MARINE ECOLOGY AT CALABASH CAYE

Every one must be struck with astonishment, when he first
beholds one of these vast rings of coral-rock, often many
leagues in diameter, here and there surmounted by a low
verdant island with dazzling white shores, bathed on the
outside by the foaming breakers of the ocean, and on the
inside surrounding a calm expanse of water, which, from
reflection, is of a bright put pale green color.

So wrote twenty-six-year old Charles Darwin upon returning from his circumnavigation of the globe aboard the HMS Beagle. Those of us who took marine ecology could understand why Darwin felt the urge to wax poetic on the topic of coral reefs. This semester we returned to Calabash Caye, a small island in Turneffe Atoll largely dominated by mangroves. During the first two days, inclement weather kept us mostly indoors, huddling over cups of coffee and ovaltine, while listening to professor Laurie Furlong classify groups of marine organisms from phylum to species. Thankfully, the sun made an appearance just as we were ready to hit the water for some serious snorkeling. A highlight for many students was the mangrove snorkel. To many tourists, mangroves are smelly and unsightly. But if only they could don a mask and snorkel, they would realize that a miniature coral reef, with all the colours of the rainbow, is growing right on the prop roots of the red mangrove! Indeed, mangroves play a vital role in the marine ecosystem. Not only do they provide a nursery for juvenile fish but they also prevent sediment from reaching, and choking, the corals. Another memorable experience was the night snorkel. It’s always a little unnerving jumping into water at night, not knowing what may be lurking below you, having learned in lecture that sharks can see you and smell you well before you can see them. Taking the plunge at night was well worth it, however, as we saw nocturnal creatures, like lobsters and squid. The week ended with a volleyball game where we were eaten up by sand flies…


Did you know? (From Osha Gray Davidson’s, The Enchanted Braid)

A bumper sticker for reef fish might read, “God Created Adam and Eve, Adam Who Became Eve, Eve Who Becomes Adam, and Adameve.” Most reef fish are hermaphrodites, meaning that they can change sex. The most common form of this behaviour is for females to change into males. Interesting…

Corals are classified as animals, not plants. Very counterintuitive. And they eat other beings! At night, their tentacles emerge to shoot paralyzing darts into their prey, mostly zooplankton, which they then pull into their primitive mouths.

The sand beaches that we all love are actually excrement from parrot fish, who crunch at the hard rock of the reef to get at the algae. Think about that the next time you’re soaking up the rays on your favourite beach…