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Posts Tagged ‘deep sea’

When the Ice Broke Off

Posted in Uncategorized, tagged , , , , , , , , on May 29, 2025| Leave a Comment »

Photo: NASA Worldview, NASA Earth Science Data and Information System.
Satellite imagery showing the iceberg calved from George VI Ice Shelf in the Bellingshausen Sea, Antarctica, on 19 January 2025.

Not much of a recompense for ruining our planet, but it’s true that global warming is giving scientists a chance to study previously unknown places.

At Schmidt Ocean Institute, we learn about some unexpectedly vibrant communities of ancient corals and sponges in Antarctica.

“An international team on board Schmidt Ocean Institute’s R/V Falkor (too) working in the Bellingshausen Sea rapidly pivoted their research plans to study an area that was, until last month, covered by ice. On January 13, 2025, an iceberg the size of Chicago, named A-84, broke away from the George VI Ice Shelf, one of the massive floating glaciers attached to the Antarctic Peninsula ice sheet.  The team reached the newly exposed seafloor on January 25 and became the first to investigate an area that had never before been accessible to humans.

“The expedition was the first detailed, comprehensive, and interdisciplinary study of the geology, physical oceanography, and biology beneath such a large area once covered by a floating ice shelf. The ice that calved was approximately 510 square kilometers (209 square miles), revealing an equivalent area of seafloor.

“ ‘We seized upon the moment, changed our expedition plan, and went for it so we could look at what was happening in the depths below,’ said expedition co-chief scientist Dr. Patricia Esquete of the Centre for Environmental and Marine Studies (CESAM) and the Department of Biology (DBio) at the University of Aveiro, Portugal. ‘We didn’t expect to find such a beautiful, thriving ecosystem. Based on the size of the animals, the communities we observed have been there for decades, maybe even hundreds of years.’

“Using Schmidt Ocean Institute’s remotely operated vehicle, ROV SuBastian, the team observed the deep seafloor for eight days and found flourishing ecosystems at depths as great as 1300 meters. Their observations include large corals and sponges supporting an array of animal life, including icefish, giant sea spiders, and octopus. The discovery offers new insights into how ecosystems function beneath floating sections of the Antarctic ice sheet. …

“The team was surprised by the significant biomass and biodiversity of the ecosystems and suspect they have discovered several new species.

“Deep-sea ecosystems typically rely on nutrients from the surface slowly raining down to the seafloor. However, these Antarctic ecosystems have been covered by 150-meter-thick (almost 500 feet) ice for centuries, completely cut off from surface nutrients. Ocean currents also move nutrients, and the team hypothesizes that currents are a possible mechanism for sustaining life beneath the ice sheet. The precise mechanism fueling these ecosystems is not yet understood.

“The newly exposed Antarctic seafloor also allowed the international team, with scientists from Portugal, the United Kingdom, Chile, Germany, Norway, New Zealand, and the United States, to gather critical data on the past behavior of the larger Antarctic ice sheet. The ice sheet has been shrinking and losing mass over the last few decades due to climate change.

“ ‘The ice loss from the Antarctic Ice Sheet is a major contributor to sea level rise worldwide,’ said expedition co-chief scientist Sasha Montelli of University College London (UCL), United Kingdom, also a 2019 Schmidt Science Fellow. ‘Our work is critical for providing longer-term context of these recent changes, improving our ability to make projections of future change — projections that can inform actionable policies. We will undoubtedly make new discoveries as we continue to analyze this vital data.’

“In addition to collecting biological and geological samples, the science team deployed autonomous underwater vehicles called gliders to study the impacts of glacial meltwater on the physical and chemical properties of the region. Preliminary data suggest high biological productivity and a strong meltwater flow from the George IV ice shelf. …

“ ‘The science team was originally in this remote region to study the seafloor and ecosystem at the interface between ice and sea,’ said Schmidt Ocean Institute Executive Director, Dr. Jyotika Virmani. ‘Being right there when this iceberg calved from the ice shelf presented a rare scientific opportunity. Serendipitous moments are part of the excitement of research at sea – they offer the chance to be the first to witness the untouched beauty of our world.’ ”

More at Schmidt Ocean Institute, here, and at radio show The World, here. No firewalls.

