Saturday, August 19, 2023
Friday, August 18, 2023
For the team aboard the Okeanos Explorer off the coast of Alaska, exploring the mounds and craters of the sea floor along the Aleutian Islands is a chance to surface new knowledge about life in some of the world’s deepest and most remote waters.
The National Oceanic and Atmospheric Administration research vessel is on a five-month mission aboard a reconfigured former Navy vessel run by civilians and members of the NOAA Corps. The ship, with a 48-member crew, is outfitted with technology and tools to peer deep into the ocean to gather data to share with onshore researchers in real time. The hope is that this data will then be used to drive future research.
“It’s so exciting to go down there and see that it’s actually teeming with life,” said expedition coordinator Shannon Hoy. “You would never know that unless we were able to go down there and explore.”
“We’re also going to be looking through the water column to see what interesting animals and fauna that we can see there,” she said.
Kasey Cantwell, the ship’s operations chief, said the data will help researchers and the public better understand these remote stretches of ocean, including marine life and habitats in the area. That could inform management decisions in fisheries. Data could also help detect hazards and improve nautical charts.
“It’s really hard to care for things you don’t understand, to love things you don’t understand,” Cantwell said.
The deep ocean off Alaska’s Aleutian Islands is one of the least mapped places in the U.S., partly due to its remoteness. Modern mapping standards have covered just 34% of the sea floor around Alaska, which has one of the nation’s largest coastal ecosystems, and only a fraction of that has been seen, according to the expedition’s web site.
But the data collection process is laborious.
Thomas Morrow, a physical scientist on the ship, likened the effort to “walking the length of several city blocks in complete darkness with a tiny flashlight.”
Nevertheless, all these small looks add up to a better understanding of what lies in the deepest parts of the sea.
Earlier this year while on an expedition off the coast of Washington state, researchers aboard the ship documented a jellyfish floating in the deep, and soon had a call from an excited scientist who told them the jellyfish was behaving in ways not seen before.
“The feeling of wonder that sometimes happens in that control room is so palpable,” he said.
Thursday, August 17, 2023
With the phasing out of high-sulfur ship fuel, these reflective clouds have become scarcer, leading to ocean warming.
The Atlantic Ocean is running a fever.
Waters off Florida have become a hot tub, bleaching the third-largest barrier reef in the world.
Off the coast of Ireland, extreme heat was implicated in the mass death of seabirds.
For years, the north Atlantic was warming more slowly than other parts of the world.
But now it has caught up, and then some.
Last month, the sea surface there surged to a record 25°C—nearly 1°C warmer than the previous high, set in 2020—and temperatures haven’t even peaked yet.
“This year it’s been crazy,” says Tianle Yuan, an atmospheric physicist at NASA’s Goddard Space Flight Center.
The obvious and primary driver of this trend is society’s emissions of greenhouse gases, which trap heat that the oceans steadily absorb.
Another influence has been recent weather, especially stalled high-pressure systems that suppress cloud formation and allow the oceans to bake in the Sun.
But researchers are now waking up to another factor, one that could be filed under the category of unintended consequences: disappearing clouds known as ship tracks.
Regulations imposed in 2020 by the United Nations’s International Maritime Organization (IMO) have cut ships’ sulfur pollution by more than 80% and improved air quality worldwide.
The reduction has also lessened the effect of sulfate particles in seeding and brightening the distinctive low-lying, reflective clouds that follow in the wake of ships and help cool the planet.
The 2020 IMO rule “is a big natural experiment,” says Duncan Watson-Parris, an atmospheric physicist at the Scripps Institution of Oceanography.
“We’re changing the clouds.”
By dramatically reducing the number of ship tracks, the planet has warmed up faster, several new studies have found.
That trend is magnified in the Atlantic, where maritime traffic is particularly dense.
In the shipping corridors, the increased light represents a 50% boost to the warming effect of human carbon emissions.
