Coral Reef Gardeners
Coral reefs are the rainforests of the sea; forming some of the most diverse ecosystems on Earth. Though they occupy less than 0.1% of the world’s ocean surface, coral reefs are home to 25% of all marine species. Coral is one of the most important keystone species on the planet.
Paradoxically, coral reefs flourish even when surrounded by otherwise nutrient-poor water. They can do so because of their little friends. Coral have beneficial viruses, bacteria, algae, and fungi as microbial symbionts (microbiome).
Colorful damselfish live in tropical coral reefs. They eat small crustaceans, plankton, and algae. But not just any algae. Damselfish lack the digestive enzymes to consume many kinds of algae. But red alga is scrumptious. So damselfish cultivate gardens of red alga on the reefs. They pluck unwanted algae varieties from their territories and dispose of them at a distance. They weed out invasive plants. They chase away troublesome invaders, such as sea urchins, which would trample their fields. Protected red alga turfs thrive, affording damselfish abundant dining on one of their favorite foods.