Photo :A large sponge, a cluster of anemones, and other life is seen nearly 230 meters deep at an area of the seabed. Sponges can grow very slowly, and the size of this specimen suggests this community has been active for decades, perhaps even hundreds of years.

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‘Dark’ Oxygen from the Sea

Posted in Uncategorized, tagged , , , , , , , on September 26, 2024| 3 Comments »

Photo: Carolyn Cole/Los Angeles Times via Getty Images.
Metal deposited over millions of years forms these nodules, which can somehow generate oxygen.

Sometimes it seems like scientists have all the fun. In today’s story, certain researchers of the deep ocean thought their instruments were at fault and complained to the manufacturer. Then one day, ironically, an ad from a deep-sea mining company struck a chord in one scientist and led to some creative thinking.

Allison Parshall writes at Scientific American that some rocklike mineral deposits in the deep sea may have more to them than meets the eye.

“The dark seabed of the Pacific Ocean’s Clarion-Clipperton Zone (CCZ) is littered with what look like hunks of charcoal. These unassuming metal deposits, called polymetallic nodules, contain metals such as manganese and cobalt used to produce batteries, marking them as targets for deep-sea mining companies.

“Now researchers have discovered that the valuable nodules do something remarkable: they produce oxygen and do so without sunlight. ‘This is a totally new and unexpected finding,’ says Lisa Levin, an emeritus professor of biological oceanography at the Scripps Institution of Oceanography, who was not involved in the current research.

“According to Boston University microbiologist Jeffrey Marlow, the idea that some of Earth’s oxygen gas may come not from photosynthesizing organisms but from inanimate minerals in total darkness ‘really strongly goes against what we traditionally think of as where oxygen is made and how it’s made.’ Marlow is a co-author of the new study, which was published in Nature Geoscience.

“The story of discovery goes back to 2013, when deep-sea ecologist Andrew Sweetman was facing a frustrating problem. His team had been trying to measure how much oxygen the organisms on the CCZ seafloor consumed. The researchers sent landers down more than 13,000 feet and created enclosed chambers on the seabed to track how oxygen levels in the water fell over time.

“But oxygen levels did not fall. Instead they rose significantly. Thinking the sensors were broken, Sweetman sent the instruments back to the manufacturer. ‘This happened four or five times’ over the course of five years, says Sweetman, who studies sea­floor ecology and biogeochemistry at the Scottish Association for Marine Science. …

“Then, in 2021, he returned to the CCZ on a survey expedition sponsored by the Metals Company, a deep-sea mining firm. Again, his team used landers to make enclosed chambers on the seafloor and monitor oxygen levels. They used a different technique to measure oxygen this time but observed the same strange results: oxygen levels increased dramatically. …

“The researchers initially thought deep-sea microbes were producing the oxygen. That idea once might have seemed far-fetched, but scientists had recently discovered that some microbes can generate ‘dark oxygen‘ in the absence of sunlight.

In laboratory tests that reproduced conditions on the seafloor, Sweetman and his colleagues poisoned seawater with mercury chloride to kill off the microbes. Yet oxygen levels still increased.

“If this dark oxygen didn’t come from a biological process, then it must have come from a geological one, the scientists reasoned. They tested a few possible hypotheses — such as that radioactivity in the nodules was decomposing seawater molecules to make oxygen or that something was pulling oxygen from the nodules’ manganese oxide — but ultimately ruled them out.

“Then, one day in 2022, Sweetman was watching a video about deep-sea mining when he heard the nodules referred to as ‘a battery in a rock.’ That bit of marketing was only a metaphor, but it led him to wonder whether the nodules could somehow be acting as natural geobatteries. If they were electrically charged, they could potentially split seawater into hydrogen and oxygen through a process called seawater electrolysis. (A battery dropped in salt water produces a similar effect.)

“ ‘Amazingly, there was almost a volt [of electric charge] on the surface of these nodules,’ Sweetman says; for comparison, an AA battery carries about 1.5 volts. The nodules may become charged as they grow, as different metals are deposited irregularly over the course of millions of years and a gradient of charge develops between each layer. Seawater electrolysis is currently the researchers’ leading theory for dark oxygen production, and they plan to test it further.”

More at Scientific American, here. No firewall.

