Corals cannot move around to find mates, but instead reproduce through a technique known as spawning. In coral spawning, all of the corals from one species will release their eggs and sperm into the water over about 15 minutes, which rise to the surface and fertilize. This event, which usually happens just once a year for most corals, is one of the most amazing and miraculous events in all of nature. Not only is it amazing that corals can all time this event without having a brain or any means of communication, this is also where the next generation of corals will come from. Each coral that settles successfully is called a coral recruit, and is a distinct individual genetically. These recruits replace any adults that die, and also help to keep corals adapting to changing conditions in the planet’s oceans.
In our Coral Spawning and Larval Rearing Project, we go out and observe this event, and then collect eggs and sperm to stock out culturing ponds with larvae. We then take care of the larvae for several years, until they are big enough to be transplanted to the natural reef or artificial reefs as part of our different restoration programs. Most coral restoration programs focus on the asexual reproduction (cloning) of corals, but we are working on methods to increase the availability or using coral spawning capture and rearing to restore damaged reef areas.
Did you know that Charles Darwin is actually attributed with being the world’s first coral restorationist? He discovered that a broken coral rolling around in the sand would usually die, but by securing that coral to a piece of bamboo driven into the sand it could be saved. In the 150 years since, coral restoration has not come that much further – the materials and techniques have evolved, but the concept is still mostly the same: securing broken pieces or corals so they can regrow.