Animal tales: Orcas
Why these orcas are wearing salmon as hats (again): National Geographic
First observed in the 1980s, the fad of orcas swimming around with dead salmon on their foreheads off Washington State seemed to have faded—until now.
“It seemed to kind of pass along to multiple different members of the population,” says Deborah Giles, a longtime biologist at the University of Washington’s Friday Harbor Laboratories.
Animal tales: Orcas
Why these orcas are wearing salmon as hats (again): National Geographic
While the behavior started with a female in K-Pod, within a few months, the so-called “salmon hat” craze had spread to both J-Pod and L-Pod, eventually becoming prominent in all three pods that make up the population segment, or clan, known as the southern resident orcas. This clan of 71 individuals exclusively eat salmon.
Animal tales: Orcas
Why these orcas are wearing salmon as hats (again): National Geographic
But then, all at once, the headwear fad faded—until October 25, 2024, when photographer Jim Pasola captured an orca known as J27 Blackberry with a shiny silver fish laid across its dome.
While others have reported a handful of salmon-hat sightings over the decades, this one caught the internet's attention—perhaps because it was so excellently documented by Pasola’s photo.
At 32, Blackberry is too young to have seen the original salmon hat craze, but it’s possible the male learned the behavior from other members of the J-Pod, some of which were alive in 1987.
“These are incredibly smart animals,” says Giles, who has witnessed salmon hat behavior once in person. “The paralimbic portion of their brain is significantly more developed than it is even in humans, and these are parts of their brains that are associated with memory, and emotion, and language.”
Animal tales: Orcas
Why these orcas are wearing salmon as hats (again): National Geographic
What’s less known is why orcas are putting their dinner on their heads. Is it some mode of communication? A way to impress a potential mate? Or is it just a highly intelligent marine mammal goofing off? “It’s all speculation,” Giles says. “We don’t know.”
Southern resident orcas are an ecotype, or population adapted to a particular habitat. These Pacific Northwest animals eat only fish; other ecotypes in other parts of the world specialize in hunting sharks, for instance.
A steady decline in salmon species due to overfishing, dam construction, and other causes has landed the southern resident ecotype orca on the U.S. endangered species list.
But this fall, there’s an unusual bounty of chum salmon in Puget Sound. So it’s plausible these orcas can finally relax and have fun—such as playing with their food, says Giles, who is also the science and research director at the nonprofit Wild Orca.
In fact, the week Pasola took his photo, there was a rare, 10-day stretch of consecutive J-Pod sightings in the area. The idea also fits with a pattern researchers have noticed in this endangered population: When food is scarce, orcas spend more time foraging and less time resting and socializing.
Animal tales: Orcas
Why these orcas are wearing salmon as hats (again): National Geographic
Many human infatuations involve toys, and the same is true for orcas. Salmon hats are “one of several whale ‘fads’ that have come and gone over the years,” says Monika Wieland Shields, director of the Orca Behavior Institute in Washington. “Once it was spy-hopping with dead salmon draped over their [pectoral] fins, and another time it was pulling kelp underwater and letting it go so it would fly up above the surface.”
The recent phenomenon of orcas downing boats in the Strait of Gibraltar may also be a form of play or social learning. In each case, the behavior trended over the course of a season before fizzling out, says Shields, who isn’t convinced the salmon-hat trend has resurfaced. “In my opinion it's a stretch to say it was a salmon hat, and an even greater stretch to say the fad is back off a single photo,” she says.
Giles cautions “it’s quite possible that this has been part of their behavioral repertoire that they’ve been doing since time immemorial, and it was just noticed by humans in the ‘80s.” Whatever the cause, Giles says salmon hats are probably a positive development for these rare creatures. “If it is the case that they’re behaving in this way because they’re well-fed at the moment, I want to look at this as something to strive for.”
Animal tales: Dolphins
These dolphins have orca ‘friends.’ They may have an ulterior motive: National Geographic
Scientists have documented what might be the first case of friendly interactions between killer whales and smaller cetaceans. Here's what they think is going on.
A pod of Dall’s porpoises sped toward an adult orca, swimming under and around her for a few minutes before getting “bored” and moving on to her companions—a mother orca with a young calf. As soon as the porpoises appeared, the calf seems to have gotten excited, speeding up and trying to catch the porpoises. The mother eventually got frustrated, but “the calf looked like it was having a great time,” says Brittany Visona-Kelly, a whale biologist with Ocean Wise, a nonprofit conservation organization in Vancouver, Canada.