It’s as if the world suddenly lost the cooling effect from a fairly large volcanic eruption each year, says Michael Diamond, an atmospheric scientist at Florida State University.
The natural experiment created by the IMO rules is providing a rare opportunity for climate scientists to study a geoengineering scheme in action—although it is one that is working in the wrong direction.
Indeed, one such strategy to slow global warming, called marine cloud brightening, would see ships inject salt particles back into the air, to make clouds more reflective.
In Diamond’s view, the dramatic decline in ship tracks is clear evidence that humanity could cool off the planet significantly by brightening the clouds.
“It suggests pretty strongly that if you wanted to do it on purpose, you could,” he says.
The influence of pollution on clouds remains one of the largest sources of uncertainty in how quickly the world will warm up, says Franziska Glassmeier, an atmospheric scientist at the Delft University of Technology.
Progress on understanding these complex interactions has been slow.
“Clouds are so variable,” Glassmeier says.
Some of the basic science is fairly well understood.
Sulfate or salt particles seed clouds by creating nuclei for vapor to condense into droplets.
The seeds also brighten existing clouds by creating smaller, more numerous droplets.
The changes don’t stop there, says Robert Wood, an atmospheric scientist at the University of Washington.
He notes that smaller droplets are less likely to merge with others, potentially suppressing rainfall.
That would increase the size of clouds and add to their brightening effect.
But modeling also suggests that bigger clouds are more likely to mix with dry air, which would reduce their reflectivity.
Even before the IMO regulations, ship tracks have been a target for researchers to test these ideas.
Given their striking appearance, these linear clouds were a natural candidate for artificial intelligence–based image recognition, Yuan says.
Using such techniques, and 2 decades of calibrated imagery from NASA’s ailing Terra and Aqua satellites, Yuan and co-authors discovered 10 times more ship tracks than previously identified using manual techniques.
In their study, published last year in Science Advances, they also found these tracks decreased by more than 50% in the main shipping corridors after the IMO regulations.
In more recent work, they take this analysis a step further, calculating the amount of cooling associated with the tracks’ brightening effect and the way the pollution extended the lifetime of the clouds.
IMO rules have warmed the planet by 0.1 watts per square meter—double the warming caused by changes to clouds by airplanes, they conclude in a paper under review.
The impact is magnified in regions of heavy shipping, like the north Atlantic, where the disappearing clouds are “shock to the system,” Yuan says.
The increase in light, which was worsened by a lack of reflective Saharan dust over the ocean this year, “can account for most of the warming observed” in the Atlantic this summer, he says.
Instead of focusing on visible tracks, Watson-Parris and his colleagues started with ship location data, combining those coordinates with weather records to project where the ships’ pollution traveled.
They compared clouds at these locations with nearby clouds free of any ship pollution.
In Nature last year, they reported that these “invisible” ship tracks not only enhanced low lying marine clouds, as usual, but also markedly increased the volume of puffy cumulus clouds higher in the atmosphere, previously thought to be immune to the influence of ship pollution.
They concluded that air pollution could be causing clouds to cool the climate at roughly double the previously projected strength.
However, when the team then looked at the effect of the IMO rules on these invisible tracks, they received a shock: The decline in pollution didn’t make the cumulus clouds any less puffy, they report in a new preprint in Atmospheric Chemistry and Physics (ACP).
It suggests these clouds have a saturation point, after which added pollution does little to increase their depth, Watson-Parris says.
“We removed 80% of the aerosols, but that’s still not taking us close to the preindustrial state.”
A third way to explore the impact of ship pollution on clouds is not to study them in aggregate, but rather to zoom in on ocean stretches where winds flow in parallel with shipping lanes, keeping the pollution tightly corralled.
Such a stretch exists in the southeast Atlantic, off the coast of Angola.
Observing this region with the Terra satellite, Diamond found that, with lower pollution, the cloud droplet sizes had grown to the largest size, by far, in the past 2 decades.
