Photoplankton and Oxygen levels

[Guinnessman1974]

I recently read that ocean photoplankton produces around half of the Oxygen in the Earth's atmosphere. So, if photoplankton is down by about 40% since 1950 then are O2 levels changing? Or is more O2 coming from elsewhere (Gaia!)?

[STYRBJORN]

As the total amount of O2 on the atmosphere makes a substantial buffer, the drop will take time to show up. Since we are systematically destroying the other main supplier, rain forests, it could turn out to be another tipping point.

[bigdave60dog]

I,left school in 1960. At the time I seem to remember that figure was closer to 70%. A big drop indeed.
It is fact that Global Climate Change id changing the sea approximately three times as quickly as the land mass is changing
Dvae

[Paul mabbott]

Originally Posted by STYRBJORN

..... . Since we are systematically destroying the other main supplier, rain forests, it could turn out to be another tipping point.

Not an excuse for destroying rainforests but boreal forests are probably the largest terrestrial carbon sink. We also shouldn't forget the great significance of bogs of all kinds.

[STYRBJORN]

Originally Posted by Paul mabbott

Not an excuse for destroying rainforests but boreal forests are probably the largest terrestrial carbon sink. We also shouldn't forget the great significance of bogs of all kinds.

You're right, of course. I should have said AN other major source, not THE other.

[animartco]

Originally Posted by STYRBJORN

As the total amount of O2 on the atmosphere makes a substantial buffer, the drop will take time to show up. Since we are systematically destroying the other main supplier, rain forests, it could turn out to be another tipping point.

I think any total decline in free oxygen should first show up in the sea? This is why I hope someone is seriously monitoring levels of oxygen in the depths of the ocean. The ocean has 'clines' at different depths of oxygen rich, and poor water, and the danger signal will be when the cline of oxygen poor water starts to rise. I probably haven't put this very well. Would someone like to explain it better? There is also a seasonal exchange of oxygen between the sea and the land.
What I am wondering is, are there clines in the upper atmosphere? Would it help to measure oxygen levels at a height?

[STYRBJORN]

This is not a dig at anybody, just me being precise/pedantic/pedagogic) (Delete as appropriate). We are discussing phytoplankton, microscopic plants, as against zooplankton, microscopic animals. Ain't no such critters as photoplankton.

Ric

[bigdave60dog]

Plankton levels are being closely monitored as oceanic gas levels.
I do not have the refs off hand but I keep seeing reports and programmes that suggest that this is happening.
Climate change is affecting the oceans at a rate approximately 3 times that of land. On "The Islands" we are acutely aware of this as these changes drastically affect our way of life. Eg the collapse of Phytoplankton causing a collapse of one particular species of Zooplankton causing a collapse in the Sand eel population affecting fish stocks negatively affecting our economy negatively, causing unemployment, alcoholism to increase.
This stuff is not academic to us it`s real and here now.
Dave

[STYRBJORN]

Originally Posted by bigdave60dog

Dave - I had no intention of implying that there is anything academic about about this issue. If I gave you that impression I apologise.

Ric

[Dorts]

No mention yet of Cyanobacteria, (Blue-green algae), which of course historicaly were the sole-producers of oxygen on earth and today still are a major factor in the production of our oxygen. I'm not sure we can talk of Photoplankton in isolation?
Dorts.