Let’s dive into our first exploration of marine ecosystems! We’ll start with one of the most iconic and popular, as well as diverse, ecosystems in the ocean: coral reefs.

A coral reef is a system of colonial and clonal coral polyps that create a tough calcium carbonate (CaCO3) shell to protect themselves, creating an undersea forest that teems with life. From crustaceans to sharks, from octopi to clownfish, the gamut of wildlife found in the coral reefs is of such great diversity that they have often been called the ‘rainforests of the ocean’.

Coral reefs teem with color and life. It is not unusual to observe a coral reef system that runs from yellow to green to red to pink and back again. The organisms that exist therein are also wildly multicolored. Everyone remembers the famous clownfish, the ones that live in anemone! Blue tangs, parrotfish, mantis shrimp, reef sharks… the list seems endless.

These ecosystems are not only important as housing for thousands upon thousands of species of animals and plants in the ocean, but they also interact with other ecosystems in a very helpful way. Reefs incur constant wave action and absorb some of that disturbance, lessening the impact on ecosystems like seagrass beds and mangroves that would suffer more from waves crashing on the shore. It also serves as a fledging point for adult fish to lead a productive life while they get ready to mate and return to the seagrass beds and mangroves to produce offspring.

Human interaction with coral reefs is immense. About 30% of the world population depends on coral reefs for food, and they are a popular tourist attraction in many tropical countries. Sadly, these once-pristine ecosystems are at risk from rising ocean temperatures and ocean acidification: the latter may render corals unable to produce their CaCO3 shells to protect themselves, a development which would have dire consequence for the otherwise soft-bodied anthozoans who have no shortage of predators in a hostile sea.

What will become of coral reefs? Some say they’ll be gone by the end of the century. I think there’s still some time left to salvage them. Only some time though.