Coral Reef Ecosystem

Karen Lowe Lincoln Elementary School 4th Grade June 3, 2008

Coral Reef Ecosystem Ecosystems are composed of all the living populations in an area along with the non-living parts of that environment. Within all ecosystems, there are various food chains. A food chain is a feeding sequence of one set of organisms. A food chain begins with a producer, an organism that makes its own food, and ends with a consumer, an organism that cannot make its own food, so it eats other organisms. A food chain that survives well in a coral reef ecosystem begins with valonia, which is eaten by the lettuce nudibranch, which is eaten by the coral beauty angelfish. The flow of energy is completed when the angelfish is decomposed by fungi. Coral Reefs Around the World Coral reefs are an aquatic environment found in the world’s clear, tropical waters. Coral reefs are formed by colonies of thousands of little animals called coral polyps. It is the live corals that bring the beautiful tan, orange, yellow, purple and green colors to the reefs. When the corals die, they leave behind their hard, limestone skeletons. As new polyps grow and attach themselves to the existing formation, the reef grows. Coral reefs are grouped into three main types. Fringing reefs go from the coast out to sea. Barrier reefs

follow the coast, but are separated by a channel of water. Atolls are rings of coral around islands that are usually formed by volcanoes found far out in the ocean. Organisms that live in the reefs thrive in the warm, salt water. The clear, often shallow water, allows the heat and sunshine through. Water temperatures usually range between 70º-85º F. The salt water helps the aquatic plants with photosynthesis and provides the calcium that coral polyps need to build their limestone skeletons. Various marine plants and animals make a home in the coral reef. Coral Reef Producer One food chain in the coral reef begins with valonia as producers. Valonia are a type of bubble algae. They are the largest single cell organisms, sometimes growing to over 1 inch in diameter. Valonia, which grow individually or in small groups, often look like smooth, green bubbles. These algae grow rapidly. In fact, when combined with a certain bacteria, valonia can become a pest that kills the coral. More valonia grow when the older algae release spores into the water, which turn into new plants. The valonia have adapted to survive in the coral reef ecosystem. Since there are no bugs, bees, etc. to pollinate this plant, the valonia have learned to pollinate themselves. As the producer in several food chains, the valonia are eaten by some crabs, tang fish, other algae and by lettuce nudibranches.

Coral Reef Herbivore Lettuce nudibranches are the herbivores in this coral reef food chain. They have an elongated oval shape and can grow up to three inches long. The lettuce nudibranch is a gastropod, which means it is snail-like. However, unlike the snail, the lettuce nudibranch does not have a shell. Ruffled side appendages in green, yellow or brown cover its back and give it the look of “lettuce.” The ruffled back increases its surface area. This adaptation makes it possible for the lettuce nudibranch to absorb more oxygen for respiration. Lettuce nudibranches have another adaptation for survival, also. They can use the chloroplasts they get by eating algae to perform their own photosynthesis for extra energy. The lettuce nudibranch eats valonia and other phytoplankton. In the coral reef food chain the lettuce nudibranch is eaten by sponges and other small fish. Coral Reef Omnivore Coral beauty angelfish are the omnivores in this food chain, which consumes the lettuce nudibranch. These beautiful fish, which grow to a maximum of four inches, have tall, narrow, compressed bodies and small mouths. They have dark blue heads and fins, but their sides are red, yellow and orange with dark blue

stripes. The coral beauty angelfish can be territorial, so they are usually found alone or in very small groups of three to seven fish. The angelfish uses the coral reef for food and shelter. One adaptation of the coral beauty angelfish is its bright color. The bright colors act as camouflage against the colorful reef to protect it from larger omnivores and carnivores. Although this coral reef food chain ends with the coral beauty angelfish, the flow of energy does not end there. The energy is returned to the environment by decomposers. Coral Reef Decomposer Fungi are one of the decomposers in the coral reef. Fungi are organisms that live by eating dead and decaying matter. They are good for the coral reef ecosystem. For example, by decomposing the coral beauty angelfish, they put

nutrients back into the water so the phytoplankton can thrive. Marine fungi also convert deadly ammonia into nitrates that can then be eaten by other organisms.

Some fungi, however, that survive in coral reefs are bad. These fungi eat coral, which can destroy the reefs. For any particular environment, some kinds of plants and animals survive well, some survive less well, and some cannot survive at all. The food chain composed of valonia, lettuce nudibranch and coral beauty angelfish survives well in the coral reef because of their adaptations.

Bibliogrphy All About Oceans and Seas. < http://www.enchantedlearning.com/subjects/ ocean/Coralreef.shtml> May 7, 2008. Coral Beauty Angelfish. May 31, 2008. Kalman, Bobbie and Langille, Jacqueline. What Are Food Chains and Webs?. New York: Crabtree Publishing Co., 1998. Lettuce Nudibranch (image) <www.saltwaterfish.com/site_11_03/product/info. php?products_id=312> May 15, 2008. Lettuce Nudibranch, <www.peteducation.com/article.cfm?cls=16&cat=1904 Articleid=2143> May 15, 2008. Marine Fungi (imag)e. May 31, 2008. NatureWorks. April 9, 2008. "Valonia." Wikipedia, The Free Encyclopedia.   May 11, 2008.