Forams are only 5% of total marine plankton biomass - some may move poleward - some increase - overall may decrease by less than 10% in a warmer world - remaining 95% of marine plankton is increasing
Forams, which have tiny shells, form only 5% of all the microorganisms that turn light into organics in the sea. The remaining 95% is increasing in biomass. And Forams do NOT vanish. They just reduce slightly in biomass by < 10% but that is a mix of some staying in place and increasing and some moving towards the poles. Most of the biomass is algae and they are increasing.
This is the article I’m debunking - the title is clickbait - the TITLE LIES. I’ve added annotations in caps to show to you how the title is telling you lies about what the finding was.
Forams form only 5% of total phytoplankton biomass (phytoplankton means they turn light into organics). Forams have tiny shells a bit like a miniature shellfish. Also it is about whether they just migrate to cooler waters or they can adapt in place. Some of them form partnerships with algae and those are the best able to adapt as the oceans warm. Looking at those two effects they find a less than 10% reduction in the forums at 2 C. But almost all the biomass is algae not forams. Only 5% of all biomass is forams so that less than 10% means < 0.5% reduction in the total biomass of all the phytoplankton.
If you look at marine plankton generally, they are INCREASING in mass with global warming. This is a recent study in the Sargasso sea. Surface layers have the same total carbon mass as before but are getting less green - that is probably because they spend more time in sunnier water as the ocean layers mix less in a warmer world. Lower levels are increasing in mass.
. ‘Invisible forest’ of algae thrives as ocean warms
Here is a “The Conversation” post about those thriving marine algae: As the oceans warm, deep-living algae are thriving – with major potential effects for the marine ecosystem
Paper here
QUOTE Over the last decade, the subsurface phytoplankton biomass has increased in response to warming, whereas the surface phytoplankton have altered their carbon-to-chlorophyll ratio with minimal change in their carbon biomass.
So what are the new findings about forams? Back to this study that has hit the news recently, what did it find?
This is only looking at forams, which have a shell of calcium carbonate like shellfish, not algae which adapt fast to warming.
Many forams have algae partners that live with them (symbiote) and those can adapt fast to warming. because of the algae
Forams that can't adapt so well will migrate to colder waters.
Some populations of forams increase in biomass.
They predict that at 2 C the total biomass of forams will be reduced by 7.2% and at 1.5 C by 5.7%.
QUOTE STARTS With a warming of 1.5, 2, 3, and 4 °C by 2100, foraminifera biomass is projected to reduce further by 5.7, 7.2, 10.6 and 15.1%, respectively
...
As observed since the pre-industrial age, planktic foraminifera in the mid-to-high latitudes will migrate polewards in the future.
Symbiont-barren spinose foraminifera, such as G. bulloides, will increase their biomass standing stocks (hereafter, biomass) in the Southern Ocean and the North Atlantic, benefitting from niche expansion (Fig. 2c) into a habitat in which symbiont-barren non-spinose species dominate today.
The biomass of warm-adapted symbiont-obligate spinose will increase in the North subpolar regions and subantarctic zones (Fig. 2c), which agrees with the observations in the Arctic33 and Southern Ocean34.
...
The top-down control (grazing pressure) is typically negligible for foraminifera, owing to their small biomass
. Past foraminiferal acclimatization capacity is limited during future warming - Nature
Their cite there for the small biomass says
QUOTE STARTS
In contrast to their high abundances in sediments, they tend to grow at very low abundance in the ocean and never dominate the zooplankton community, representing less than 5 % of total microprotozooplankton abundance
. A trait-based modelling approach to planktonic foraminifera ecology
Interestingly the shells don't seem to be mainly for protection against predators and may perhaps be to protect against pathogens.
QUOTE STARTS
By constraining the model results with ocean biomass estimations of planktonic foraminifera, we estimate that the energetic cost of calcification could be about 10 %–50 % and 10 %–40 % for prolocular and adult stages respectively. Our result suggest that the shell provides protection against processes other than predation (e.g. pathogen invasion). We propose that the low standing biomass of planktonic foraminifera plays a key role in their survival from predation, along with their shell protection.
. A trait-based modelling approach to planktonic foraminifera ecology
The idea here is that at only 5% of the total biomass then it's not worthwhile for predators to specialize in eating forams.
About forams.
QUOTE STARTS
Forams, which have tiny shells, form only 5% of all the microorganisms that turn light into organics in the sea. The remaining 95% is increasing in biomass. And Forams do NOT vanish. They just reduce slightly in biomass by < 10% but that is a mix of some staying in place and increasing and some moving towards the poles. Most of the biomass is algae and they are increasing.
