CORAL REEF (ONE SMALL SQUARE)

Coral Reef (One Small Square)



Coral Reef (One Small Square)

Without the benefit of scuba diving classes and a collection of rented equipment, most children will not grow to see the coral reefs of the world in person. Brought vividly to life in the imaginations of children through the major animated film Finding Nemo and the short, live action segments that make up “Come See the Sea” on children's television programming, the coral reefs of the world serve as a sticky point of interest to delve into the life cycles of the creatures who make this fascinating ecosystem their home.

Corals are composed of thin plates, or layers, of calcium carbonate secreted over time by hundreds of soft bodied animals called coral polyps. Polyps range in size from a pinhead to a foot in length. Each polyp lives in a symbiotic relationship with a host zooxanthellae that gives the coral its color. Zooxanthellae take in carbon dioxide, process it through photosynthesis, and give off oxygen and other important nutrients that are then used by the host polyp. As in all photosynthesizing organisms, this means that corals must be exposed to a sufficient amount of sunlight. This confines most corals to shallow waters that are clean and clear.

There are two kinds of corals: hard and soft. Hard corals (Scleractinia), such as brain, star, staghorn, elkhorn and pillar corals have rigid exoskeletons, or corallites, that protect their soft delicate bodies. Soft corals (Gorgonians), such as sea fans, sea whips, and sea rods, sway with the currents and lack an exoskeleton.

In Coral Reef - part of the One Small Square series for six to nine-year-old children, an in-depth, vividly illustrated journey travels through a small portion of the Great Barrier Reef off the coast of Australia. Focusing in on an three-dimensional section of reef measuring four feet to a side and extending down in a rectangular column roughly twice that in length, series author Donald M. Silver guides young readers through the intricacies of reef flora, fauna, reproduction, nocturnal creatures, inter-species cooperation and many other fascinating features of this vibrant ecosystem.

Coral reefs are one of the most biologically diverse ecosystems on earth, rivaled only by tropical rain forests. They are made up not only of hard and soft corals, but also sponges, crustaceans, mollusks, fish, sea turtles, sharks, dolphins and much more. Competition for resources such as food, space and sunlight are some of the primary factors in determining the abundances and diversity of organisms on a reef. Each component of a coral reef is dependent upon and interconnected with countless other plants, animals and organisms. This means that fluctuations in the abundance of one species can drastically alter both the diversity and abundances of others. While natural causes such as hurricanes and other large storm events can be the stimulus for such alterations, it is more commonly anthropological forces that effect these types of shifts in the ecosystem.

For example, overfishing of herbivorous fish often results in increased growth of algae and sea ...