Corals are the New Cool
I was flipping through the channels the other day and fell upon an episode of SpongeBob SquarePants (actually, as a marine biologist, I get a kick out of SpongeBob and always stop to watch, especially when it's in Spanish!). Mr. Krabs' daughter, Pearl, was trying to explain to her father
"see, no one says 'cool' anymore. That's such an old person thing. Now we say 'coral', as in 'That nose job is so coral.' "
It made me so proud, not the nose job part, but because corals really are cool and I should know - it was my focus of study for 6 years in graduate school!
So for those of you out there who may not know what corals are or how they could possibly be cool, here is the breakdown:
Corals are Related to Sea Anemones and Jellyfish
What unifies each of these animal groups is the stinging cells they use to capture food. These cells, called nematocysts, eject a venom that paralyzes their food source, making them easier to hold and eat. Though the stinging cells of corals and sea anemones don't hurt as badly as those of other local jellyfish species, they work in the same way.
Corals Are not Just One CritterCorals are actually made up of hundreds to hundreds of thousands of individual coral polyps that look like tiny sea anemones.
Corals are Older Than YouA collection of coral polyps grows only about an inch a year to eventually form a coral colony. The oldest coral colony in south Florida is over 300 years old!
Corals are not RocksInstead, corals are both plant and animal. During the day, plant cells called zooxanthellae, that are housed inside the corals' polyps, provide the coral with oxygen, sugars, and amino acids through photosynthesis. At night, the nematocysts on the coral polyps' tentacles work to sting and capture anything from tiny free-swimming zooplankton to small fish.
Some Corals SwayThough hard corals that contribute to building vertical dimension on the reefs are stationary, soft corals like sea fans are anchored to the seafloor by a "holdfast" - similar to tree roots. As they grow, they orient themselves in the ideal position to take advantage of food sources that come in with the currents.
Corals Like it Hot, But not Too HotCorals are found in water temperatures ranging from 73 to 84 degrees Fahrenheit (23 - 29C). Coral color comes from zooxanthellae. When corals become physically stressed from extended periods of high temperatures, the polyps expel their algal cells and the colony turns white. We call this "coral bleaching". Since corals receive up to 90% of their energy from zooxanthellae, without this algae, the corals can eventually die.
Corals are CloseThere are 3 rows of coral reefs that extend from the Dry Tortugas in the Florida Keys, all the way up to Martin County. The inner reef is within 1/2 mile from shore. The middle reef is within 1 mile from shore and the outer reef within 1.5 miles from shore. Because these photosynthetic corals need sunlight to survive, they are found to ~230 feet in depth so most coral reefs off of Florida are accessible by SCUBA. As the only state in the continental United States to have coral reefs, we are lucky here in Miami to have the opportunity to see these dynamic ecosystems.
Corals Love a Good OrgyAbout 3/4 of coral species are broadcast spawners which means they release massive numbers of eggs and sperm into the water to fertilize and produce offspring. Amazingly, this massive spawning occurs as a synchronized event in which eggs and sperm are released on the same day at the same time, often only over a few nights in a single year. Environmental cues, such as water temperature, day length, and lunar cycles dictate when this massive orgy takes place.
Corals are Treasure Chests Waiting to be OpenedCoral reefs are so biologically rich and economically valuable, that destroying just 1/2 mile of reef means the loss of between $137,000 to $1,200,000 over a 25-year period. They provide food, jobs, income, medicine, and protection to billions of people worldwide. Not to mention, they support more fish species per unit area than any other marine environment.
To learn more about Florida's coral reefs and what you can do to make a difference in the health of the Florida reef tract, follow the Florida Department of Environmental Protection's Florida's Coral Program on Facebook. We encourage all towns in Miami, not just Midtown Miami, to support the local environment we enjoy daily. Look for you local Miami Beach clean-up or start one of your own. As always, email your questions to me, your resident marine biologist, Paola: email@example.com.
Now that you know about corals, welcome to the cool kids club!