Ocean Conservation & Tidalpunk

Something is pumping out large amounts of oxygen at the bottom of the Pacific Ocean, at depths where a total lack of sunlight makes photosynthesis impossible.

The phenomenon was discovered in a region strewn with ancient, plum-sized formations called polymetallic nodules, which could play a part in the oxygen production by catalysing the splitting of water molecules, researchers suspect.

“We have another source of oxygen on the planet, other than photosynthesis,” says study co-author Andrew Sweetman, a sea-floor ecologist at the Scottish Association for Marine Science in Oban, UK — although the mechanism behind this oxygen production remains a mystery. The findings could also have implications for understanding how life began, he says, as well as for the possible impact of deep-sea mining in the region.

Sweetman and his collaborators first noticed something amiss during field work in 2013. The researchers were studying sea-floor ecosystems in the Clarion–Clipperton Zone, an area between Hawaii and Mexico that is larger than India and a potential target for the mining of metal-rich nodules.

“I suddenly realized that for eight years I’d been ignoring this potentially amazing new process, 4,000 metres down on the ocean floor,” says Sweetman.

Ocean diatoms, like Cylindrotheca closterium, build biomass by both photosynthesis and consuming organic carbon, a finding that may change our view of the global carbon cycle.

This research is led by bioengineers, bioinformatics experts, and other genomics researchers at the University of California San Diego. The new findings are published in Science Advances on July 17, 2024.

The team showed that the diatom Cylindrotheca closterium, which is found in oceans around the world, regularly performs a simultaneous mix of both photosynthesis and direct eating of carbon from organic sources such as plankton. In more than 70% of the water samples the researchers analyzed from oceans around the world, the researchers found signs of simultaneous photosynthesis and direct organic carbon consumption from Cylindrotheca closterium.

The research team hopes this work will stimulate interest in taking a much closer look at our understanding of the global carbon cycle, taking into consideration this new broader understanding of how ocean diatoms get their carbon.

What the bacteria feeding the diatoms may be getting out of the relationship is another question for further research.

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2004 ... researchers knew relatively little about the state of the Atlantic meridional overturning circulation (AMOC), an ocean system that transports warm water and nutrients around the Atlantic Ocean.

A new study by René van Westen at Utrecht University in the Netherlands and his colleagues suggests the AMOC could tip towards collapse between 2037 and 2064, with a mean estimate of 2050.

The collapse of the AMOC could lead to rapid sea level rise in North America, a sudden and severe drop in temperatures across northern Europe and serious disruption to monsoons across Asia.

Van Westen and his team’s work is the second study in as many years to predict a mid-century collapse of the AMOC, following a 2023 paper by Peter and Susanne Ditlevsen, both at the University of Copenhagen.

The Intergovernmental Panel on Climate Change (IPCC) says a full AMOC collapse is unlikely in the current century, based on climate modelling.

Niklas Boers at the Potsdam Institute for Climate Impact Research in Germany says other evidence does show that the AMOC has become increasingly unstable in the past century. ... “These uncertainties absolutely prevent you from making sharp estimates of when the actual time of tipping would be,” he says.

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India will apply for licences to explore for deep-sea minerals in the Pacific Ocean

The UN-backed International Seabed Authority (ISA) has issued 31 deep-sea exploration licences, including two for India in the Indian Ocean, but is yet to allow mining because the 36-member body is still working on regulations.

China, Russia, and some Pacific Island nations have already secured exploration licences for the Pacific Ocean.

Opponents of deep-sea mining say that not enough is known about its impact on marine ecosystems.

Some 27 countries have called for a moratorium or suspension of all ocean mining-related activities,

The permits last for 15 years, according to the ISA website.

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The plastic-digesting capabilities of the fungus Parengyodontium album could be harnessed to degrade polyethylene, the most abundant type of plastic in the ocean

A fungus found on litter floating in the North Pacific Ocean can break down the most abundant type of plastic that ends up in the sea.

Vaksmaa believes that the fungus, known as Parengyodontium album, has great potential, but she is cautious about putting it to use in the wild. “If we take a microbe and add it to a natural system, then we may ruin it while trying to do good,” she says. Instead, she suggests it may be best to gather the plastic first and bring it back to land to be digested by P. album that has been grown in bulk. This could be achieved using well-established techniques, similar to those used in the brewing industry, she says.

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Oceans swallow huge amounts of carbon dioxide pollution each year, helping to mitigate climate change, but at the cost of the seas becoming more and more acidic. But what if we could increase the Atlantic’s appetite for the greenhouse gas by giving it the equivalent of a giant antacid tablet?