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Bronze Age Shipwreck

Posted in Uncategorized, tagged , , , , , on August 6, 2024| 6 Comments »

Photo: Ilan Ben Zion.
IAA archaeologist Jacob Sharvit (left) and Energean environmental lead Karnit Bahartan examine Canaanite storage jars retrieved from the seafloor of the Mediterranean on May 30, 2024. They are from the Bronze Age (which ran about 3300 to 1200 BC, according to Wikipedia). 

Judging from past comments here, we all like archaeology stories, especially those that explore the mysteries of shipwrecks. It must be something about realizing that nothing is ever completely lost.

At Scientific American, Ilan Ben Zion reports on the recent discovery of a Bronze Age shipwreck in the Mediterranean.

“Golden sunlight fell on the two amphorae, still caked in brown ooze, as they breached the Mediterranean’s waves. Their ascent from the seafloor, more than a mile down and 60 miles from land, had taken three hours. It was the first daylight they had seen in at least 3,200 years, and they came from the only Bronze Age shipwreck discovered in deep waters.

“Archaeologists retrieved these Canaanite storage jars, just two from a cargo of dozens located far off northern Israel’s coast in May.

” ‘It’s the only ship from this period that was found in the deep sea,’ one of the final frontiers of archaeology, says Jacob Sharvit, director of marine archaeology at the Israel Antiquities Authority. Only a handful of other Late Bronze Age ships have been discovered — all of them in shallow coastal waters of the Mediterranean Sea, including in the Aegean Sea.

“Sharvit helped spearhead a complex archaeological operation far offshore, along with the Israel Antiquities Authority (IAA) and offshore gas firm Energean to retrieve the jars from the seafloor.

“In the Bronze Age people shipped these storage jars across the Levant starting around 2000 B.C.E., when maritime trade in the Mediterranean exploded.

“ ‘They’re always either pointy or rounded at the bottom,’ so they rock with ship’s motion but don’t tip over and break, says Shelley Wachsmann, a nautical archaeology expert at Texas A&M University, who was not involved in the research.

“These workaday ceramics evolved so consistently over the centuries that they can be reliably dated with an examination of their shape and design. Based on the recently discovered jars’ neck, the pronounced angle of their shoulders and their pointed base, these amphorae are estimated to date to between 1400 and 1200 B.C.E., the IAA said in a recent press release.

“At that time, the ship and its crew sailed a world of prolific international trade, diplomacy and relative stability in the eastern Mediterranean, which was dominated by the Egyptian and Hittite empires. Merchant ships carrying olive oil, wine, ores, timber, precious stones and numerous other goods plied the seas between Greece, Cyprus, Anatolia, the Levant and Egypt.

” ‘This is the time that the Mediterranean is globalized,’ says Eric Cline, a professor of archaeology at George Washington University. ‘You’ve got lots of commerce, lots of diplomacy and lots of interconnections’ between the Egyptian, Hittite, and Assyrian empires and the lands between them, says Cline, whose newly published book, After 1177 B.C.: The Survival of Civilizations, explores the aftermath of the collapse of this Late Bronze Age international order.

In our own era of globalization, this disintegration draws particular interest among scholars looking for clues into how stable civilizations foundered in the past.

“The first signs of the shipwreck surfaced in 2023, during an environmental survey that Energean conducted ahead of its development of a new undersea natural gas field. The survey’s sonar scans were meant to locate and protect deep-sea ecological hotspots from undersea construction, says Karnit Bahartan, Energean’s environmental lead.

“Subsea surveys of the nearby Leviathan gas field conducted in 2016 by Noble Energy (now part of Chevron) reportedly turned up at least nine deep-sea archaeological sites, including a Late Bronze Age shipwreck. But details of the finds were never disclosed, and the sites were never excavated, according to a Haaretz report in 2020.

“ ‘What we were doing is looking for sensitive areas, sensitive habitats, anything that can be worth saving,’ Bahartan recalls.

“Closer examination of the sonar hits revealed that most were modern trash, Bahartan says as she flips through photographs taken by a remotely operated vehicle (ROV). The images show plastic bags, deck chairs, oil drums and a porcelain toilet, seat included. Occasionally, she says, she and her colleagues might find a solitary amphora or ceramic fragments.