Extrapolating from there, Diamond estimates in a paper last week in ACP that the IMO rules have caused warming globally at levels like those seen by Yuan.
Later this year, Diamond, Yuan, and others will begin to compare their techniques for studying the interaction of pollution and clouds, under the auspices of the National Oceanic and Atmospheric Administration’s small geoengineering research program.
After a few more years, Wood says, “We’re really going to have something to say about these cloud adjustments.”
- BBC : How Do You Know a Cargo Ship Is Polluting? It Makes Clouds
- GeoGraage blog : Ship tracks show how aerosols affect clouds fast and slow / NASA study finds evidence that fuel regulation reduced air ... / Image of the week : signs of ships in the clouds / Pollution playing a major role in sea temperatures / Ship exhaust makes oceanic thunderstorms more intense / Image of the week : satellite's view of ship pollution / Sulphur-emissions rules for shipping will worsen global ... / Sentinel tracks ships' dirty emissions from orbit / Sentinel-3 and the ocean carbon conundrum
Wednesday, August 16, 2023
From Wired by Matt Simon
During the Cold War, the US built a network of tunnels in the Greenland ice sheet.
Sixty years later, the base has provided a critical clue about the climate crisis.
IN 1959, THE United States began construction of a real-life version of the frozen Echo Base from The Empire Strikes Back.
The plan for Camp Century was to test snow tunneling technologies in northwest Greenland, not far from the north pole, ostensibly for scientific research.
Really, the US was flexing its military muscle, and may have been considering Project Iceworm, a way to hide 600 nuclear missiles in thousands of miles of snow tunnels across northern Greenland, close to the former Soviet Union.
The island’s massive ice sheet had other ideas for Camp Century, though—ice shifts and flows, making this not a particularly ideal place to stash nukes or run the nuclear reactor that powered the base.
But before everyone fled, researchers did manage to dig up some actual scientific dirt, drilling a 4,550-foot-deep core into the ice sheet.
When they hit earth, they drilled a further 12 feet, bringing up a plug of frozen sand, dirty ice, cobbles, and mud.
The military moved that ice core from its own freezers to the University at Buffalo in the 1970s.
The core ended up in Denmark in the '90s, where it was kept frozen, so that now it provides scientists with invaluable insight into ice ages past.
Now, an international team of researchers has analyzed that sediment, and made a major scientific discovery.
“In that frozen sediment are leaf fossils and little bits of bugs and twigs and mosses that tell us in the past there was a tundra ecosystem living where today there's almost a mile of ice,” says University of Vermont geoscientist Paul Bierman, coauthor of a new paper describing the finding in the journal Science.
“The ice sheet is fragile. It can disappear, and it has disappeared. Now we have a date for that.”
Photograph: Halley Mastro/University Of Vermont
Previously, scientists reckoned that Greenland iced over some 2.5 million years ago, and has been that way since.
In 2021, Bierman and his colleagues determined that it was actually ice-free sometime in the past million years.
Now, they’ve dated the tundra ecosystem captured in the Camp Century core to a mere 416,000 years ago—so northwestern Greenland couldn’t have been locked in ice then.
Scientists also know that at that time, global temperatures were similar or slightly warmer than what they are today.
However, back then, atmospheric concentrations of planet-warming carbon dioxide were about 280 parts per million, compared to today’s 422 parts per million—a number that continues to skyrocket.
Because humans have so dramatically and rapidly warmed the climate, we’re exceeding the conditions that had previously led to the wide-scale melting of Greenland’s ice sheet and gave rise to the tundra ecosystem.
“It's a forewarning,” says Utah State University geoscientist Tammy Rittenour, a coauthor of the new paper.
“This can happen under much lower CO2conditions than our current state.”
That melting could be incredibly perilous.
The new study finds that the Greenland ice melt 400,000 years ago caused at least 5 feet of sea level rise, but perhaps as much as 20 feet.