Eventually the mother’s annoyance boiled over into tail slaps on the surface of the water, but the porpoises didn’t pay much attention, hanging around for a few more minutes of play before taking off.
Animal tales: Dolphins
These dolphins have orca ‘friends.’ They may have an ulterior motive: National Geographic
Northern resident killer whales are found from the northern part of Vancouver Island and up the British Columbia Coast into southeastern Alaska, overlapping with the ranges of Dall’s porpoises and Pacific white-sided dolphins.
Northern resident orcas don’t have exclusive control over their range though—southern resident killer whales overlap parts of their southern range, while Bigg’s killer whales and other transient groups patrol up and down the coast. “[All three types of killer whales] are almost thought of as different species,” says Visona-Kelly.
In a study published recently in Ecology and Evolution, Visona-Kelly and her colleague Lance Barrett-Lennard analyzed 42 interactions between northern residents, Dall’s porpoises, and Pacific white-sided dolphins that they captured by drone between 2018 and 2021 in Johnstone Strait, between Vancouver Island and the British Columbia mainland.
These videos revealed dimly understood interactions that had previously only been observed by boat or shore.
Animal tales: Dolphins
These dolphins have orca ‘friends.’ They may have an ulterior motive: National Geographic
In these encounters, the dolphins and porpoises actively approached the northern residents. The videos showed the smaller cetaceans swimming with the orcas in formation—sometimes all three species at the same time. Porpoises and dolphins would also play with orca calves, usually for a few minutes but occasionally for more than an hour. Visona-Kelly and her colleague aren’t sure why the porpoises and dolphins did this, but they have a few theories.
One possibility is they use the northern residents, which feed on chinook salmon, as a shield against Bigg’s killer whales that prey on other marine mammals, including porpoises and dolphins. Even though their ranges overlap, Bigg’s typically avoid northern residents, which usually travel in larger groups. While visually similar, Visona-Kelly says that dolphins and porpoises may differentiate from the two by picking up on the northern residents’ chatter—Bigg’s rely typically on stealth and are quieter. It’s also possible that these smaller species might just be trying to get a closer look at a less threatening predator so they know what they are up against if attacked by Bigg’s orcas.
Rivers in the Sky (USGS, 2012)
https://www.usgs.gov/media/images/atmospheric-rivers-earth-jan-2012
Streams of water, with water vapor indicated by color, move over the globe, with atmospheric river plumes streaming away from the equator.
Rivers in the Sky
Atmospheric rivers transport water vapor from the tropics towards the poles.
The formation of an atmospheric river starts near the equator. The sun heats the earth most directly at the equator, and these warm temperatures cause water to evaporate and rise into the atmosphere.
Some of that water vapor is pulled away from the equator by atmospheric circulation, forming a narrow band that transports the water vapor to other regions like a conveyer belt. Atmospheric rivers flow in the lowest part of the atmosphere, only about half a mile to a mile above the ground. When they reach the coasts and flow inland over mountains, the atmospheric river is pushed upwards, causing much of that water vapor to condense and fall to the ground as rain or snow, creating an atmospheric river-driven storm.
Rivers in the Sky
Atmospheric rivers are the largest “rivers” of fresh water on Earth.
While atmospheric rivers are pretty different from rivers of liquid water down on the ground, they transport enough water to deserve their moniker as rivers. Studies of atmospheric rivers over the Pacific have found that they transport water vapor at a rate equal to 7–15 times the average daily discharge of the Mississippi River. They can be hundreds to thousands of miles long, and though they are narrow in the context of weather systems, "narrow” can mean up to 300 miles across!
Atmospheric rivers are always flowing somewhere on Earth, even though they don’t consistently stay in one place like rivers on the ground. At any given time, 90% of the water vapor moving toward the poles is concentrated in about 4-5 atmospheric rivers across the globe. Together, these narrow bands of flowing water vapor cover less than 10% of the circumference of the planet.
Atmospheric river storms can affect people around the country and the world. Scientists estimate that atmospheric rivers provide over half of the mean annual runoff on the east and west coasts of North America, France, northern Spain and Portugal, the United Kingdom, southeastern South America, southern Chile, Southeast Asia, and New Zealand.
Rivers in the Sky: USGS
There’s a rating system for atmospheric rivers like there is for hurricanes.
Like the scales for hurricanes and other hazards, the rating scale for atmospheric rivers is based both its physical characteristics (wind speed for hurricanes, quantity of water vapor for atmospheric rivers) and on the level of destruction it causes.
