#warmingoceans — Public Fediverse posts
Live and recent posts from across the Fediverse tagged #warmingoceans, aggregated by home.social.
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NOT so harmless...
Excerpt: "Introducing #KareniaMikimotoi
"The species responsible for recent events in #SouthAustralia beaches, #KMikimotoi, causes harmful #algal blooms in #Asia, #Europe, #SouthAfrica and #SouthAmerica, as well as #Australia and #NewZealand. These blooms all caused fish deaths, and some also caused #breathing difficulties among local #beachgoers.
"The most drastic of these K. mikimotoi blooms have occurred in China over the past two decades. In 2012, more than 300 square kilometres of abalone farms were affected, causing about A$525 million in lost production.
Explaining the toxic effects
"Microalgae can damage the gills of fish and shellfish, preventing them from breathing. This is the main cause of death. But some studies have also found damage to the gastrointestinal tracts and livers of fish.
"Tests using fish gill cells clearly show the dramatic toxic effect of K. mikimotoi. When the fish gill cells were exposed to intact K. mikimotoi cells, after 3.5 hours more than 80% of the fish cells had died.
"Fortunately, the toxin does not persist in the environment after the K. mikimotoi cells are dead. So once the bloom is over, the marine environment can recover relatively quickly.
"Its toxicity is partly due to the algae’s production of 'reactive oxygen species', reactive forms of oxygen molecules which can cause the deaths of cells in high doses. K. mikimotoi cells may also produce lipid (fat) molecules that cause some toxic effects.
"Finally, a very dense bloom of microalgae can sometimes reduce the amount of dissolved oxygen in the water column, which means there is less oxygen for other marine life.
"The human health effects are not very well known but probably relate to the reactive oxygen species being an irritant.
"K. mikimitoi cells can also produce 'mucilage', a type of thick, gluey substance made of complex sugars, which can accumulate #bacteria inside it. This can cause 'sea foam', which was evident on beaches last week.
"A question for many people is whether increasing water temperatures make blooms of K. mikimotoi more likely.
"Another concern is whether nutrient runoff from farms, cities and #aquaculture could cause more harmful algal blooms.
"Unfortunately, for Australia at least, the answer to these questions is we don’t know yet. While we know some harmful algal blooms do increase when nutrient runoff is higher, others actually prefer fewer nutrients or colder temperatures.
"We do know warmer water species seem to be moving further south along the Australian coastline, changing #phytoplankton species abundance and distribution.
"While some microalgal blooms can cause bioluminescence that is beautiful to watch, others such as K. mikimotoi can cause skin and respiratory irritations.
If you notice discoloured water, fish deaths or excessive sea foam along the coast or in an estuary, avoid fishing or swimming in the area and notify local primary industry or environmental authorities in your state."
#OceanHealth #Beaches Algae #SeaFoam #HABs #HarmfulAlgaeBlooms #KareniaMikimotoi #WarmingOceans #Radioactivity #NutrientRunoff #OceansAreLife #ROS #SkinIrritations #RespiratoryIrration #ReactiveOxygenSpecies #DeadZones
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"Corals Spin Tiny Vortices to Get Oxygen, but Not if It’s Too Hot
At first glance, corals present as little more than colorful rocks — piles of lobes, stalagmites, and branches poking out from the seafloor.
They are anything but. Corals are complex creatures that form enduring colonies, and just like other animals they need oxygen to live. Across the living surface of coral, a frantic dance of survival takes place, invisible to our eyes and unknown to science before 2014. The tiny dancers are hairlike cilia, and new research into these microscopic structures is revealing just how active corals are in determining their own fate.
Corals aren’t fortunate enough to have a consistent supply of oxygen, and they can’t change location to seek it out. During the day, the tiny polyps that make up a coral colony get plenty of oxygen from the symbiotic algae that photosynthesize within their tissues. But at night that process stops, and a coral polyp’s only source of oxygen is the water around it. Then it’s do or die for the cilia. Using mechanisms scientists are still trying to understand, the cilia wave around to generate fast-moving vortices of water that circulate oxygen to the coral’s outer tissues, in addition to helping keep the colonies free of sediment.
A study published in Science (opens a new tab) in May 2026 provides new insight into how organisms with no brain or musculoskeletal system can generate and regulate this process — and what happens when the water around them warms up. Warmer water naturally carries less oxygen, which prompts corals to move their cilia faster and faster, as if gasping for breath. Above a certain temperature, the system starts to work against itself; the furious beating of cilia uses up any oxygen the coral’s tissues can absorb, and then the polyps can suffocate in the less oxygenated water. Biophysicists, marine biologists, mathematicians, and modelers are now collaborating to better understand the physiological and hydrodynamic forces at work, and how they correlate with bleaching patterns, coral disease, and mass die-offs."
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#Jellyfish are taking over the world – and #ClimateChange could be to blame
Jan 8, 2019
by Sean Fleming
Senior Writer, Forum Stories"For 500 million years, jellyfish have been part of the maritime #ecosystem, but now they’re poised to take over the earth.
"They have no brain, no eyes, no spine, not even blood, but they have a remarkable capacity to reproduce and can pack an impressive sting, both literally and figuratively.
"Most recently, vast numbers of bluebottle jellyfish were pushed ashore by unusually strong winds and spells of hot weather in #QueenslandAustralia, stinging thousands of people and forcing the closure of popular swimming spots. About 13,000 stings were recorded in the past week.
"In June last year, over the course of just one week, over 1,000 people were stung in Volusia County, #Florida, following a period of exceptionally prolific jellyfish blooms. The explosion in their numbers has been attributed to warming seas and even increased pollution; unlike many other marine creatures, jellyfish can cope with reduced oxygen levels.
