4 ms·

No idea about the credentials of that redditor... I'd love to have someone pick apart figure 1 and the data it claims to be based off: https://deliverypdf.ssr

by pygy_ 4y ago

No idea about the credentials of that redditor... I'd love to have someone pick apart figure 1 and the data it claims to be based off: https://deliverypdf.ssrn.com/delivery.php?ID=342110087101018118111081084101105006002092063023032070066031023098081090119103007117121123020058055102054117071081088003008121049055017040015002071098099113071096101033093000103076115096090076004076099086087105005024101124031001123019116072002113124121&EXT=pdf&INDEX=TRUE https://deliverypdf.ssrn.com/delivery.php?ID=342110087101018... The paper doesn't say that we've lost 90% of all phytoplancton BTW, it says that we're on track to have lost as much by 2045. the redditor also says that plankton level is rising in the arctic ocean, which isn't entirely surprising given that these very cold waters are now getting warmer. A massive drop everywhere else would still be catastrophic.

adrian_b 4y ago
Some parts of the paper seem OK, and there is indeed a high risk of disruption in the trophic chains of the ocean. Nevertheless there is one important claim of the paper that seems very wrong. While there is no doubt that the part of the plankton that uses either carbonates or sulfates as biominerals will be greatly affected, I am not aware of any reason why the diatoms and the other part of the plankton that uses amorphous silica as a biomineral would also be affected by water acidification. The paper claims that the diatoms and the silica-using living beings would also be affected, and their silica skeletons dissolved, but unlike salts, silica does not become more soluble in acid water. On the contrary, silica becomes more soluble in alkaline water. (That is why silica is classified as an acid oxide.) The diatoms could be affected by other kinds of water pollution, but they do not seem to be in direct danger from acidification, unless that would affect something else than their silica skeleton. In many places, the diatoms are the most important phototrophic component of the plankton, which consumes the carbon dioxide.
- pygy_ 4y ago
  I found this (https://phys.org/news/2022-05-diatoms-threat-decline-due-ocean.html https://phys.org/news/2022-05-diatoms-threat-decline-due-oce...), which is possibly concerning for diatoms: > As a result of ocean acidification, the silicon shells of diatoms dissolve more slowly. This is not an advantage—it causes diatoms to sink into deeper water layers, before they chemically dissolve and are converted back into silica. Consequently, this nutrient is more efficiently exported to the deep ocean and thus becomes scarcer in the light-flooded surface layer, where it is needed to form new shells. This causes a decline in diatoms, according to the scientists in their recent publication. The paper predicts a modest 13–26% decline by 2200 https://www.nature.com/articles/s41586-022-04687-0 https://www.nature.com/articles/s41586-022-04687-0
  - adrian_b 4y ago
    Yes, this is the right explanation. Because acidification has an opposite effect on silica shells in comparison with aragonite or calcite shells, which prevents the efficient recycling of the dead diatoms, the global effect will be a decrease in the concentration of silicic acid in sea water, which will diminish the abundance of diatoms and of other living beings that need silica.

by pygy_ 4y ago

adrian_b 4y ago

Some parts of the paper seem OK, and there is indeed a high risk of disruption in the trophic chains of the ocean. Nevertheless there is one important claim of the paper that seems very wrong. While there is no doubt that the part of the plankton that uses either carbonates or sulfates as biominerals will be greatly affected, I am not aware of any reason why the diatoms and the other part of the plankton that uses amorphous silica as a biomineral would also be affected by water acidification. The paper claims that the diatoms and the silica-using living beings would also be affected, and their silica skeletons dissolved, but unlike salts, silica does not become more soluble in acid water. On the contrary, silica becomes more soluble in alkaline water. (That is why silica is classified as an acid oxide.) The diatoms could be affected by other kinds of water pollution, but they do not seem to be in direct danger from acidification, unless that would affect something else than their silica skeleton. In many places, the diatoms are the most important phototrophic component of the plankton, which consumes the carbon dioxide.

pygy_ 4y ago
I found this (https://phys.org/news/2022-05-diatoms-threat-decline-due-ocean.html https://phys.org/news/2022-05-diatoms-threat-decline-due-oce...), which is possibly concerning for diatoms: > As a result of ocean acidification, the silicon shells of diatoms dissolve more slowly. This is not an advantage—it causes diatoms to sink into deeper water layers, before they chemically dissolve and are converted back into silica. Consequently, this nutrient is more efficiently exported to the deep ocean and thus becomes scarcer in the light-flooded surface layer, where it is needed to form new shells. This causes a decline in diatoms, according to the scientists in their recent publication. The paper predicts a modest 13–26% decline by 2200 https://www.nature.com/articles/s41586-022-04687-0 https://www.nature.com/articles/s41586-022-04687-0
- adrian_b 4y ago
  Yes, this is the right explanation. Because acidification has an opposite effect on silica shells in comparison with aragonite or calcite shells, which prevents the efficient recycling of the dead diatoms, the global effect will be a decrease in the concentration of silicic acid in sea water, which will diminish the abundance of diatoms and of other living beings that need silica.