You are by far one of my favorite people that post on here. You always cite your sources and post in a "toned down" format so even average readers know what you are saying and communicating.

This part was my favorite of the post:

The effects of ocean acidification are drastic. Many animals in the ocean- molluscs, corals, and more- all create hard shells for themselves. The most common material used is calcium carbonate. As the ocean gets more acidic, however, the carbonic acid deposited by rain reduces the available carbonate, making it harder and harder for the young of these species to get their shells started- and those that do get shells started often have thin, weak shells that provide little to no protection. Many of these shells and corals are even starting to see some minor erosion by acidity levels. Given that many of these shelled species are low on the food chain, this poses huge risks to oceanic ecosystems.

CaCO3 shells have shown erosion like you said, but there's also been findings of their organisms that use calcium carbonate shells creating stronger shells and even coatings over said shells. If they could keep this up or even up the rate at which they create these new shells, this would help save a lot of species. I would post a link to this but I do not have one at the moment, I remember reading this in an article one of my professors posted.

Edit: THIS is similar to what I was referring to, but not with CaCO3 shells. I talked to my professor and it's ongoing research by one of his graduate students that showed the CaCO3 shells doing similar things to the aforementioned post.