As the ocean carbon sink flattens, new research reveals how the biochemical impacts of warming and stratification are fundamentally compromising the sea’s ability to sustain life and regulate climate.
Two other compounding problems relate to nutrient transfer to higher trophic levels from overfishing and ocean warming, firstly warming in places reduces plankton size while increasing metabolic demand of pelagic grazers.
secondly overfishing reduces overall grazing capacity and trophic level transfer. I was having this discussion with Dave Beck on Menhaden fishing in the Gulf of Mexico where a sustainable fishing quote was actually stabilizing a 70% reduction in nutrient distribution. Total mass has shrunk since pre industrial fishing 2-3x and the total size of the fish has shrunk approx. 15% so they have a 38% reduction in total body mass. This has lead to a reduction in algal feeding and nutrient redistribution from approx.. 150mt per year down to 44mt. this flows on to a static build up of over 100mt a year in these outfall zones that is not being redistributed through the food chain and through the ocean.
When one looks at the examples of other pelagic species the results speak for themselves from krill to herring, what we call sustainable due to breeding capacity has little reflection on the oceans stability and if these trends you indicate above continue this will compound the problem.
Hi Theodore, You’re absolutely right, fisheries impacts are exacerbating these physical and biochemical aspects. The data you shared is very worrying and as you know will have a large impact on downstream weather, cloud and rainfall, even well away from the coastline.
I’ve been wondering when this stagnation issue might come up. Would it ever result in the ocean becoming noticeably smelly? If so, how long might that take? We need good science people will understand!
My many years of trying to communicate how the compound growth of organized systems naturally destabilizes and collapses them, just as if you walk ever faster you’ll trip and fall. We’ve grown several whole brilliant civilizations to collapse that way, most notable the Bronze Age Atlantis, Greece2, and Rome, all driven mad by it like we are!
I don’t know why it doesn’t get across that boundless reorganizing acceleration is suicidal, but clung to as normal throughout the world by the financial sectors inparticular.
Thanks for this. Sediment feedback deserves a mention, too. Once a dead zone establishes, anoxic conditions trigger phosphorus release from the seabed — iron-bound phosphate that was locked in the sediment for decades suddenly becomes bioavailable again. That fuels new blooms on top of the stratification-driven ones you're describing, and the decomposition of those blooms drives oxygen lower still. The Baltic has been running this loop for years now, and some of the Gulf of Mexico zones show the same signature.
Each of these stressors — deoxygenation, acidification, warming — is bad on its own, but they don't add, they multiply. The sediment phosphorus release is a good example: it only kicks in once oxygen drops below a threshold, but once it does, it accelerates everything else. The system builds its own trap door.
The last time I checked, a euxinic (anoxic containing H2S - hydrogen sulfide - highly toxic) water mass had formed in the deepest parts of the Baltic Sea with a huge oxygen dept of the water (needs lots of oxygen before it can start to oxygenate the water as it first used by microbes that use it for e.g. nitrification).
I bet the Baltic will at one point starts to outgase H2S - just an exceptional storm needed at one point…
All these flooding events start to encroach the Baltic - seasonal with huge inflows of freshwater and nutrients into the Basin.
Also summer marine heatwaves will become exceptional.
Also last from what I know cyanobacteria blooms still on the rise - large increase in some studies since the 20th century - further other HAB species also start to bloom now in the basin since some two decades.
Also macroalaga like Ulva are spreading in the Baltic - lots of biomass and nutrient accumulation will happen in the Basin
Also there seems to be a signal with annual ventilation events - colder oxygen rich water entering the Baltic Sea flushing oxygen into the deep layers which did not happen in some recent years.
IMO the Baltic Sea will make central Europe understand that you should not fuck around with the oceans…
Its all about nutrient accumulation, self sustained recycling, and N fixation in this basin - maybe even Trichodesmium enters one warmer day the carnage…
The Baltic Sea is maybe the marginal sea that will show us what microorganisms in the oceans are able to do…
Here the Marmara Sea - only to show what is possible already in other systems…
Would interest me how large the methane emissions are - significant or not?
How many years will it likely take foe the ocean to become noticeably smelly?