“These findings raise additional concern that we could be coming perilously close to the threshold for collapse of the Greenland ice sheet and massive additional sea level rise of a meter or more,” says University of Pennsylvania climate scientist Michael Mann, who wasn’t involved in the research.
Today, less than a foot of global sea level rise is already causing serious flooding and storm surge problems for coastal cities—and that’s without the potential for an additional 20 feet.
If Greenland melts again, it could reach a point of no return, relentlessly driving up sea levels as it does so.
When an ice sheet melts, it exposes darker dirt beneath it, which absorbs more of the sun’s energy, raising local temperatures and driving more melting.
“If too much mass is lost and the elevation of the surface drops significantly, the resulting warming of the surface makes regrowth of the ice sheet more difficult,” says Pennsylvania State University geoscientist Richard B.
Alley, who wasn’t involved in the research.
“The new paper provides further evidence that even moderate sustained warmth will drive major melting in Greenland, forcing sea-level rise.”
Exactly how the Greenland ice sheet might degrade in the future is still unclear, and requires more research.
Temperatures 400,000 years ago were similar to what they are today, but the natural warming that drove Greenland's melting back then happened gradually.
Humans have quickly and dramatically warmed the planet since preindustrial times, and anthropogenic CO2 will stay in the atmosphere for thousands of years, unless people invent a way to remove it at large scale.
We can also reducetemperatures.
If we slash emissions, Mann says, Greenland’s ice sheet might remain stable.
So, how did this research team figure out that northwest Greenland was an ice-sheet-free tundra 400,000 years ago? The sediment from the Camp Century core was loaded with organic material, but it was way too old to examine by using carbon dating, which is only effective for periods up to 50,000 years back.
“We pulled out little twigs and leaves, and we immediately sent them off radiocarbon dating, and they came back what we call ‘radiocarbon dead,’” says Rittenour.
“There were no traces of radioactive carbon left in the sample.”
So instead, Rittenour used light—specifically the luminescence of bits of feldspar buried in the sediment.
Free electrons build up in the minerals over time, producing a "luminescence signal." Exposure to sunlight essentially neutralizes this signal, but once these minerals became buried under thousands of feet of ice, the sun’s rays could no longer reach them, and the electron buildup recommenced.
In a darkroom in the lab, Rittenour could peer into the Camp Century samples using infrared light.
“We can use light of one wavelength, and we measure the luminescence coming off at a different wavelength,” says Rittenour.
“The older the sample, the more luminescence it produces.” That allowed them to determine how long it had been since the feldspar in the sediment last saw sunlight.
To complement this, at the University of Vermont, Bierman looked at the mineral quartz in the samples for rare isotopes of beryllium and aluminum.
“They're formed when cosmic rays, these really high energy particles, come zipping into Earth from beyond the solar system.
And occasionally, they'll smack an element in the quartz grain,” says Bierman.
“By looking at the ratio of those two isotopes, we can tell how long something's been buried away from those cosmic rays.” The result told them that this material had sat out on the landscape for less than 16,000 years.
Scientists are now racing to drill more ice cores in Greenland to gather more soil.
Although the Camp Century core gives them the basis for modeling that they can use for estimations, with more cores, they can better work out how much of the island’s ice had disappeared and how quickly—and what that might presage about the ice sheet’s modern decline.
“We now have definitive evidence that when the climate gets warm, the Greenland ice sheet disappears,” says Bierman.
“And we've just started warming the climate.”
“We use the past to try to understand the future and understand the present,” Bierman continues.
“And that makes the future a little frightening.
Not that we should run from it—but to me, it's a call for action.”