While other rating systems are focused solely on the hazards of the event, the atmospheric river system incorporates the idea that these events can be beneficial, hazardous, or both. On the low end of the scale, AR Cat 1 events rated as primarily beneficial and at the high end, AR Cat 5 events primarily hazardous . . .
Rivers in the Sky: USGS
Though an atmospheric river can help extinguish fall fires, they can increase the hazard of past and future wildfires.
When a severe wildfire burns on a hillside, little vegetation remains, and the slope is vulnerable to flash floods and debris flows. Fires can also make the top layer of soil non-absorbent for a short time after the fire, so that water runs right down.
As a result, the rain brought by atmospheric rivers, in combination with more localized weather patterns, can lead to especially hazardous conditions near burn scars.
Before a fire, forests act like a sponge and a water filter, meaning that rainwater can recharge drinking water supplies and only needs minimal treatment before use. After a fire, forests respond to rainfall as if the ground is covered in a layer of plastic wrap. Water cannot penetrate into the soil and huge amounts of surface runoff from rainstorms carry ash, sediment and other pollutants downstream into streams and reservoirs.
Rivers in the Sky: USGS
An atmospheric river mega-storm could be California's other “Big One.”
If you live on the West coast, you’ve likely heard about “the big one” or even “the really big one,” phrases that refer to potential major earthquake events along the faults of California and the Pacific Northwest.
But there’s another “big one” you may not have heard of: according to USGS natural hazards scientists, an atmospheric river-driven mega-storm that could cause catastrophic damage is plausible, if not inevitable, for California. Such a storm could cause extensive flooding across the state, raising environmental health concerns, causing thousands of landslides, disrupting critical infrastructure for days or weeks and causing 350 billion dollars in damages and 290 billion dollars in business interruption losses.
USGS scientists have developed ARkStorm, a hypothetical, scientifically realistic future winter storm scenario, to figure out all the details of what such an event would look like. ARkStorm (for Atmospheric River 1,000) was designed to be similar in intensity to the California winter storms of 1861 and 1862, the largest and longest California storms in the historic record and the cause of the Great Flood of 1862. This type of storm would produce precipitation at levels only experienced on average once every 500 to 1,000 years.
Rivers in the Sky: USGS
Atmospheric rivers are expected to increase in intensity in California due to climate change.
Human-caused climate change is increasing the intensity of many extreme weather events, and atmospheric rivers are no exception, at least in California. Research by USGS scientists and partners has found that over the past 70 years, there is a pattern of increasing water vapor transport onto the West Coast associated with ocean surface warming. Atmospheric rivers aren’t predicted to become more frequent, but California’s precipitation will become more volatile, with more water concentrated into a smaller number of higher-intensity atmospheric river events.
High-intensity atmospheric river storms can cause a lot of damage, and there are likely to be more such storms in our future. But with the help of USGS science, we have the information and tools to prepare for even a “big one.”
Unlike earthquakes or fires, scientists can predict the timing and strength of atmospheric rivers several days in advance, allowing people to stock up on emergency food and water, make preparations for shelter, and avoid high-risk areas.
Over the long term, the studies like the ARkStorm Scenario can help raise awareness of a future big storm and inform major logistical planning and infrastructure development, helping people prepare for major atmospheric river storms and limit their destruction.
"Buried" rivers
This story is part of a special National Geographic News series on global water issues.
Rivers are the lifeblood of many plant, animal, and human communities. Yet many of the world's rivers have been dammed, degraded, polluted, and overdrawn at alarming rates.
Some of the world's great rivers, from the Colorado to the Indus, don't always reach their ends because people have diverted so much water for agriculture, industry, and municipal uses.
Other rivers have been completely covered over by development, as people attempted to "tame" nature by ending flooding and maximizing usable land area.
Underground rivers
Sunswick Creek in the Queens neighborhood of New York City fell prey to expanding concrete in the late 1800s. Appearing on maps in the 1870s, Sunswick Creek was soon completely covered over. Now, it exists only as a meager flow through buried sewer-like pipes, as documented in this photo by Steve Duncan. Duncan notes that the burial process appears to have occurred in multiple phases, based on his explorations of the dank channels.
Underground rivers
Tibbets Brook, New York City, starts just north of the Bronx and then flows into the borough's leafy Van Cortlandt Park, where it fills a small lake. Thanks to historic development, the brook is then forced underground at Tibbett Avenue. It then flows under the Bronx through a large, double-channeled brick sewer until it reaches the Harlem River Ship Canal, which was dug in the 1890s, shaping the border with Manhattan.
