on this trip, but on day one, we realised we had been given the same food for lunch as we had for breakfast, and then again the same for dinner,” said Rasmussen. “The next day was a repeat, and the next, and so it continued. By week three we had barely seen a whale, couldn’t talk to each other because the boat was so loud, and none of us wanted to eat anymore. So, when we finally filmed a successful trap feeding moment it was euphoric and we celebrated in the only way we could, by eating lunch.”

>video
https://www.iflscience.com/plants-and-animals/edens-whales-have-adapted-to-polluted-waters-with-awesome-new-feeding-strategy/