Already happening:
https://www.bbc.com/future/article/20250710-the-summer-slime-threatening-turkish-beaches
Or take this one:
https://www.theguardian.com/environment/ng-interactive/2026/mar/14/algal-bloom-south-australia-update-one-year-on
This system is now in free fall…
Two other compounding problems relate to nutrient transfer to higher trophic levels from overfishing and ocean warming, firstly warming in places reduces plankton size while increasing metabolic demand of pelagic grazers.
secondly overfishing reduces overall grazing capacity and trophic level transfer. I was having this discussion with Dave Beck on Menhaden fishing in the Gulf of Mexico where a sustainable fishing quote was actually stabilizing a 70% reduction in nutrient distribution. Total mass has shrunk since pre industrial fishing 2-3x and the total size of the fish has shrunk approx. 15% so they have a 38% reduction in total body mass. This has lead to a reduction in algal feeding and nutrient redistribution from approx.. 150mt per year down to 44mt. this flows on to a static build up of over 100mt a year in these outfall zones that is not being redistributed through the food chain and through the ocean.
When one looks at the examples of other pelagic species the results speak for themselves from krill to herring, what we call sustainable due to breeding capacity has little reflection on the oceans stability and if these trends you indicate above continue this will compound the problem.
Hi Theodore, You’re absolutely right, fisheries impacts are exacerbating these physical and biochemical aspects. The data you shared is very worrying and as you know will have a large impact on downstream weather, cloud and rainfall, even well away from the coastline.
I’ve been wondering when this stagnation issue might come up. Would it ever result in the ocean becoming noticeably smelly? If so, how long might that take? We need good science people will understand!
My many years of trying to communicate how the compound growth of organized systems naturally destabilizes and collapses them, just as if you walk ever faster you’ll trip and fall. We’ve grown several whole brilliant civilizations to collapse that way, most notable the Bronze Age Atlantis, Greece2, and Rome, all driven mad by it like we are!
I don’t know why it doesn’t get across that boundless reorganizing acceleration is suicidal, but clung to as normal throughout the world by the financial sectors inparticular.
Synapse9.com/signals. Changing too fast is a signal to slow down or break down!
Thanks for this. Sediment feedback deserves a mention, too. Once a dead zone establishes, anoxic conditions trigger phosphorus release from the seabed — iron-bound phosphate that was locked in the sediment for decades suddenly becomes bioavailable again. That fuels new blooms on top of the stratification-driven ones you're describing, and the decomposition of those blooms drives oxygen lower still. The Baltic has been running this loop for years now, and some of the Gulf of Mexico zones show the same signature.
Each of these stressors — deoxygenation, acidification, warming — is bad on its own, but they don't add, they multiply. The sediment phosphorus release is a good example: it only kicks in once oxygen drops below a threshold, but once it does, it accelerates everything else. The system builds its own trap door.
Thx a lot for explanation.
This feedback will become mighty
The last time I checked, a euxinic (anoxic containing H2S - hydrogen sulfide - highly toxic) water mass had formed in the deepest parts of the Baltic Sea with a huge oxygen dept of the water (needs lots of oxygen before it can start to oxygenate the water as it first used by microbes that use it for e.g. nitrification).
I bet the Baltic will at one point starts to outgase H2S - just an exceptional storm needed at one point…
All these flooding events start to encroach the Baltic - seasonal with huge inflows of freshwater and nutrients into the Basin.
Also summer marine heatwaves will become exceptional.
Also last from what I know cyanobacteria blooms still on the rise - large increase in some studies since the 20th century - further other HAB species also start to bloom now in the basin since some two decades.
Also macroalaga like Ulva are spreading in the Baltic - lots of biomass and nutrient accumulation will happen in the Basin
Also there seems to be a signal with annual ventilation events - colder oxygen rich water entering the Baltic Sea flushing oxygen into the deep layers which did not happen in some recent years.
IMO the Baltic Sea will make central Europe understand that you should not fuck around with the oceans…
Its all about nutrient accumulation, self sustained recycling, and N fixation in this basin - maybe even Trichodesmium enters one warmer day the carnage…
The Baltic Sea is maybe the marginal sea that will show us what microorganisms in the oceans are able to do…
Here the Marmara Sea - only to show what is possible already in other systems…
Would interest me how large the methane emissions are - significant or not?
https://www.youtube.com/watch?v=5-NQbI7WAzY