Typically, corals reproduce by releasing sperm and egg cells into the water. They do this at the same time, in a process called synchronous spawning, to maximize their chances of success. Basically, the more sperm and egg cells that are in the water at the same time, the higher the rate of fertilization.
With this in mind, corals have developed a keen sense of timing. Often, all of the coral in a reef will release their reproductive cells on the same day. Scientists do not know exactly how corals manage to time this so perfectly, but they believe it may involve water temperature, sunlight and moonlight.
Researchers now believe that climate change may be disrupting this process, and causing corals to release their sex cells at different times. This greatly reduces their chances of reproductive success.
Corals routinely face dangers from fishing, boating, tourism and other human activity. In light of this new research, we need to strengthen our efforts to protect coral reefs. They are a true treaure of this planet, and provide a habitat for a great number of amazing and unique species.