Before development, the Lenape Native Americans who lived in the area took advantage of the brook's freshwater and plentiful fish and game, which included muskrats, raccoons, rabbits, skunks, and many species of birds. The Lenape called the stream Mosholu, meaning "smooth or small stones."
Underground rivers
The Neglinnaya River, Moscow, used to flow across Moscow from north to south, until it was buried underground in 4.7 miles of tunnels. Today it drains into the Moskva River via two openings. The Kremlin was built on a hill west of the Neglinnaya River, with a moat filled from its channel. Over time residents grew weary of the river's flooding, so in 1792, the city diverted its course into a new canal, and filled in the original bed. After a devastating fire in 1812, the river became heavily polluted, so engineers covered it over with a vault.
In subsequent decades, additional tunnels were built or expanded.
Underground rivers
The Wein River was driven below Vienna long ago, where it was integrated into the city's sewer system.
Fans of classic movies may recognize this tunnel from the 1949 Orson Welles film The Third Man, set in postwar Vienna.
Underground rivers
River Sheaf, Sheffield, England
This large area is the end of the tunnel that contains the River Sheaf as it travels through the city of Sheffield. The river emerges from time to time as it passes beneath the city, before it merges with the River Don near Blonk Street Bridge.
The River Sheaf historically suffered severe pollution from industrial activities in the area, especially metalworks, although recent efforts have been made to improve water quality.
Ocean News
Annual Blast of Pacific Cold Water Did Not Occur, Alarming Scientists (NY Times Sept. 12, 2025)
The cold water upwell, which is vital to marine life, did not materialize for the first time on record. Researchers are trying to figure out why.
Each year between January and April, a blob of cold water rises from the depths of the Gulf of Panama to the surface, playing an essential role in supporting marine life in the region. But this year, it never arrived. “It came as a surprise,” said Ralf Schiebel, a paleoceanographer at the Max Planck Institute for Chemistry who studies the region. “We’ve never seen something like this before.”
The blob is as much as 10 degrees Celsius colder than the surface water. In Fahrenheit terms, the water would be 18 degrees colder than the surface water. That cold water is also rich in nutrients from decomposing matter that falls to the ocean floor, providing food for local fisheries and wildlife.
Ocean News
Annual Blast of Pacific Cold Water Did Not Occur, Alarming Scientists (NY Times Sept. 12, 2025)
Dr. Schiebel, one of the scientists who recently documented the lack of this yearly upwelling, identified a likely culprit: The lack of strong trade winds, which typically blow across Panama and kick off the dry season in January. When the trade winds reach the Gulf of Panama, they push hot surface water away from the coast, which makes room for cold water to rise from the deep.
Steven Paton, one of the paper’s co-authors, runs a large environmental monitoring program at the Smithsonian Tropical Research Institute. The record he helps maintain shows the upwelling has taken place annually for at least 40 years. With that data and other long term records, “we can very clearly say something very unusual happened that we need to pay attention to.”
Ocean News
Annual Blast of Pacific Cold Water Did Not Occur, Alarming Scientists (NY Times Sept. 12, 2025)
It’s unclear whether a warming planet played a role in the disappearance of the cold blob this year. But the researchers have a few theories about what affected the trade winds.
Trade winds, like the ones that drive the cold upwelling in the Gulf of Panama, typically form when air moves from high pressure to low pressure systems. But this year Panama saw only a quarter of the usual dry season trade winds and when they did emerge, it was only for a short period of time.
The Bermuda-Azores High is a high pressure system that moves around the Atlantic Ocean, affecting seasonal weather patterns across Europe, Africa and the Americas. A separate, low pressure system, known as the Intertropical Convergence Zone, wraps around the Equator and moves south of Panama in winter. This southward movement, in combination with the difference in pressure from these two systems, causes the force that drives Panama’s dry season trade winds.
Ocean News
Annual Blast of Pacific Cold Water Did Not Occur, Alarming Scientists (NY Times Sept. 12, 2025)
La Niña, the cool phase of an oscillating cycle of water temperatures in the Pacific Ocean, may have shifted the position of the low pressure system. Hot ocean surface temperatures may have also affected the strength of the two atmospheric systems. But the impact of these factors is unclear until more research is done, the researchers said.
Andrew Sellers, a marine ecologist at the Smithsonian Tropical Research Institute, said the disappearance of the cold water upwelling could cause “major repercussions throughout the food web.”
Nutrient rich waters are important for Panama’s fishing industry, concentrated on the Pacific side of the isthmus, rather than in the Caribbean. The upwelling also supports large marine life, like dolphins, rays and migrating whales that pass through the region.
