#warmingoceans — Public Fediverse posts
Live and recent posts from across the Fediverse tagged #warmingoceans, aggregated by home.social.
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#SeaIce loss in the #Arctic has triggered a critical #TippingPoint that's destroying the food chain
Story by Sascha Pare, June 8, 2026
"The Arctic Ocean has crossed a tipping point that is wreaking havoc on the region's food chain, with potentially dire consequences for commercial fishing and the ocean's capacity to soak up carbon, a new study reports.
"Scientists found that vast areas of melting sea ice in the Arctic are leading to a significant reduction in nitrate, a key nutrient that forms the base of the marine food web and thus underpins important regional fisheries. As the ice disappears, more light hits the water's surface, promoting the growth of microscopic, plant-like organisms called phytoplankton. When phytoplankton die, their cells sink to the seafloor and are decomposed by nitrate- and oxygen-consuming bacteria.
"The new study, published May 28 in the journal Communications Earth & Environment, found that the bacteria are consuming more nitrate than the Arctic ecosystem can withstand.
"This effect, known as 'denitrification,"' is irreversible under current climate conditions because we have passed a threshold where so much sunlight reaches the ocean that it's supercharging phytoplankton's productivity, said Marta Santos-García, a doctoral student of Arctic marine biogeochemistry at the University of Edinburgh in Scotland and the first author of the study.
" 'Even if sea ice were to increase temporarily, the Arctic nutrient system responds over much longer timescales,' Santos-García told Live Science in an email. 'Short-term increases in sea ice would be unlikely to rapidly reverse the decline in nitrate inventories, which may take much longer to recover.'
"Dropping nitrate levels may eventually come back to bite phytoplankton, because these tiny organisms need nitrate to carry out photosynthesis. As a result, the transition to a low-nitrate regime could accelerate #ClimateChange, as nitrate plays an essential role in the ocean's biological pump, which takes #CarbonDioxide from the atmosphere via photosynthesis and locks it away at depth when #phytoplankton and the animals that eat it die.
" 'With nutrients such as nitrate in limited supply this mechanism cannot work effectively,' Santos-García said.
"To understand ecosystem changes in the Arctic, the researchers analyzed two decades of data from the Fram Strait, a passage between Greenland and Svalbard, Norway, that is the main gateway through which Arctic waters flow into the Atlantic Ocean. They found a sharp decline in nitrate levels in this region after 2009, which coincided with a dramatic reduction in Arctic sea ice and a gradual shift in phytoplankton communities toward smaller species that can cope with low nutrient levels.
" 'Shifts towards smaller phytoplankton have already been observed in parts of the Arctic, although these changes have not previously been linked to nitrate losses,' Santos-García said. 'This matters because smaller phytoplankton are generally less efficient at transferring energy up the food web. More of the energy is recycled within microbial communities rather than being passed on to larger zooplankton, fish, seabirds, and marine mammals.'
"Phytoplankton sit at the very bottom of the marine food chain, so the impacts of nitrate depletion will ripple through the Arctic ecosystem, impacting species at the highest levels. This could also affect fisheries in regions that depend on Arctic nutrient exports, such as the North Atlantic. But pinpointing what will happen in ecosystems downstream of the Arctic Ocean requires more research, Santos-García said.
"For years, researchers thought the long-term impact of sea ice loss in the Arctic would be an increase in phytoplankton, because more organisms can bathe in sunlight and multiply when the sea ice extent is small. However, the increase in phytoplankton since 2009 has depleted nitrate levels enough to limit future phytoplankton growth.
"Whereas phytoplankton proliferation used to be limited by how much sunlight reached surface waters, it is now controlled by nitrate levels. Therefore, nitrate must be considered as a key driver of future changes in the Arctic, Santos-García said.
" 'As nitrate is the nutrient that limits Arctic productivity, understanding these changes is therefore important not only for Arctic communities and ecosystems, but also for improving projections of future climate change,' she said."
Archived version:
https://archive.ph/E1Dlw#ClimateChange #TippingPoint #GlobalWarming #WarmingOceans #ArcticEcosystems #SeaIce #OceansAreLife
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#Algal #Toxins emerge as a new concern in #Alaska’s Northern Bering Sea
Locals who depend on the sea for food and culture are trying to understand the risks to traditional foods and wildlife populations in a region undergoing myriad changes
by Yereth Rosen, Alaska Beacon, May 31, 2026 via #ICTNews
Excerpt: "For countless generations, people of the #BeringStrait region have relied on the food they harvest from the sea without worrying about #HarmfulAlgalBlooms [#HABs] that threaten seafood eaters in warmer and more southern latitudes.
"Now, as the Northern Bering Sea undergoes cascading effects of a warming climate, algal risks pose a new challenge.
"The change has been dramatic.
