Coral reefs are the marine equivalent to rainforests on land. They only take up 1% of the ocean floor, but they are home to 25% of the marine species, including crustaceans, sea snakes, sea turtles, manatees, mollusks, sponges, echinoderms, like sea stars and urchins, and 4000 species of fish, which include sharks and rays. Coral reefs are colonies of polyps that feed on plankton. What makes these animals really unique is that they are actually the host home for zooxanthellae, which is a type of algae that actually gives the coral its vibrant colors. The polys and the algae have a beautiful symbiotic relationship. The algae need the C02 and waste products that the polyps produce for photosynthesis and in return the polyps receive oxygen and the organic products of photosynthesis, which they use to construct their limestone skeletons.
This relationship has been thriving for the past 500 million years, but in the past few decades has been facing some very troubling times. When the coral is unhappy due to stresses in its environment, it expels the algae. The result is coral bleaching, which is something that is being seen far more often and on greater scales in coral reefs around the world. If the conditions don’t become idea again in a relatively short period of time, the algae will not return and the corals will begin to starve, weaken structurally, and eventually die.
What stresses out a coral reef?
There are both natural and man-inflicted stresses that greatly impact the health of the coral reefs. Sadly, the man made stresses are more prevalent and tend to leave a longer-lasting impact on the coral reefs than hurricanes, El Nino, and natural-born diseases combined. These natural factors come and go and have been affecting the coral reefs since the beginning of their time. However, overfishing, destructive fishing practices like long lining and bottom dredging, coastal development, pollution, unsustainable and careless tourism practices, and global warming are the key killers.