The lower temperatures also provide respite for coral reefs, made up of living organisms that can bleach white and die when they get too hot.
Ocean News
Annual Blast of Pacific Cold Water Did Not Occur, Alarming Scientists (NY Times Sept. 12, 2025)
“The climate is warming, that’s putting coral reefs at risk,” said Dr. Aronson. While corals can adapt to changes in temperature, the climate is changing too quickly for them to keep up in the long run, he said. Sea surface temperatures have risen by more than 1 degree Celsius since humans began burning fossil fuels during the Industrial Revolution, breaking records in 2024 and 2023.
It’s too soon to tell if the blob will return in future years. But if it disappears repeatedly, then “it’s cause for grave concern,” Dr. Aronson said.
There are other cold water blobs across the world, including in the Galápagos and off the coast of Costa Rica, each driven by different air and ocean patterns. As the planet warms, Dr. Schiebel said, other atmospheric pressure systems that drive trade winds may diminish, too. “Our fear is now that it would also happen to other upwelling systems,” he said.
Water crisis
The system that moves water around the planet is increasingly "erratic and extreme," new report finds: CNN, Sept. 18, 2025.
The global water cycle has become “increasingly erratic and extreme” with wild swings between droughts and floods, spelling big trouble for economies and societies, according to a report published Thursday by the World Meteorological Organization.
The water cycle refers to the complex system by which water moves around the Earth. It evaporates from the ground — including from lakes and rivers — and rises into the atmosphere, forming large streams of water vapor able to travel long distances, before eventually falling back down to Earth as rain or snow.
Climate change, driven by humans burning fossil fuels, is upending this process.
Water crisis
The system that moves water around the planet is increasingly "erratic and extreme," new report finds: CNN, Sept. 18, 2025.
Nearly two thirds of global river basins did not experience “normal conditions” last year, grappling with either too much or too little water, according to the WMO’s (World Meteorological Organization) State of Global Water Resources report, an annual analysis of global freshwater, including streams, rivers, lakes, reservoirs, groundwater, snow and ice.
Many regions grappled with a dearth of water in 2024, the planet’s hottest year on record. Amazon rivers fell to unprecedented lows, parts of southern Africa endured a drought so extreme governments said they needed to cull hundreds of animals including elephants, and crops shriveled in areas of the United States such as Texas, Oklahoma and Kansas.
Hot temperatures also affected water quality in nearly every one of the world’s 75 main lakes, the report found.
Water crisis
The system that moves water around the planet is increasingly "erratic and extreme," new report finds: CNN, Sept. 18, 2025.
Nearly two thirds of global river basins did not experience “normal conditions” last year, grappling with either too much or too little water, according to the WMO’s State of Global Water Resources report, an annual analysis of global freshwater, including streams, rivers, lakes, reservoirs, groundwater, snow and ice.
Many regions grappled with a dearth of water in 2024, the planet’s hottest year on record. Amazon rivers fell to unprecedented lows, parts of southern Africa endured a drought so extreme governments said they needed to cull hundreds of animals including elephants, and crops shriveled in areas of the United States such as Texas, Oklahoma and Kansas.
Hot temperatures also affected water quality in nearly every one of the world’s 75 main lakes, the report found.
Water crisis
The system that moves water around the planet is increasingly "erratic and extreme," new report finds: CNN, Sept. 18, 2025.
Despite the heat and drought, “we also observed multiple floods, and even more floods than in other years,” said Stefan Uhlenbrook, a lead author of the report and the director of hydrology, water and cryosphere at the WMO.
Europe experienced its most extensive flooding since 2013, Hurricane Helene brought catastrophic floods to parts of the US, killing at least 230 people, and extensive flooding in West and Central Africa led to around 1,500 deaths.
The world’s icy landscapes suffered, too, according to the analysis.
Glaciers saw widespread losses for the third year straight, losing 450 gigatons of ice — equivalent to a block 4.3 miles tall, 4.3 miles wide and 4.3 miles deep, or enough water to fill 180 million Olympic swimming pools. Scandinavia, the Arctic archipelago of Svalbard and north Asia all experienced record glacial melt, the report found.
Glacial melting has huge consequences for sea level rise and flooding risk, and threatens countries that rely on glaciers for power, irrigation and drinking water.
Water crisis
The system that moves water around the planet is increasingly "erratic and extreme," new report finds: CNN, Sept. 18, 2025.
