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Ocean Clean Up Groups
'Ocean darkening' a cause for concern - scientists
'Ocean darkening' a cause for concern - scientists
Among the multifaceted crises faced by people and the planet, climate change stands as perhaps the most formidable of all. Sea-level rise is unarguably foremost among its impacts. For low-lying and Small Island Developing States, no issue is more pressing or consequential. The IPCC estimates that, by 2050, global sea levels will rise between 15 and 30 centimeters, on average, with greater increases expected in equatorial regions, particularly the Pacific. Extreme sea-level events – which used to occur once every century – could become an annual phenomenon by the close of this century. Close to one billion people living in low-lying coastal zones will be directly affected due to rising sea levels and climate impacts.
This issue is multidimensional and extends far beyond coastal populations – it affects every continent and region, leaving no one immune from potential catastrophe. Sea-level rise will impact communities in Small Island Developing States, as well as coastal states, and many more millions will have to adapt to floods, storms, erosion, and forced displacement -- UNGA, Sept 2024.
Coral Reefs
Coral Reefs
MANGROVE FORESTS
MANGROVE FORESTS
Deep Sea Trawling?minning Carbon Capture
Deep Sea Trawling?minning Carbon Capture
Ocean acidification has been identified in the Planetary Boundary Framework as a planetary process approaching a boundary that could lead to unacceptable environmental change. Using revised estimates of pre-industrial aragonite saturation state, state-of-the-art data-model products, including uncertainties and assessing impact on ecological indicators, we improve upon the ocean acidification planetary boundary assessment and demonstrate that by 2020, the average global ocean conditions had already crossed into the uncertainty range of the ocean acidification boundary. This analysis was further extended to the subsurface ocean, revealing that up to 60% of the global subsurface ocean (down to 200 m) had crossed that boundary, compared to over 40% of the global surface ocean. These changes result in significant declines in suitable habitats for important calcifying species, including 43% reduction in habitat for tropical and subtropical coral reefs, up to 61% for polar pteropods, and 13% for coastal bivalves. By including these additional considerations, we suggest a revised boundary of 10% reduction from pre-industrial conditions more adequately prevents risk to marine ecosystems and their services; a benchmark which was surpassed by year 2000 across the entire surface ocean. Source: Ocean Acidification: Another Planetary Boundary Crossed Helen S. Findlay, Richard A. Feely, Li-Qing Jiang, Greg Pelletier, Nina Bednaršek First published: 09 June 2025 https://doi.org/10.1111/gcb.70238
The seasonal concentration of chlorophyll on our planet. A superb animation from NASA https://buff.ly/3AGGHHm
These satellite data reveal the annual cycle of plant life on land and in water. Chlorophyll is a green pigment and is therefore present in all plants. Especially in these large "ocean forests", which allow us to breathe.
Thanks to its small biological solar panels called chloroplasts, chlorophyll allows the conversion of the sun's energy into sugar and then into oxygen.
This animated map shows us its planetary distribution, which contracts and spreads out on land and in the oceans, to the rhythm of the seasons. The tiny oceanic organisms called phytoplankton are the planet's largest source of oxygen. During the northern hemisphere winter, plant life is minimal and receives little sunlight. The plants are actually dormant and flourish in the summer. Conversely, in the Southern Ocean, plant life is revealed in winter with dark green colors on land and in the ocean. Photosynthesis (from the Greek phōs "light" and sýnthesis "combination"), is literally a "combination of light".
The first organisms capable of capturing sunlight are 3.8 million years old, just after the formation of the Earth, they are the cyanobacteria that still exist. See my post on the Baltic bloom They worked, stubbornly, one by one for nearly a billion years until they produced a major ecological upheaval 2.45 million years ago.
The Great Oxidation, the origin of our oxygenated atmosphere. These single-celled beings are the first organic carbon sinks in history, and in this sense, the ancestors of terrestrial forests. And our ancestors to all.
Vegetative plankton produce almost half of the oxygen we breathe. It plays a central role in carbon fluxes and climate regulation. Its other role is to supply food to marine food webs.
According to MIT, the concentration of phytoplankton can be estimated by its colour. Scientists are unanimous, our oceans are turning green! 🟢 https://buff.ly/4bM91EP
Good news! The increase in carbon will promote the growth of phytoplankton on the surface. Except that the increase in temperature will lead to a more "stratified" ocean, with warmer surface waters that will mix less with the cold waters of the depths.
The color of the ocean will change and the ocean food chain will also change. But chlorophyll is not expected to disappear anytime soon.
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The oceans are turning green because of a massive regime shift from carbonate-based plankton such as coccolithophores and diatoms to cyanobacteria and dinoflagellates. The cyanobacteria dinoflagellates are not good food sources for zooplankton, and many of them are toxic. This is not good news; it spells the end of most marine life, including seals, fish, criustaceans, and whales, and the loss of a food supply for around 3 billion people.
Cyanobacteria and dinolflagellates do not produce oils to maintain the SML layer; this means we have high atmospheric water vapour pressure, torrential downpours, high wind velocity, and extreme fluctuations in the climate. The Earth is no longer a Blue Planet but a toxic green planet....
THE MARINE CARBON CYCLE
THE MARINE CARBON CYCLE
Many marine organisms need carbonate—dissolved carbon dioxide—in order to build their shells. But too much carbon dioxide can upset the balance.
When carbon dioxide is absorbed by the ocean, it dissolves into carbonic acid and splits into two different types of ions, or charged atoms: hydrogen ions and bicarbonate ions.
The hydrogen ions combine with carbonate ions in seawater to form even more bicarbonate ions. As the amount of carbon dioxide in the atmosphere increases, the concentration of hydrogen ions in the water also increases, and more carbonate ions join to form bicarbonate ions. This means there is less carbonate available for organisms that use it to grow—corals, mussels, kina and starfish.
The concentration of hydrogen ions in seawater determines its pH, or ‘potential of hydrogen’.
The pH scale runs from zero (the strongest acids, such as hydrochloric acid) to 14 (the strongest bases, such as lye). Neutral solutions, such as distilled water, sit in the middle of the scale at 7. Seawater should be slightly basic, with a pH of around 8.2, but globally it has dropped below 8.1 over the past two centuries. While a change of 0.1 doesn’t sound like much, the pH scale is logarithmic, like the Richter scale, so this represents a 10-fold increase in acidity. The Munida time series shows that pH in New Zealand’s coastal waters has been decreasing at the same rates observed in the Northern Hemisphere. If this trend continues, the open ocean will reach pH levels of 7.8 by the end of this century, but in some areas along the coast, it already drops as low as 7.7.
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