Coral Reefs

At their simplest form, most people understand coral reefs as large ocean organisms or colonies, consisting of many like animals.

Typically coral reefs get associated with shallow water environments along the world's coastlines.

While no part of the description is factually wrong, coral reef specialists tell us it is incomplete.

Corals, like most living things, come in a variety of shapes and inhabit a variety of ocean locations. Corals, we are told can have either soft or hard bodies, and they can live in both shallow and deep water environments.

Shallow water coral reefs such as the world's largest, Australia's Great Barrier Reef, and the close to home reefs off the coast of Florida, fall into the group of hard bodied, shallow water reefs.

Hard bodied corals, formally placed in the order Scleractinia, often receive nicknames for the appearance of their colonization efforts. Scuba divers, for example, come to know corals by names such as brain corals, table corals, tube corals and elkhorn corals.

Shallow water coral reefs also get identified as complex ecosystems that support a biologically diverse community, from the individual coral polyps of any particular part of the reef, to the fish and humans that rely on them for their survival.

Scientists and lay persons continue to express concern regarding the effects of a changing climate on the world's near shore reefs.

Ocean acidification, the process where the near shore environment becomes more acidic due to the ocean's absorption of increasing amounts of carbon dioxide, presents a life threatening challenge to coral reefs. The logic is simple, the calcium carbonate necessary for hard bodied corals to grow gets dissolved in the presence of increased ocean acidity, which in turn stunts coral growth. Increases in ocean acidity also creates pressure on standing corals.

A changing climate also contributes to changes in water temperatures, posing even more threats to coral reefs, whose organisms have evolved to live within specific temperature ranges.

The term coral bleaching describes situations where areas of coral reefs have been subjects to extended periods of temperature changes, where the warmer waters kill off some of their food sources called Zooxanthellae. Zooxanthellae also are credited with giving corals their colors, hence their disappearance causes the corals to turn white.

© 2011. Patricia A. Michaels