- USU : Greenland Has Greener History Than We Thought, Says USU Geoscientist
- UB : Ancient soil once stored at UB shows Greenland melted recently … and could melt again
- Hiistory : When the Pentagon Dug Secret Cold War Ice Tunnels to Hide Nukes
- Atlas Obscura : Camp Century (Project Iceworm)
- PopScience : How a top-secret nuclear project became a gold mine for data on Greenland’s ice sheet
- Vice : A Top-Secret US Military Base Will Melt Out of the Greenland Ice Sheet
- Insider : A bunch of toxic waste from the army's 'Project Iceworm' is going to leak into the Arctic
Tuesday, August 15, 2023
From Hakai Mag by Dag Goering
Out in the Atlantic Ocean, roughly 100 kilometers off the northwest coast of Africa, lies an archipelago known as the Canary Islands, created millions of years ago by intense volcanic activity.
The biggest and most populated island, Tenerife, rises from the deep-ocean floor to a series of peaks, one of which is the third-largest volcano in the world.
Tenerife’s interior highlands are a moonscape, while its coastline of lava rock and sheer cliffs is pounded by surf.
In contrast to most of the island’s stark geology, north of the island’s capital, Santa Cruz, is a long crescent-shaped beach of soft yellow sand, with groves of palm trees and a calm bay created by a long breakwater.
This is Playa de las Teresitas, a magnet for northern European tourists craving winter sun.
But most of the people sunbathing on Teresitas are likely unaware of what lurks in the shallow waters lapping the shoreline.
The bay—engineered and less than 10 kilometers (6 miles) from the Canaries’ second-largest city—is a surprising haven for pups of one of the world’s most critically endangered fish: the angelshark.
When the Spanish took control of the Canaries in the 1400s, they began cultivating cash crops: cochineal and sugar cane in the beginning, and later adding bananas, tomatoes, and other valuable commodities.
For centuries, the islands’ economy thrived, but it was a fragile wealth.
Over the years, livelihoods were threatened by cycles of crop disease, competition from cheaper markets, and lava flows that wiped out harvests and turned good agricultural land into barren terrain.
In the 1950s, the boom in package tourism showed promise as a new cash crop.
But while the islands had the sunshine, warm climate, and ease of access from Europe needed for this new industry, they were missing a vital element: picture-postcard sandy beaches.
Cue planners on Tenerife, who concocted an audacious plan to make over one of the island’s exposed lava-rock beaches.
They chose a stretch of coastline close to Santa Cruz and expropriated the avocado farms and other smallholdings.
Earthmovers leveled the foreshore and intertidal zone, and they constructed a breakwater over a kilometer long.
And then, from the Western Sahara on Africa’s northwest coast, they shipped in the pièce de résistance: 240,000 tonnes (264,555 tons) of sand.
As anticipated, tourists arrived.
Unanticipated was what their presence gave to one of the world’s most endangered fish species—visibility.
Maybe angelsharks always gathered here, but until recently, no one really knew.
Along Playa de las Teresitas, rows and rows of tourists lounge on beach chairs under umbrellas or pad across soft sand to cool down in the water.
The breeze creates tiny sapphire-tipped waves on the water’s surface, a magical cover for what lies beneath: an angelshark nursery.
Female angelsharks regularly migrate to these ideally sheltered waters to give birth to anywhere between eight and 25 live pups, which remain in the shallows for about a year.
Feeding on cuttlefish and other small prey, they grow to around 50 centimeters (20 inches), about the same length as a newborn baby.
Then they disappear for years until they are mature.
Where they go is a mystery.
The ancient Greeks fished them; Pliny the Elder described the use of their skin to polish wood and ivory.
On the British Isles, they were called monkfish for their resemblance to a monk’s hooded robes.
With the advent of industrial bottom trawling in the late 1800s, they were easily caught and became a common food fish.
By the 1960s, aggressive fishing of angelsharks, coupled with their extremely low reproductive rate, led to a dramatic decline in their populations.
Targeting them eventually became commercially unviable and the name monkfish was relegated to another species, the anglerfish.