A record-breaking and astonishingly expansive marine heat wave is underway in the Pacific Ocean, stretching about 5,000 miles from the water around Japan to the West Coast of the United States. The abnormally warm “blob” of ocean water, which is getting a significant boost from human-caused global warming, is affecting the weather on land and could have ripple effects on marine life.
The hot ocean waters around Japan contributed to that country’s hottest summer on record, which featured its all-time national maximum temperature record, set on August 5, at 107.2 degrees Fahrenheit.
On the other side of the Pacific, the ocean heat is also yielding higher humidity in northern California at the start of meteorological fall, and if it persists, could enhance rain and mountain snowfall from wintertime atmospheric rivers.
Water crisis
The system that moves water around the planet is increasingly "erratic and extreme," new report finds: CNN, Sept. 18, 2025.
It’s difficult to put numbers on the total economic cost of an increasingly erratic water cycle but single flood events last year caused billions in damages, Uhlenbrook said. Changing availability and access to water resources can also “fuel tensions and conflicts,” he added.
“Water sustains our societies, powers our economies and anchors our ecosystems,” said WMO secretary-general Celeste Saulo in a statement. “And yet the world’s water resources are under growing pressure and — at the same time — more extreme water-related hazards are having an increasing impact on lives and livelihoods.”
Videos
National Geographic: Animals, They're Just Like Us:
Facebook video—underground rivers
IPCC Report on Water
Water crisis
The ‘blob’ is back — except this time it stretches across the entire North Pacific: CNN, Sept. 19, 2025.
A record-breaking and astonishingly expansive marine heat wave is underway in the Pacific Ocean, stretching about 5,000 miles from the water around Japan to the West Coast of the United States. The abnormally warm “blob” of ocean water, which is getting a significant boost from human-caused global warming, is affecting the weather on land and could have ripple effects on marine life.
The hot ocean waters around Japan contributed to that country’s hottest summer on record, which featured its all-time national maximum temperature record, set on August 5, at 107.2 degrees Fahrenheit.
On the other side of the Pacific, the ocean heat is also yielding higher humidity in northern California at the start of meteorological fall, and if it persists, could enhance rain and mountain snowfall from wintertime atmospheric rivers.
Water crisis
The ‘blob’ is back — except this time it stretches across the entire North Pacific: CNN, Sept. 19, 2025.
The sea surface temperature difference from average across the entire North Pacific smashed an all-time record for the month of August, with reliable data stretching back to the late 19th century.
What worries scientists is the repetitive nature of these events. As climate change causes more heat to be stored in the oceans, ocean temperatures are reaching new heights that could lead to more significant impacts from these heat waves like this.
The North Pacific warmed at the fastest rate of any ocean basin on Earth during the past decade, according to Michael McPhaden, a senior scientist at the National Oceanic and Atmospheric Administration.
Water crisis
Tracking sea surface temperature anomalies in the Pacific Ocean
Satellite data shows sea surface temperature anomalies — areas that are cooler or warmer than expected during the same period in the year — by comparing current readings with past climatology.
Source: NOAA
Water crisis
The ‘blob’ is back — except this time it stretches across the entire North Pacific: CNN, Sept. 19, 2025.
And the entire North Pacific Ocean Basin is involved in the current marine heat wave, standing out starkly on weather maps. This event is unique for its intensity and extraordinary geographic reach, and for its potential to eventually alter large-scale weather patterns if it continues.
If the broad ocean basin-wide heat wave persists, it could influence the wintertime storm track associated with the jet stream, said Daniel Swain, a climate scientist at the University of California, Los Angeles.
In parts of the North Pacific, from the Gulf of Alaska south to the coast of California, this heat wave is known as a “blob” of unusually hot water. It is part of a pattern of marine heat waves in this area following a severe heating event in 2013 that lasted until 2016. That heat wave remains the most severe on record.
Water crisis
The ‘blob’ is back — except this time it stretches across the entire North Pacific: CNN, Sept. 19, 2025.
The moniker refers to how the area of warm water looks on maps showing how different sea surface temperatures are from average. This year it may be something of a misnomer, since the marine heat wave is so huge that it spans the Pacific. It also originated in the Western Pacific and gradually extended eastward.
Past Northeast Pacific Ocean blobs led to a historic die-off of seabirds in coastal Alaska, and affected fish species along with sea lions and other creatures that call this region home.