Small but deadly – at least some of the time
"Typically, jellyfish range in size from 1cm to 40cm. But they can be significantly larger – the #LionsManeJellyfish, for example, can reach 1.8 metres wide, with tentacles over 15 metres long.
"For the most part, the sting of a jellyfish is more unpleasant than it is harmful. The pain comes from venom delivered via millions of microscopic barbs in the creatures’ tentacles. Most jellyfish stings will only have a localized effect on the victim – redness, swelling, and discomfort where the barbs make contact with the skin.
"Some, however, will prompt a systemic, whole body, reaction. These may take several hours to emerge and can include symptoms such as headaches, nausea and drowsiness.
"In rare cases, the sting can be fatal. This is true of the #BoxJellyfish, which is spreading into waters that had previously been too cool to support it; its venom causes a severe reaction that can cause death within minutes.
A force of destruction
"But these booming jellyfish populations are doing far more harm than ruining people’s trips to the beach. In fact, the scope of their disruption has extended far beyond the water’s edge.
"In 2011, both reactors at the #TornessNuclearPowerPlant in #Scotland were shut down after an invasion of jellyfish started blocking the cooling filters. Two years later, the jellyfish struck again – this time in #Sweden. They forced the closure of the #OskarshamnNuclearPowerPlant, which contains the world’s largest boiling-water reactor.
"The island of Luzon, home of the Phillippines’ capital Manilla, suffered a blackout in 1999 due to jellyfish, and in 2006 the #USSRonaldReagan, a nuclear-powered aircraft carrier, was brought to a standstill by thousands of the little creatures. And while these events may stand out as exceptions, they are increasing in both scale and frequency.
"From sea-bed diamond mining in Namibia to salmon farming in Ireland, even jeopardising the sustainability of beluga caviar farming in the Caspian Sea, jellyfish are as destructive as they are abundant. And that abundance is being caused by a variety of factors, many of which are related to human activity.
Some like it hot
"Over the last hundred or so years, the average surface temperature of the world’s seas has risen by about 0.9°C. As the oceans get warmer, marine animals are able to spread into areas that had historically been too cold. Oxygen levels in the sea have fallen by around 2% over the last 50 years, due to rising temperatures and #pollution [including #NuclearOceanDumping, which reduces oxygen levels]
"Jellyfish can thrive in areas with lower oxygen levels, where other animals suffer. But there are other factors at work, too. Fishing has depleted the global stocks of some of the jellyfish’s natural predators – such as #tuna and #swordfish – and some they compete with for food – such as anchovies. With more food and fewer predators, some jellyfish populations can grow unchecked.
"In the #BlackSea, unchecked population growth is precisely what’s happened. #AnchovyFishing in the region had caused harm to the Black Sea’s ecosystem by the time stowaway jellyfish made the journey there from the eastern seaboard of the USA. Most likely transported in the ballast water of ships that made the crossing, 1982 saw the arrival of the warty comb jelly. By 1990, there were 900 million tons of them in the Black Sea.
"There are believed to be around 200 different species of jellyfish, not all of which can sting, and some are considered edible. This could offer one potential, and creative, approach toward dealing with an over-abundance of jellyfish – co-opting them onto our dinner plates." [That's one way to deal with invasive species -- eat them into extinction!]
Source:
https://www.weforum.org/stories/2019/01/how-an-explosion-of-jellyfish-is-wreaking-havoc/#GlobalWarming #WarmingOceans
#ChangingOceans #OceansAreLife #OceanTemperatures #ClimateCrisis #Overfishing #NoDeepSeaMining #NoNewNukes #NoNukes #NoNukesForAI #Oskarshamn #Torness -
Half of all #eelgrass in #CascoBay has died within last four years, experts say
Eelgrass, according to Friends of Casco Bay, is home to juvenile lobster and fish. Without eelgrass, much of Maine's seafood economy loses its base, they said.
By Jack Molmud
March 29, 2023SOUTH PORTLAND, #Maine — According to a report from Friends of Casco Bay, 54 percent of all eelgrass meadows in Casco Bay have died off since 2018.
"This comes as the 2022 to 2023 winter saw water temps reach four degrees above average.
"'My first response was it's heartbreaking,' Will Everitt, the executive director of Friends of Casco Bay said. 'My second response was now is the time we have to do more than ever to protect the bay.'
"Everitt said eelgrass is dying due to a combination of consequences from the warm water.
"Warm water attracts more invasive #GreenCrabs, which cut the eelgrass and eat softshell crabs, he said. This disturbs the naturally-occurring species, he said.
"'When we have a really cold winter it can kill back the green crabs,' Everitt said.
"He added a warm winter won't kill as many green crabs, allowing them to reproduce and spawn more green crabs for summer and fall.
"'The loss of this is tragic and could have a huge impact on our coastal waters,' Everitt said.
"Everitt added the #WarmingOceans in Maine also result in more frequent #AlgaeBlooms, which prevent the eelgrass from accessing proper sunlight to grow.
"Fewer eelgrass meadows mean fewer lobsters in inshore waters, he added.
"'A number of critters in the bay depend on this... the warming waters are going to do a number on this if it continues,' Everitt said.
"If the situation continues to worsen, Everitt suggested experts would recommend planting eelgrass from more southern states so that subspecies can handle the warmer temperatures Maine is set to experience."
#FriendsOfCascoBay #SaltMarshes #SaveTheWetlands #EelGrass #SaveTheWetlands
#SaveTheMarshes #ProtectNature #NewEngland #GulfOfMaine