But angelsharks were still by-catch in other fisheries, and by the early 1970s, as developers barged Saharan sand to Tenerife, the fish were pushed close to extinction in most parts of the North Atlantic and the Mediterranean.
photo : Mike Sealey
In the European Union and the United Kingdom, it has become illegal to fish or retain angelsharks.
If one is accidentally caught, fishers must return it alive to the sea.
But the main threat to angelsharks remains the powerful bottom-trawling industry, which accounts for over 30 percent of fish landed in the European Union.
The story in the Canary Islands is slightly different.
Michael Sealey, a marine biologist with the Angel Shark Project (ASP) in Tenerife, says that bottom trawling has never been as viable in the Canaries as in most of Europe and the Mediterranean.
The seabed is mostly too deep, he explains, the underwater topography laced with jagged seamounts and reefs where fishing gear can get hung up.
On top of that, the European Commission has halted all trawling in the Canaries since 2005.
But biologists only became aware about a decade ago that the Canaries host an angelshark population.
Subsequently, in 2014, the Universidad de Las Palmas de Gran Canaria, Museum Koenig Bonn, and Zoological Society of London collaborated to establish ASP.
The project’s goal: to gather data on critical habitats, movement patterns, and reproductive biology of angelsharks, and work with local communities and officials to protect the fish.
Life history information is crucial for developing effective conservation strategies and protecting valuable, if improbable, habitat—like Playa de las Teresitas.
But angelsharks are not the easiest of research subjects.
They are masters of disguise, so spotting them is a challenge.
They have a peculiar flattened shape and spend most of their time lying on the ocean bottom partially covered by sand.
Their coloring—reddish- or greenish-brown scattered with small white spots—helps them blend into the seabed.
Help has come in the form of citizen science: everywhere in the Canary Islands, recreational divers and fishers are invited to make online reports of any sightings or accidental catches of angelsharks.
Through an ASP initiative, dive operators conduct friendly competitions to see which company can record the most sightings, thereby increasing data collection, particularly from citizen scientists.
He helps with procedures such as tagging the fish with either spaghetti tags—an easily attached plastic loop—or acoustic tags.
Both are done on the spot without having to catch the fish or lift it out of the water.
“We work in a team and practice beforehand,” Martinez says.
After an angelshark has been spotted in the sand, the team places a mesh attached to a sturdy frame over the animal.
They take a small sample of fin for DNA analysis and attach a tag to the base of the dorsal fin.
The whole procedure, when done properly, takes less than a minute.
Surveys have shown that other beaches in the Canary Islands are also potential nursery sites.
Interestingly, most of them have been altered, like Teresitas, to make them more attractive to people.
On Lanzarote, Playa Chica boasts another long sweep of imported sand.
It’s a magnet for divers—as well as a spectacular and easily accessible site—so the number of sightings of mature angelsharks off this shoreline is one of highest in the whole archipelago.
How do the sharks react to these shoals of wetsuited humans? Alba Esteban Pacheco, a biologist and former dive instructor with Euro Divers Lanzarote, admits that while there have been instances of divers getting too close to the sharks, most dive companies are sensitive in this regard and brief their clients well.
They have little choice: In 2019, Spain introduced legislation in the Canaries that made disturbing the sharks or harming their habitat and breeding grounds a criminal act subject to large fines.
Pacheco is very clear that she keeps her dive clients at least the recommended one meter (3.3 feet) distance from any angelsharks they find hiding in the sand.
“Also,” she says, “these days, with everyone videoing everything and posting it on social media, it’s hard for divers to step out of line.”
But is this enough?
But she adds that much more needs to be done to ensure the long-term survival of angelsharks in areas like Playa Chica.
A recovery plan ASP developed with local authorities is in the final stages.
It will include measures such as signage along sensitive coastlines and establishing a code of conduct for divers throughout the Canaries.
