[mkempe]

In actual fact and science, yes, emphatically yes. Reef-building corals contain photosynthetic algae; these zooxanthellae are an endosymbiont that depends on and consumes CO2 for the direct benefit of its host. [1]

Up to 90% of the organic material photosynthetically produced by the zooxanthellae is transferred to the host coral tissue. "This is the driving force behind the growth and productivity of coral reefs." [2]

The coral polyps thrive when they have access to nutrients produced by their symbiont algae. These algae thrive when they have access to CO2, H2O, and sunlight. Thus CO2 does turn into coral reefs.

[1] Coral-algae metabolism and diurnal changes in the CO2-carbonate system of bulk sea water (2014) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4034600/

[2] https://oceanservice.noaa.gov/education/tutorial_corals/cora...

[amvalo]

Ok, technically yes, but ocean acidity is a far bigger effect, and that's what the GP was confused about.

[mkempe]

Please stop moving goalposts, and quit denying scientific facts.

1. As described above, CO2 feeds symbiont algae and thereby drives the growth of coral reefs.

2. The algae and polyps have been shown to be constantly adapting to variations in local pH levels and water temperature. [1] As one would expect based on a) understanding the theory of evolution; b) observed "bleaching" and re-colonizations of corals for wider, mid- to long-term variations; and c) 20+ million years of corals thriving under a wide range of water temperatures, CO2 levels, and pH levels.

[1] Active modulation of the calcifying fluid carbonate chemistry (δ11B, B/Ca) and seasonally invariant coral calcification at sub-tropical limits (2017) https://www.nature.com/articles/s41598-017-14066-9