"And it has prompted a change in the way #Nome youth grow up learning about collecting food from the waters around their home. In early April, Nome high school students traveled to Bethel with their science teacher, where they presented their research at the Western Alaska Interdisciplinary Science Conference held by Alaska Sea Grant.
"Algal toxins were present, at very low but detectable levels, in fish they eat.
"Sophomore Audrey Bruner-Alvanna was among the group of student researchers. She said young people are concerned about algal blooms, which proliferate in warmer conditions, and their potential effects on wild food resources.
" 'Because, you know, as the climate changes, as the world gets warmer and stuff, there’s going to be more of these toxins and stuff during summer,' she said. 'I feel like a lot of people that I’ve talked to have been wondering about how our subsistence is going to change in the future based on all of that.'
"The student research came about after one of the nation’s densest and biggest concentrations of toxin-producing Alexandrium algae ever documented burst forth in the waters of the Bering Strait region in 2022.
"Until the appearance of the 'massive bloom, the most toxic bloom, the longest-persisting bloom in the U.S.,' local people barely knew what harmful algal blooms or #Alexandrium are, said Emma Pate, president of the Nome Eskimo Community, the local tribal government.
" 'So we had to figure things out and learn really fast,' Pate said during an October 'Strait Science' presentation hosted by the University of Alaska Fairbanks’ Nome campus."
Read more:
https://ictnews.org/news/algal-toxins-emerge-as-a-new-concern-in-alaskas-northern-bering-sea/#ClimateChange #ToxicAlgae #UniversityOfAlaska #TraditionalFoodSources #NativeAlaskans #WarmingOceans #AlexandriumAlgae
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More victims of #ClimateChange and #WarmingOceans. Also, #KrillHarvesting has got to STOP!
Scientists Alarmed as #Whales Suddenly Going Silent
"When you really break it down, it’s like trying to sing while you're starving."
Aug 1, 10:27 AM EDT by Victor Tangermann
"Researchers are alarmed after noticing a significant drop in the number of vocalizations from #BlueWhales.
"As National Geographic reports, scientists used specialized underwater hydrophones, meaning the aquatic version of microphones, to record and trace the sounds of marine life, allowing them to analyze the impact human activity is having on various species.
"However, as detailed in a study published in the journal PLOS One, devastating heat waves have triggered worrying changes over the past decade, allowing #ToxicAlgae to bloom and undermine food sources for whales.
" 'It caused the most widespread poisoning of marine mammals ever documented,' coauthor and Monterey Bay Aquarium Research Institute biological oceanographer John Ryan told NatGeo. 'These were hard times for whales.'
"As a result, blue whale vocalizations dropped by almost 40 percent, according to the study, with populations of #krill and #anchovy collapsing.
" 'When you really break it down, it’s like trying to sing while you're starving,' Ryan explained. 'They were spending all their time just trying to find food.' "
Read more:
https://futurism.com/scientists-alarmed-whales-silent#OceansAreLife #Overfishing #FoodIsLife #Extinction #MarineLife #MarineHeatWaves #HeatBlob #GlobalWarming
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Why the #GulfOfMaine Surface Ocean Waters are Warming Faster than Elsewhere
Posted on July 23, 2024Written by Rob Moir, Ph.D. No Comments
"None of us are strangers to the reports of the Gulf of Maine heating 97% faster than the world’s oceans. However, the actual reasons for this can be lost in the constant headlines about global warming and rising greenhouse gases. To explain this extraordinary phenomenon, let’s look closely at four factors: surface seawater temperatures, heat severity, air temperature, and rainfall, monthly for five years."
#WarmingOceans #ClimateCatastrophe #Climate #Maine #NewEngland #AlgalBloom #HABs #ToxicAlgae
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Six rare #sawfish deaths in 7 days have scientists baffled amid bizarre #Florida fish behavior
“There is no concrete, conclusive proof of what is happening yet and that is still to be determined, which is quite terrifying.” said Gregg Furstenwerth, a lifelong diver in the Florida Keys. “If it continues, it is going to be the end of this #ecosystem as we know it.”
By Jen Christensen, CNN
Published Apr 12, 2024
"Most tests for toxins have been negative, but scientists have seen an unusually high number of #algae called gambierdiscus that can produce a wide variety of #neurotoxins that can be harmful to fish and dangerous to humans.
#Gambierdiscus is normally found in tropical and subtropical waters all around the world, but the algae can grow quickly when waters are warmer than usual. The climate crisis has brought record hot temperatures to the waters around southern Florida."
#SpinningFish #ClimateChange #WarmingOceans #OceanTemperatures #ToxicAlgae #SouthFlorida #WaterIsLife #OceanEcosystem #Collapse #EcosystemCollapse #Extinction #FishDeaths