Background I: The Rainforest of the Sea

This website is dedicated to giving the reader a sense of how climate change will effect coral reef ecosystems. Before we try to understand why a warmer and more acidic ocean will harm the coral reefs, let's begin with a background. This tab will provide an overview of coral reef ecosystems, and the next will explore the anatomy of coral polyps (the key player) in depth. Let's dive in! Coral reefs are sometimes referred to as the "Rainforests of the Sea" due to the incredible array of biodiversity they host. What animals are foundation to the reef ecosystem?

The Coral Polyp , an animal in the phylum cnidaria (pronounced nigh-Dear-eeah), is the star of the show when it comes to building reefs (Brief note: while 'coral' and 'polyp' will be used interchangably, polyp could mean any sessile member of the cnidarians and a coral need not build reef) . The polyp builds reef through depositing a calcium carbonate shell (skeletal cup) that it may contract into and use for protection. The unsung heros in this production are the unicellular algae called zooxanthellae (of the genus Symbiodinium), which live in the tissue of the polyps. The polyps and zooxanthellae have a symbiotic relationship, where the zooxanthellae receive substrates (chemical ingredients) needed to photosynthesize from the polyps, and the polyps get oxygen, glucose, and other products of photosynthesis in return (NOAA). For more on the anatomy of the coral polyps - the key to understanding what makes them susceptible to climate change - click over to the next tab!

Coral Polyps (oceanworld.tamu.edu)

A Hawaiian Reef (NOAA)

In addition to coral, other plants and animals deposit calcium carbonate to build reef, one major contributor is the crustose coralline algae (CCA), which we will later discuss as a target of ocean acidification (Pacific Whale). Specifically, the results of an experiment conducted by Jokiel et. al suggest that CCA may initially be effected more adversely by ocean acidification than coral polyps. Further, Hawaii's reef system houses a wide array of sea creatures, such as sponges, sea anemones, worms, sea stars, sea urchins, sea cucumbers, crustaceans, all kinds of mollusks, and turtles just to name a few. At the top of food chain are small sharks, eels, rays, and skates (Sea World). One fish in particular that cannot go without mention is the Parrot Fish. The Parrot Fish is responsible for creating the sand in the white sandy beaches that so many enjoy in Hawaii. The Parrot Fish nibbles away on the coral's calcium carbonate shell to reach the algae within. One Parrot Fish alone may chisel 5 tons of sand a year! (Sea World) Any damage to the coral polyps and other reef building organisms may be considered damage to the entire ecosystem to which they provide a home. As you read on, please keep this in mind.

Bullet Head Parrot Fish (Uhu) at Hanauma Bay (www.hanauma-bay-hawaii.com)