Over billions of years, the ocean has removed "excess" CO2 from the ocean in the form of carbonates from accumulation of organic and inorganic precipitates that collect on the bottom of the ocean and accumulate in deposits up to miles thick. The typical cliff you see on your ride in the mountains is the tip of the ice berg of trillions of tons of CO2 that was removed previously by the ocean. They may be limestone (carbonates), reefs (largely calcite (carbonate), sandstones with carbonate cementing, or precipitated carbonates, etc. The anti-science clowns like to pretend to be informed and they want you to believe that somehow it is different this time. The "acidification" this time is bad because it is from humans and industry. Yes it may go up in acidity slightly, remaining well within the alkaline range, and it should increase precipitation of carbonates. Alarmists would like you to believe that increasing the concentration of carbon will reduce the precipitation of carbonates. It is an odd theory that I certainly never heard from a geologist.

Ocean acidification is the name given to the ongoing decrease in the pH of the Earth's oceans, caused by the uptake of carbon dioxide (CO2) from the atmosphere.[1] An estimated 30–40% of carbon dioxide released by humans into the atmosphere dissolves into oceans, rivers and lakes.To maintain chemical equilibrium, some of it reacts with the water to form carbonic acid. Some of these extra carbonic acid molecules react with a water molecule to give a bicarbonate ion and a hydronium ion, thus increasing ocean "acidity" (H+ ion concentration). Between 1751 and 1994 surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14,representing an increase of almost 30% in H+ ion concentration in the world's oceans.

We have been dumping excess CO2 into the atmosphere for years and carbon also travels via ground water and rivers into the oceans, all of which is why the acidity has gone up and will continue to go up

Same thing that has always happened in the past when CO2 is emitted from the oceans. When the world had 1000 part per million in the past and the globe was warm enough to have lush dense forests on Antarctica the oceans were healthy and teaming with life in direct contradiction to all the hysterical doom and gloom BS prophecies from the AGW fundamentalists.

I take it that you are asking what will happen to the pH levels of the oceans as they absorb more atmospheric CO2? Should this be the case then the result would be the acidification of the oceans. This does not mean that the oceans will become acidic. It means the pH levels of the oceans will become less alkaline.

Our oceans have a huge buffer of calcium, and all the CO2 in our atmosphere would not make a measurable difference.

I am always puzzled that people ask this question, if they asked what would happen to our lakes and rivers, that would be different.

Just like spitting in the ocean raises sea levels, a dash of CO2 in the oceans affects pH levels.

I won't worry about your spit flooding the Florida peninsula if you don't worry about my CO2 marinating all the fish in the sea.

nothing

pH is lowered, that is getting more acidic.