Water crisis
How Climate Change Impacts Water Access—National Geographic
Climate change is already affecting water access for people around the world, causing more severe droughts and floods. Increasing global temperatures are one of the main contributors to this problem. Climate change impacts the water cycle by influencing when, where, and how much precipitation falls. It also leads to more severe weather events over time. Increasing global temperatures cause water to evaporate in larger amounts, which will lead to higher levels of atmospheric water vapor and more frequent, heavy, and intense rains in the coming years.
Climate scientists predict that this shift will lead to more floods since more water will fall than vegetation and soil can absorb. The remaining water, or runoff, drains into nearby waterways, picking up contaminants like fertilizer on the way. Excess runoff eventually travels to larger bodies of water like lakes, estuaries, and the ocean, polluting the water supply and limiting water access for humans and ecosystems.
Water crisis
How Climate Change Impacts Water Access—National Geographic
When fertilizers from farming wash into lakes and the ocean, they promote the rapid growth of algae. These resulting algal blooms clog coasts and waterways with clouds of green, blue-green, red, or brown algae. The blooms block sunlight from reaching underwater life and diminish oxygen levels within the water. Toxins from the blooms can kill off fish and other aquatic animals, make people sick, and even kill humans. These toxins are especially dangerous because they can survive purification processes, making tap water unfit to consume once contaminated.
Algal blooms also impact industries that rely on the water for business, and often cause local waterfronts to shut down during blooms. As the climate warms, harmful algal blooms happen more often and become more severe.
Water crisis
How Climate Change Impacts Water Access—National Geographic
As the ocean warms, freshwater glaciers around Earth begin to melt at an unsustainable rate, which results in rising sea levels. The freshwater from the melted glaciers eventually runs into the ocean. With the rising of sea levels, salt water can more easily contaminate underground freshwater-bearing rocks, called aquifers. A process called desalination removes salt from salt water, but it is a last-resort, energy-intensive, costly process for places where there are persistent droughts and freshwater is lacking. The Middle East, North Africa, and the Caribbean use desalination to produce freshwater out of necessity.
In the Northern Hemisphere—where snow, a freshwater source, typically accumulates—warmer temperatures mean less snowfall, which leaves less water available in local reservoirs after winter. This negatively impacts farmers, who are left without enough water to irrigate their crops in the growing season.
Water crisis
How Climate Change Impacts Water Access—National Geographic
There are many things that everyone can do to lessen the impact of climate change. Some measures include growing your own fruits and vegetables or buying locally grown produce, since produce is often transported to grocery stores from far away by trucks, which add more carbon dioxide to the atmosphere. You could also walk or ride a bike instead of driving a car. On a larger scale, industries that are dependent on fossil fuels need to make the switch to renewable, cleaner energy sources to influence our planet for the better.
UD resources
Climate Change Hub (https://sites.udel.edu/climatechangehub/)
Climate Change, Sustainability, & Resilience Teach In
Friday September 26, 2025; 5:00 to 7:30 pm
Trabant Center, Multipurpose Room C
University of Delaware
17 W Main St, Newark, DE 19716
https://forms.gle/r2tJuJP3no3edtt69
UD also has CEOE—College of Earth, Ocean, and Environment
Orca Grandmothers
Why do orca grandmothers live so long? It's for their grandkids: National Geographic
Female orcas go through menopause, living up to 90 years—a longstanding mystery. Now, a new study suggests there’s a reason why.
The orca is one of only a handful of mammals known to go through menopause. The reason has remained murky, but now, new research suggests why: Grandmothers boost the survival of their grandcalves.
Scientists who analyzed decades of orca populations in the Pacific Northwest found that young orcas with grandmothers were more likely to stay alive than those without. What’s more, a calf’s risk of death rose dramatically for two years following the death of its grandmother. Because orca societies are matriarchal, it’s likely that these older females carry with them crucial knowledge about food resources that can mean life or death for their kin.
“[A killer whale grandmother’s] greater knowledge and their leadership, especially when times are hard, are helping calves,” says senior author Dan Franks, an evolutionary ecologist at the University of York in the U.K.
Orca Grandmothers
Why do orca grandmothers live so long? It's for their grandkids: National Geographic
Ranging from polar regions to the Equator, orcas live in close-knit family groups of up 40 individuals. The predators work together to hunt a variety of prey, from fish to whales, depending on where they live. Generally, both male and female orcas stay in their natal pod throughout their entire lives, although both sexes search for mates from other pods to prevent inbreeding. Orca females stop reproducing around 40 and can live to 90, whereas males tend to live around 50 years.