Among international dive communities, the word is out about the chance to see mature angelsharks in the Canaries, and this is a growing part of the tourism sector.
Indeed, shark diving all over the world is a boon to economies.
It generates over $24 million yearly in the Canaries.
Globally, shark-diving tourism generates over $300 million yearly, and local communities benefit much more from shark diving than from shark fishing.
In some cases, this has led to the creation of marine reserves, such as in Fiji, which help other marine species as well.
Many divers may now be cognizant of the fragility of the angelshark population, but what about all those people splashing about and swimming in the all-important nursery areas just off the beaches? Sealey thinks that human activity in the shallow nursery areas influences angelshark behavior.
On busy beaches like Teresitas, juveniles normally retreat to deeper water during the day when lots of people are around.
During the COVID-19 pandemic, restrictions kept people off the beach.
After almost two years of peace, angelsharks seemed unprepared for the people wading back into the water, as swimmers reported an unusual number of bites soon after restrictions lifted.
The fish rely on their camouflage for protection, but when stepped on, they might lunge up from their hiding place and bite, though they usually swim away.
Known locally as “gummings,” the bites are not serious and rarely draw blood.
But the increase in gummings was an indication that the juveniles had adapted to remaining hidden in the shallows 24/7 to conserve energy.
Post-pandemic, angelsharks have adapted again, by heading into deeper water earlier in the day and avoiding interactions with humans, as do many other urban wildlife species.
Back in the 1970s, did angelsharks also adapt to the Canaries’ headlong efforts to redesign itself for tourists? It’s intriguing to think that the massive, environmentally disruptive projects to remake beaches could have accidentally enhanced the habitat for one of the world’s rare fish species.
But what’s clear is that after the breakwater was built and the sand arrived, people followed, and in the calm, shallow waters they began to see baby angelsharks.
And unlike how many an association between humans and wildlife ends—in conflict and dead animals—this time it led to conservation.
Monday, August 14, 2023
From Scientific American by AshelyBalzer Vigil
Elated researchers watched baby octopuses hatch en masse near Pacific Ocean hydrothermal vents
The tiny baby octopuses—each about the size of a nickel—emerged from soft, membranous eggs, clutched in their mothers’ protective embrace.
One by one the hatchlings gracefully unfurled their delicate tentacles and floated away into the abyss.
This awe-inspiring scene unfolded as stunned scientists watched, via an underwater camera, from a ship on the ocean’s surface during a recent expedition.
Though brooding deep-sea octopuses had previously been spotted in this area near hydrothermal vents on the Pacific Ocean seafloor off Costa Rica, researchers had thought the spot would be much too warm for the cephalopods to actually produce viable offspring.
“The mission control room erupted in squeals of amazement––people pointing their fingers at the screens excitedly, clapping, hugging––when we witnessed live baby octopuses on the seafloor,” says expedition co-leader Beth Orcutt, vice president for research at the Bigelow Laboratory for Ocean Sciences, a nonprofit research institute.
They had only been looking to confirm that hydrothermal fluids were seeping out of the vents, and they were surprised to find the warm water populated by an unknown species of octopus of the genus Muusoctopus incubating eggs.
This behavior seemed strange because the octopuses were found in an area that is nearly 20 degrees Fahrenheit warmer than the surrounding waters.
That may not sound like much because humans are regularly exposed to wide temperature swings, but deep-sea octopuses spend nearly their entire life in chilly waters that vary little in temperature.
The team thought it was surely too hot near the vents to yield viable young, and indeed, they saw no embryos within the eggs.
But when scientists returned last month onboard the nonprofit Schmidt Ocean Institute’s research vessel Falkor (too), they not only saw promising embryos but witnessed baby octopuses actually emerging from eggs.
Watching through cameras on a remotely operated underwater vehicle, the team witnessed the brooding grounds transform into an active and thriving octopus nursery in real time.
The spectacle has opened up a whole new realm of questions.
