ASL Coral Reefs for Kids

Coral Reefs. Coral reefs are ecosystems found in clear, shallow, tropical waters around the world. An ecosystem is an environment where plants and animals live and interact. Many types of marine animals and plants live in coral reefs. Coral reefs are among the world's oldest living ecosystems. Most of the coral reefs today were formed after the last ice age. The melting ice caused the sea levels to rise. The waters got high enough that they flooded the edges of some of our continents and islands and created these beautiful ecosystems near the beaches. Coral reefs are common in Hawaii and the Caribbean and as well as other islands. The wide variety of plant life and creatures in coral reefs make these islands popular places to visit. Coral are amazing and beautiful organisms. Did you know that coral can be white, red, pink, green, blue, orange, or purple? And did you also know that coral is actually an animal? Coral is a living organism related to jellyfish. Tiny individual animals called coral polyps make up coral reefs. These small animals have soft, tube-shaped bodies and a ring of tentacles surrounding their mouths. They also have hard exoskeletons, which are outer coverings that support the coral polyps. Unlike plants, coral does not make its own food. It eats small animals and plants called plankton and algae. Microscopic algae that lives in the tissues of coral polyps helps it to survive. Coral reefs are formed by a single coral polyp, which attaches itself to a rock or seabed. The coral polyp then builds an exoskeleton of limestone to protect itself. Eventually, these structures turn into huge reefs that form over thousands of years. The reefs built by coral polyps are usually found at depths of less than 150 feet, where the temperature is warmer. The water at these depths is usually clear, which allows the sunlight to move through it better. The reefs need calcium to grow, which is found in the warmer, shallow waters. Reefs also develop in areas where there is plenty of wave action. The waves bring in food, nutrients, and oxygen to the coral reef. The waves also wash away a residue from the coral. Coral reefs vary in shape, size, and color. Let's take a look at a few different types of reefs. Fringing reefs are the most common type of reef. They grow close to the shorelines of continents and islands. Fringing reefs can be attached to the shore or be separated from it by a narrow strip of water called a lagoon. The Ningaloo Reef is the biggest fringing reef in the world. It is located on the coast of Australia and is over 160 miles long. Barrier reefs are farther offshore and can be several miles from the shorelines of continents and islands. Unlike fringing reefs, barrier reefs have some deeper portions. The largest reef in the world is the Great Barrier Reef found in Australia. It is more than 1600 miles long. That's 10 times the length of the Ningaloo Reef. The Great Barrier Reef is so large, it can be seen from space. Atolls are rings of coral that encircle a body of water called a lagoon. They are found in the tropics and subtropics, which are warmer areas near the equator. Atolls usually begin as a fringe reef surrounding a volcanic island. As the coral expands and grows, the island sinks into the ocean, leaving the ring of coral. Some atolls, like the Marshall Islands, are so big people live on them. Other types of coral reefs include apron reefs. These reefs look like a fringing reef but are more sloped. Patch reefs are circular reefs that grow in between a fringe reef and a barrier reef. These reefs grow in water that is only about 10 to 20 feet deep. Ribbon reefs are long, narrow, winding reefs. Some ribbon reefs form the outer edges of the Great Barrier Reef. Each type of reef is an ecosystem. Various kinds of plants and animals inhabit coral reefs. Every coral reef eventually develops different zones. The three different zones are occupied by several kinds of corals, fish, plants, and ocean life depending on the location in the world. The shore or inner reef zone is found between the highest point of the reef and the shoreline. Depending on the shape of the reef, this area is full of life that includes fish, starfish, sea cucumbers, and anemones. The crest reef zone is the highest point of a reef, where waves break over it. The fore or outer reef zone is where the reef wall falls and the waters get calmer. This zone is around 30 feet deep. It is the most populated part of the reef with a variety of coral species. Even though coral reefs only make up about 1% of the ocean floor, they make up 25% of life in the ocean. Animals use the coral reefs as stopping points as they travel from place to place, kind of like hotels for sea creatures. Sea urchins, worms, sea stars, sponges, sharks, rays, lobster, octopus, and snails are a few of the abundant animals that live together among the coral. This is a word that describes how these animals live together. The word is symbiosis. Symbiosis means that the organisms relay on each other for their survival. One example of symbiosis is the anemone fish and the sea anemone. The sea anemone's tentacles provide protection for the fish and its eggs. In return, the fish protects the anemone from predators. Plants are also found in the coral reefs. Plant plankton called phytoplankton, algae, and other plants convert the light from the sun into energy to make its food. Algae and seagrasses are the main types of plants in the coral reef ecosystem. The plants provide food and oxygen to the animals that live on the coral reef. One of the most important plants in the reef are seagrasses. They provide shelter for young reef animals like conch and lobster. Coral reefs are much more important to Earth than many people realize. They protect the coastline from erosion, storms, floods, and damage caused by strong waves. Coral reefs are also important to people who have jobs as fishermen or to the tourist industry. Medical discoveries, such as medicines for cancer and arthritis, have also come from coral reefs. But even more importantly, reefs help remove and recycle carbon dioxide from the air, which contributes to global warming. Unfortunately, coral reefs are being destroyed faster than they can grow. Much of the damage is done by overfishing, pollution, and global warming. Coral bleaching is one of the problems global warming creates. It occurs when the temperature of the water becomes too warm or too cold. When this happens, corals release the algae that is living in their tissues. This causes the coral to turn white. The coral then becomes stressed and could die if the water temperatures don't return to normal. Tourism often leads to reef damage because visitors stand on them, touch them, or bump into them with their boats. Some scientists believe the Great Barrier Reef will not even be around in less than 30 years. If our reefs die, that also means that many plants and animals will die as well. Coral reefs are important ecosystems found all over the world. Coral reefs provide the habitat for many different types of marine animals and plants. Just like all ecosystems, coral reefs need to be protected. They are important to the survival of planet Earth. Hope you had fun learning with us. Visit us at learnbright.org for thousands of free resources and turnkey solutions for teachers and homeschoolers.