That is the basic hypothesis behind a controversial geoengineering experiment planned by scientists at the highly respected Woods Hole Oceanographic Institution, a private marine research non-profit organization.

“We don’t want there to be a prospect of a whale or something coming into contact with that,” said Daniel McCorkle, a co-principal investigator for the sodium hydroxide experiment and emeritus scientist in WHOI’s department of geology and geophysics.

“We don’t know exactly what the risks are, because no one has been crazy enough to do this before,” said Ben Day, a Massachusetts-based senior campaign manager for Friends of the Earth. “It’s kind of like the thinking that got us here in the first place: Thinking that we can control Earth’s systems without unintended consequences.”

Even a relatively small amount of sodium hydroxide solution released in the ocean will kill “foundational” marine life, including phytoplankton, zooplankton, and fish larvae, and displace or injure other creatures due to the huge spikes in alkalinity, said James Kerry, an adjunct marine scientist at the James Cook University in Australia.

“I see it, essentially, as trying to address one form of marine pollution — carbon dioxide — with another” pollutant, said Kerry, who is also a senior marine and climate scientist for OceanCare, a marine conservation nonprofit organization based in Switzerland.

Summary:

New research could lead to major improvements in marine oil spill cleanup processes. The innovative study assessed the impact of the Deepwater Horizon oil spill on microscopic seawater bacteria that perform a significant role in ecosystem functioning.

University of Stirling - January 22, 2024

Oxygen is a vital element for virtually all animals on Earth and many microbes. But oxygen concentrations are falling in some of the most valuable ecosystems on the planet. According to a recent paper, the number of freshwater and coastal water bodies with little to no oxygen has increased in coastal areas, with hundreds of regions affected worldwide. Meanwhile, in the open ocean, oxygen-deficient waters have increased fourfold since 1960.

In the new paper, published in Nature Ecology & Evolution, researchers around the globe are urging leaders to acknowledge the ocean’s oxygen loss as a new “planetary boundary.” Planetary boundaries are global thresholds for major Earth systems, beyond which humanity cannot safely operate. The nine existing boundaries include climate change and freshwater. In this Q&A, we spoke with co-author Denise Breitburg, a scientist emerita at the Smithsonian Environmental Research Center, on why ocean oxygen should become the 10th planetary boundary. Edited for brevity and clarity.

James Lange remembers the day he and a team of botanists and conservationists gathered at a rock formation encircled by a thicket of mangroves in Key Largo, Florida. They’d come to the nation’s last wild stand of a rare cacti to confront the inevitable. With sea level rise bringing the Atlantic Ocean ever closer to the withering plants, the group had made the difficult decision to remove the cacti’s remaining green material, preserve it in nurseries, and hope that it might one day be reintroduced in the wild.

Three years later, research published last week reveals what Lange and the others long suspected: The demise of the Key Largo tree cactus is the first recorded case of sea level rise driving a local species to extinction in the United States. Its collapse was a blow to Lange, a research botanist at Fairchild Tropical Botanic Garden in Coral Gables who co-authored the study. “It was one of the things that made the Keys so special,” he said. “Just a big, bold, beautiful plant.”

Worldwide sea levels have climbed since 1900 by some 1.5 millimeters a year, a pace that is unprecedented in at least 3,000 years and generally attributable to melting ice sheets and glaciers and also the expansion of the oceans as their temperatures warm. Since the middle of the 20th century the rate has gained speed, exceeding 3 millimeters a year since 1992.

In the South the pace has quickened further, jumping from about 1.7 millimeters a year at the turn of the 20th century to at least 8.4 millimeters by 2021, according to a 2023 study published in Nature Communications based on tidal gauge records from throughout the region. In Pensacola, a beachy community on the western side of the Florida Panhandle, the rate soared to roughly 11 millimeters a year by the end of 2021.

In the South the trajectories would fall within and in some places exceed NOAA’s “high” scenario, according to the Nature Communications study. Further acceleration in the region would go as far as to threaten national security and outpace adaptation measures, the report warned.

The data suggest that by 2050 the sea level rise in Florida would correspond with NOAA’s “intermediate,” “intermediate-high” and “high” scenarios, according to the study.

Researchers at the Woods Hole Oceanographic Institution want to dump 6,600 gallons of sodium hydroxide, otherwise known as caustic soda or lye, into the ocean off the coast of Cape Cod in an effort to slow climate change.

The unusual plan will likely face significant headwinds, not just from US regulators but from local fishing communities and environmentalists as well...

...critics remain skeptical and concerned about the possible risks involved.