How can replanting corals, instead of trees, remove CO2 from our atmosphere?

Who knew corals can reduce atmospheric CO2! After all, they don't have leaves, or live on land, so how can they pull CO2 from the air?

Much of the CO2 dissolved in the ocean came originally FROM Earth's atmosphere. Through simple diffusion, a higher concentration in the air resulted in CO2 moving into the ocean water. In fact, it's estimated that 26 percent of all the carbon released as CO2 from burning fossil fuels was absorbed by the oceans.

CO2 dissolved in ocean water is constantly equilibrating with atmospheric CO2, so any CO2 removed from seawater also reduces the amount in the atmosphere.

So how can corals possibly remove CO2?