Although orcas are listed as data deficient by the International Union for Conservation of Nature, populations are in decline—including those in the Pacific Northwest, which are the most studied orcas in the world. A triple whammy of exposure to toxic chemicals known as PCBs; a drop in the populations of their main prey, chinook salmon; and noise pollution from ocean vessels are all contributing factors to their demise.
That’s why this study, published December 9 in the Proceedings of the National Academy of Sciences, is a powerful piece of evidence for conservationists to protect orcas from such threats.
Orca Grandmothers
Why do orca grandmothers live so long? It's for their grandkids: National Geographic
“The death of a post-menopausal grandmother has an outsized impact on her family group,” he says, “which makes this an important conservation tool.”
“It’s really important work,” adds Janet Mann, an animal behaviorist at Georgetown University in Washington, D.C., who was not involved with the study. “We’re just scratching the surface of what these grandmothers are doing.”
Natural selection would seemingly prioritize a female’s ability to have as many surviving offspring as possible, and ceasing to reproduce long before the end of life would interfere with that. Evolutionary biologists have developed several hypotheses that can explain this dilemma. For one, menopause can help prevent grandmothers and mothers from competing for scarce resources to feed their own young. Giving birth at older ages may also be risky, putting not just mother and baby in peril, but also the mother’s existing children.
Orca Grandmothers
Why do orca grandmothers live so long? It's for their grandkids: National Geographic
Then there’s the grandmother hypothesis, popularized by American anthropologist Kristen Hawkes and her work with the Hadza, a modern group of hunter-gatherers in Tanzania, argues that grandmothers boost the survival of their grandchildren by supplementing food and childcare.
The idea is supported by a variety of studies, including a 2004 analysis of pre-industrial Finns and Canadians, which showed that children with grandmothers were much more likely to make it to adulthood.
Grandmas matter. Intrigued by such human research, Franks and colleagues wanted to see if such an effect occurs in orcas. The scientists pored over 40 years of data sets detailing births, deaths, and various events in the lives of two orca populations that live off the coasts of Washington State and British Columbia.
In all, the team analyzed the survival rate of 378 “grandchildren,” and discovered that the risk of death for a calf was greater when their grandmother had stopped reproducing herself, and when the calf was male. Franks says that post-menopausal orcas are likely able to devote more resources to their grandcalves, which made the grandmothers' eventual deaths especially devastating; the male factor is more of a mystery.
Orca Grandmothers
Why do orca grandmothers live so long? It's for their grandkids: National Geographic
The risk was also highest when salmon populations were low or moderate, suggesting grandmothers are most useful in times of scarcity.
We know that they are leading their family group around foraging grounds, especially in times of need, and we know they share their salmon catches with their young relatives,” Franks says. “But we suspect there is more” to discover about how grandmothers keep their families going.
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Yale Climate Connections
Bill McKibben says cheap solar could topple Big Oil’s power
https://yaleclimateconnections.org/2025/09/bill-mckibben-says-cheap-solar-could-topple-big-oils-power/
Bill McKibben is like that old culture of yeast you revive when you want to start a new batch of sourdough. He makes movements rise.
McKibben is a cofounder and senior adviser of climate activist group 350.org, the founder of Third Act – a climate and democracy group led by U.S. residents over the age of 60 – and the principal instigator behind Sun Day, a nationwide community celebration of solar energy on September 21.
His power as an activist stems from his craft as a writer. McKibben still contributes pieces to The New Yorker, the iconic magazine that serialized Rachel Carson’s Silent Spring in 1962 and then launched his own career by serializing The End of Nature in 1989.
Yale Climate Connections
Bill McKibben says cheap solar could topple Big Oil’s power
https://yaleclimateconnections.org/2025/09/bill-mckibben-says-cheap-solar-could-topple-big-oils-power/
That book, his first, can fairly be described as the first work of popular nonfiction about climate change. Since then, McKibben has published more than 20 books, including his 2007 manifesto for a just and sustainable economic system, Deep Economy, and his 2022 look back at his “suburban boyhood,” when he sang in the church choir and led American Revolutions tours of his historic New England town, The Flag, the Cross, and the Station Wagon. Since 2022, McKibben has also written for his Substack site, “The Crucial Years.”
McKibben’s new book, Here Comes the Sun, is a sober yet upbeat look at “a last chance for the climate and a fresh chance for civilization.” In the book, McKibben argues that now that solar is the most affordable form of energy anywhere on the planet, we have an unprecedented opportunity to scale up climate action to the level required for planetary effect. It is an opportunity, a moment, that we all must seize together, starting this Sun Day.
World Meteorological Organization: Report 2024
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Discussion of Is A River Alive?