“The warm fluids seeping out of Earth’s crust here could speed up the gestational process,” Orcutt says.
“And it may just be this species that has adapted to withstand the heat while brooding to gain that advantage.”
It also hosts strange creatures, such as glass sponges and isopods—translucent, alien-looking animals that have inhabited Earth for hundreds of millions of years.
Credit: Schmidt Ocean Institute (CC BY-NC-SA)
The team has already identified another deep-sea octopus nursery on a nearby outcrop, which is only the third one to be found anywhere in the world.
(There is also a deep-sea octopus nursery at the Davidson Seamount, about 80 miles off the coast of central California.)
Investigating such an unexplored area is likely to turn up additional surprises.
“Our focus is the octopus, but we’ve been collecting other specimens for specialists in other groups to study, too,” says the expedition’s other co-leader, Jorge Cortés-Núñez, a professor emeritus of biology at the University of Costa Rica.
No one yet knows how long it takes for these octopus eggs to hatch, but it is likely several years.
That’s a long time, considering how vulnerable the mothers and eggs are while brooding.
“We’re eager to find out how common these octopus nurseries are, partly to see whether there should be special protections in place at the Dorado Outcrop,” Cortés-Núñez says.Scientists and lawyers in Costa Rica plan to propose designating the Dorado Outcrop, along with various other deep regions, as marine protected areas; this would help preserve them and maintain the benefits they offer to the surrounding ecosystem, such as providing a habitat for deep-sea species.
But even if the area were shielded from direct human threats, its inhabitants could still be harmed by climate change.
Warming ocean waters and reduced oxygen levels could put too much strain on deep-sea organisms, which usually spend nearly all of their lives in frigid, unchanging conditions.
“If even a few organisms are unable to thrive in alternate conditions, there could be wide-reaching consequences to ecosystem dynamics,” says Anne Hartwell, a Ph.D.
candidate at the University of New Hampshire, who was not involved in the expedition but wrote a 2018 paper about the brooding octopuses at the Dorado Outcrop.
Hartwell says this exciting discovery of successful octopus reproduction underscores how much more remains to be uncovered about the ocean and its inhabitants.
“There is a sea of knowledge to be learned about deep-sea biodiversity and ecology,” she adds.
- Schmidt Ocean : Returning to the Dorado Outcrop
Sunday, August 13, 2023
Located halfway between Australia and Antarctica, Macquarie Island is an important stopping place for people and penguins.
The remote island has been used by explorers on their way to map uncharted reaches of Antarctica.
And the island is far enough south to be suitable habitat for sub-Antarctic species, such as seals and penguins.
Waves and westerly winds from the Southern Ocean have sculpted the island’s shoreline, forming several bays and beaches.
The bays and beaches provide habitat for seal and penguin colonies.
Penguins and seals were hunted for their blubber until 1933, when the island was declared a wildlife sanctuary.
The island’s notable biodiversity and geological features contributed to it being listed as a UNESCO World Heritage site in 1997.
- ABC News (2022, October 29) Penguin populations in new fight for survival on Macquarie Island.
- Australian Government World Heritage Places — Macquarie Island.
- Australian Marine Parks Macquarie Island Marine Park.
- Pascoe, P. et al. (2022) The current trajectory of king penguin (Aptenodytes patagonicus) chick numbers on Macquarie Island in relation to environmental conditions.
ICES Journal of Marine Science, Volume 79, Issue 7, September 2022, Pages 2084–2092.
- Smithsonian Magazine (2012, January 27) The Most Terrible Polar Exploration Ever: Douglas Mawson’s Antarctic Journey.
- Tasmania Parks and Wildlife Service Macquarie Island World Heritage Area.
- United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Convention Macquarie Island.
- Wienecke, B., and Robertson, G.(2002) Foraging Areas of King Penguins from Macquarie Island in Relation to a Marine Protected Area.
Environmental Management 29, 662–672.