Forams form only 5% of total phytoplankton biomass (phytoplankton means they turn light into organics). Forams have tiny shells a bit like a miniature shellfish. Also it is about whether they just migrate to cooler waters or they can adapt in place. Some of them form partnerships with algae and those are the best able to adapt as the oceans warm. Looking at those two effects they find a less than 10% reduction in the forums at 2 C. But almost all the biomass is algae not forams. Only 5% of all biomass is forams so that less than 10% means < 0.5% reduction in the total biomass of all the phytoplankton.
The marine algae are increasing in mass with global warming. This is a recent study in the Sargasso sea. Surface layers have the same total carbon mass as before but are getting less green - that is probably because they spend more time in sunnier water as the ocean layers mix less in a warmer world. Lower levels are increasing in mass.
The Conversation post: As the oceans warm, deep-living algae are thriving – with major potential effects for the marine ecosystem
Paper here
QUOTE Over the last decade, the subsurface phytoplankton biomass has increased in response to warming, whereas the surface phytoplankton have altered their carbon-to-chlorophyll ratio with minimal change in their carbon biomass.
So about this study:
1. This is only looking at forams, which have a shell of calcium carbonate like shellfish, not algae which adapt fast to warming.
2. Many forams have algae partners that live with them (symbiote) and those can adapt fast to warming. because of the algae
3. Forams that can't adapt so well will migrate to colder waters.
4. Some populations of forams increase in biomass.
4. They predict that at 2 C the total biomass of forams will be reduced by 7.2% and at 1.5 C by 5.7%.
QUOTE STARTS With a warming of 1.5, 2, 3, and 4 °C by 2100, foraminifera biomass is projected to reduce further by 5.7, 7.2, 10.6 and 15.1%, respectively
...
As observed since the pre-industrial age, planktic foraminifera in the mid-to-high latitudes will migrate polewards in the future.
Symbiont-barren spinose foraminifera, such as G. bulloides, will increase their biomass standing stocks (hereafter, biomass) in the Southern Ocean and the North Atlantic, benefitting from niche expansion (Fig. 2c) into a habitat in which symbiont-barren non-spinose species dominate today.
The biomass of warm-adapted symbiont-obligate spinose will increase in the North subpolar regions and subantarctic zones (Fig. 2c), which agrees with the observations in the Arctic33 and Southern Ocean34.
...
The top-down control (grazing pressure) is typically negligible for foraminifera, owing to their small biomass
. Past foraminiferal acclimatization capacity is limited during future warming - Nature
Their cite there for the small biomass says
QUOTE STARTS
In contrast to their high abundances in sediments, they tend to grow at very low abundance in the ocean and never dominate the zooplankton community, representing less than 5 % of total microprotozooplankton abundance
QUOTE STARTS
By constraining the model results with ocean biomass estimations of planktonic foraminifera, we estimate that the energetic cost of calcification could be about 10 %–50 % and 10 %–40 % for prolocular and adult stages respectively. Our result suggest that the shell provides protection against processes other than predation (e.g. pathogen invasion). We propose that the low standing biomass of planktonic foraminifera plays a key role in their survival from predation, along with their shell protection.
. A trait-based modelling approach to planktonic foraminifera ecology
Interestingly the shells don't seem to be mainly for protection against predators and may perhaps be to protect against pathogens.
QUOTE STARTS
By constraining the model results with ocean biomass estimations of planktonic foraminifera, we estimate that the energetic cost of calcification could be about 10 %–50 % and 10 %–40 % for prolocular and adult stages respectively. Our result suggest that the shell provides protection against processes other than predation (e.g. pathogen invasion). We propose that the low standing biomass of planktonic foraminifera plays a key role in their survival from predation, along with their shell protection.
. A trait-based modelling approach to planktonic foraminifera ecology
The idea here is that at only 5% of the total biomass then it's not worthwhile for predators to specialize in eating forams.
About forams. Foraminifera - Wikipedia
Also to put this in context, the ocean plankton population isn’t in a steady state. These are tiny organisms with short lives that grow and spread and die very quickly. At different times of year different plankton will spread in the oceans and then others take over with seasonal cycles.
So this is about very slightly fewer forams in the mix overall in a very dynamic situation where all the species numbers are varying all the time depending on local conditions.
You aren’t likely to notice a reduction from 5% to 4.5% forams in the ocean as a marine biologist. It is more something you’d find out by doing a large-scale census of the entire ocean.