“But one sonar blip turned out to be a large assemblage of jars jutting out of the seabed. ‘I didn’t know if it was something dramatic or not. I just sent it to the [Israel] Antiquities Authority,’ Bahartan says.

“Energean offered the IAA a ride onboard the Energean Star, an offshore supply and construction vessel. … Six hours out of Haifa’s port, the Energean Star hovered over the wreck’s coordinates, and a crane lowered a truck-sized, canary-yellow-and-black ROV into the sea. It took an hour to descend to the bottom. Nearing the seabed, operators released the ROV toward the site. …

“Dozens of jars, nearly identical and about half a meter long, clustered in an oblong patch roughly 46 feet long and 19 feet across. … The ROV circumnavigated the wreck, taking a high-resolution video that would be stitched into a photomosaic of the site. Sharvit picked out a couple jars from the fringes that could be extracted with minimal disturbance.

“Sharvit had hoped to find the ancient crew’s personal effects to help nail down the ship’s origin but spotted none. The IAA is running a so-called petrographic analysis of the ceramics to try to pinpoint where they came from; analyses of residue and trace elements could help identify their contents.

“Cline, who was not involved in the IAA mission or its preliminary study, says the proposed date ‘would place the wreck right in the middle of the most interconnected period of the Late Bronze Age in the Aegean and eastern Mediterranean, which is exciting.’ ”

More at Scientific American, here.

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An Octopus Mystery

Posted in Uncategorized, tagged , , , , , on October 5, 2023| 6 Comments »

Photo: MBARI.
Researchers nicknamed the Muusoctopus robustus species the pearl octopus because of the way they look while upside down protecting their eggs. In 2018, a team of scientists found thousands of M. robustus at the base of the Davidson Seamount, about 80 miles southwest of Monterey, California.

Some people may recall Ringo Starr singing “Octopus’s Garden” on “Abbey Road,” but who knew there was really such a thing as an octopus garden? Kasha Patel describes one at the Washington Post.

“About 80 miles from the coast of central California, thousands of octopuses gather on rocks two miles below the surface of the ocean. This location, dubbed ‘octopus garden,’ is the largest known aggregation of these mollusks in the world. … Scientists have been puzzled why so many octopuses plant themselves in these abysmal, colder waters — until now.

“After three years of monitoring the area, researchers found the site is a popular mating and nesting ground for pearl octopuses, where hot springs help embryos develop twice as fast as expected at this depth. The faster development increases a hatchling’s likelihood of survival through the brooding period, according to a study released [in August] in the journal Science Advances. …

“ ‘We’re supposed to be managing these areas and protecting them for future generations, and we didn’t even know that this habitat was down there [and] what kind of impact it was having,’ said Andrew DeVogelaere, research ecologist and study co-author. …

“The discovery of the octopus garden back in 2018 was lucky, said DeVogelaere, who runs the research program for NOAA’s Monterey Bay National Marine Sanctuary. For more than two decades, researchers have been studying an extinct underwater volcano called the Davidson Seamount. The seamount, located southwest of Monterey, Calif., is one of the largest seamounts in the world and known for its beautiful deep sea corals. It is also one of the most well-studied seamounts in the world, so when DeVogelaere wanted to explore it further, others were skeptical he would find anything new.

“ ‘We said, “Don’t waste your time going there,” ‘ said Jim Barry, senior scientist at the Monterey Bay Aquarium Research Institute and lead author of the new study. ‘ “We’ve been all over it.” ‘ …

“Nevertheless, Barry and his colleagues said there is an unexplored area on the foothills of the seamount that could be interesting to investigate. The researchers then sent a ship to study the area.

“DeVogelaere, who was following along on a video feed, said it was at first pretty dull, just a lot of mud. Then suddenly, they spotted a hoard of balls, like opalescent pearls, on the seafloor.

“They had found the ‘octopus garden,’ home to at least 6,000 nesting, Muusoctopus robustus. … The researchers estimate there could be 20,000 in this nursery.

“For three years, the team monitored the population through cameras and dives with remotely operated vehicles, measuring water temperature and oxygen. They found only adult males and female octopus, developing eggs, and hatchlings at the location, indicating the site was used exclusively for mating and nesting.

