Only in shallow oceans because the deep ocean is a heterotrophic system loaded with CO2. At pH of 8.3, HCO3 is the dominant inorganic form of C, and we know this is capable of forming the weak acid, H2CO3, that can break down CaCO3 in the deep ocean. So as CaCO3 particles are settling out, they break down by this reaction. The answer is probably not. The ocean cannot take up CO2 as fast as we are releasing it.
Coral reefs are one of the most spectacularly diverse ecosystems in the world.
If corals become stressed, they spit out the algal symbiont and die. This die-off process is called bleaching . Dead corals no longer provide suitable habitat for fish to find food, and ocean biodiversity declines. There are several causes of bleaching. One is pollution by humans, a second is rising temperature, and in a recent article in Science , it looks like rising CO2 may also lead to bleaching.