“They also noticed shimmering water, which was indicative of a thermal spring — something ‘totally new in this area,’ Barry said. He explained the shimmering water appears when warm water (such as from a thermal spring) and cool waters mix. Water temperature from these thermal springs can reach nearly 51 degrees Fahrenheit, while ambient water temperature is around 35 degrees. …

Typically at near-freezing temperatures in the deep ocean, researchers expected pearl octopus eggs at least five years to hatch. These hatched in just two years.

“ ‘As you get into colder waters, whether it’s polar waters or deeper waters, colder water slows down metabolism, slows down metabolic rates, slows down growth and embryonic development rates,’ Barry said. ‘We think that the warm water is providing some sort of reproductive benefit for them.’ …

“The team thinks the octopus garden is just one of many deep sea octopus environments out there. Just five miles away from the garden, researchers found another octopus nursery near thermal springs. In June, another group of researchers discovered a nursery near thermal springs in Costa Rica.

“[Beth Orcutt, vice president for research at the Bigelow Laboratory for Ocean Sciences in Maine] helped lead the Costa Rica expedition. [She] said both of these discoveries show that these small outcrops of rock on the seafloor, which are often passed over for study to focus on larger seamounts, can be incredibly rich and productive sites of life.

“ ‘I don’t think it’s a one-off curiosity,’ DeVogelaere said. ‘Most of the deep sea hasn’t been looked at.’ ”

More at the Post, here. For a version of the story with no firewall, see CNN, here.

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Octopus Nursery in Pacific

Posted in Uncategorized, tagged , , , , on May 23, 2018| 5 Comments »

Photo: Phil Torres, Dr. Geoff Wheat
Seventeen octopods huddled on the Dorado Outcrop, two miles underwater near Costa Rica. Most are in a brooding (in the sense of baby-launching) posture.

Not sure where I picked up this octopus story, maybe from twitter. But who knows? Sometimes I learn facts about sea creatures from the Octonauts-loving grandchildren. (I’m grateful that cartoons these days have educational content. The cartoons I watched as a child were often no more than a bunch of mice running around and squeaking.)

Maddie Stone reports at Earther, “Scientists have made a truly bizarre discovery on an expanse of cooled lava 150 miles west of Costa Rica and nearly two miles underwater. There, they laid eyes on more than a hundred female octopuses, tending to eggs that didn’t seem to be growing in water that seemed too warm for their liking.

“Deep sea octopuses are a rare sight, and it’s even rarer to catch them in the act of brooding. So when Janet Voight, a deep sea biologist at the Field Museum of Natural History, examined footage collected at the Dorado Outcrop during a 2013-14 study of warm hydrothermal fluids seeping out of cracks in the rocks, it was nothing short of shocking to discover an enormous camp of tentacled, seemingly-expectant moms. …

“It’s [puzzling], because deep sea octopuses tend to thrive in near freezing temperatures. Warm water speeds up their metabolism, causing them to use up too much oxygen. And indeed, when lead study author Anne Hartwell examined the octopods’ breathing patterns in hundreds of hours of video footage collected by an ROV and a crewed underwater vehicle, she learned that those in or near hydrothermal fluids were breathing faster, suggesting oxygen stress.

“Moreover, none of the nearly 200 eggs the researchers examined appeared to be developing at all. …

“The researchers go on to speculate that females are drawn to the area because of the lack of sediment, which makes it easier to anchor their eggs, blissfully unaware of their new home’s thermostat problem.

“As the authors explain, hydrothermal fluid discharges can ramp up quickly at any given site, and once a female chooses a place to brood, she’s stuck with it — stressful environment or not. …

“Nicole Morgan, a deep sea biologist at Florida State University who also wasn’t involved, told Earther in a Twitter DM that while the water is warm, it’s ‘not outside known ranges for the octopus genus.’ The oxygen levels are also low but not lethal, she said, suggesting ‘the authors are probably right that this is sub-par brooding habitat.’

“ ‘I think they have captured a snapshot of what evolution looks like in real life — they are brooding in an area that is stressful but available and not immediately lethal,’ Morgan continued. ‘More likely than not this subpopulation will die out because of the high egg fatality, but if some eggs do survive, that could be a start to speciation.’ ”

More here.

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