The Great Barrier Reef

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1 The Great Barrier Reef WHAT ARE CORAL REEFS? Coral reefs are among the world s most biologically diverse ecosystems. They are also one of the most endangered. Coral reefs are made of corals, which are large groups of small animals called polyps. The polyps live in a calcium carbonate skeleton. They have an opening in their center that has tentacles, which they use to feed on phytoplankton in the water around them 1. Coral reefs are generally found in clear, tropical waters, and they usually are found from the water s surface to about 150 feet deep, because they need sunlight for survival. Coral reefs house approximately 25% of the life in the ocean, yet they only make up about 1% of the ocean floor 2. THREE TYPES OF CORAL REEFS There are three types of coral reefs: fringing reefs, atolls, and barrier reefs. Fringing reefs line the shoreline of land masses, and they are most commonly found in areas like Hawaii and the Caribbean. Atolls are a series of low coral islands surrounding a central lagoon, and are most commonly found in areas like the Indo-Pacific. Lastly, barrier reefs are found farther from the shoreline in areas like the Indo-Pacific and the Caribbean 3. They are usually separated from land by a lagoon, and sometimes, they grow parallel to the coast 4. THE GREAT BARRIER REEF The Great Barrier Reef is one of the most magnificent wonders of the natural world, with its distinctive colors and beautiful wildlife, combined with its vast array of marine animals. It is home to more than 1,500 species of fish, 4,000 types of mollusks, and more than 200 species of birdlife 5. It started forming over 5 million years ago 6. It is more than 260 kilometers from the coast of Australia at its most distant point. Aside from its physical attraction, the Great Barrier Reef also acts as a wave buffer for Australia, preventing erosion, property damage, and even death 7. The Great Barrier Reef is sensitive to climate change, changes in wave and current movement, and physical damage. Events such as El Nino, the building of breakwaters, and runoff from the land can have negative effects of the Reef system 8. The Great Barrier Reef is home to thousands of species, such as sea urchins, sponges, sea stars, shrimp, lobster, crabs, fish, sharks, dolphins, whales, octopuses, snails, and many more. It is also home to many species of bird, who feed on the plant and animal life in the reefs. The largest reef in the world is the Great Barrier Reef off the coast of Australia, which is over 1,200 miles long ( Coral Reefs Biome ). It is not a continuous reef, and it contains over 2,800 individual reefs, of which 760 are fringing reefs ( World Heritage ).

2 FISH OF THE REEF There are over 1,500 species of fish in the Great Barrier Reef. Some examples are clown fish, butterfly fish, parrotfish, snappers, cod, grouper, eels, and many more. The overall structure of fish is streamlined, and fish vary greatly in size, shape, and color. The color patterns on the fish act as a warning to predators that they may be poisonous, or it can camouflage them so they can better hide from their predators and their prey. The smallest fish of the Reef is the goby, which is one centimeter long and weighs less than a gram, and the largest fish of the Reef is the giant cod and grouper that can weigh almost 4,000 kilograms. Most of the fish on the Reef range in size from 1 centimeter to 3 meters. These fish feed on what is most available, ranging from algae to other fish. They also eat plankton. Fish are free-swimmers, and use their fins to maneuver through the ocean water. The life span of fish in the reef is hard to determine, especially for the smaller, preyed on fish. If a fish can survive being eaten, it can live for quite a while. and generally glide along the bottom looking for food. They eat mollusks and crustaceans in the sand. They have moveable eyes, and their mouth is located on their underside. They use electro-receptors to locate their prey. Rays also have flat plates in their jaws, which they use to crush the shells of their prey before they eat them. They are also camouflaged to help prevent predation. //zettesworld.com/hdz04b/images/fish/cownos eray54101.jpg&imgrefurl= m/hdz04b/fish2.htm&h=432&w=576&sz=51&tb nid=oabx4mnkq90pvm:&tbnh=99&tbnw=132& hl=en&start=32&prev=/images%3fq%3drays%2 Bfish%26start%3D20%26svnum%3D10%26hl%3 Den%26lr%3D%26sa%3DN CRUSTACEANS There are a variety of crustaceans in the Great Barrier Reef. These include shrimp, lobsters, crabs, and mollusks. They range in size from 1 centimeter to 50 centimeters. fish.jpg SHARKS AND RAYS Sharks and rays are very closely related. Sharks and rays can range in size from 10 centimeters to 13 meters. There are about 350 species of sharks and 425 species of rays worldwide. They are both freeswimmers, with sharks using their fish to move through the water. Sharks have streamlined bodies, which help them move fast and turn quickly. Scientific investigations have showed that sharks have denticles, which help them move through the water faster by reducing drag from the water around them. They are also counter-shaded for camouflage. Most sharks are predators, feeding at dusk or after dark, and they use their rows of razor-sharp teeth to kill their prey. They feed on fish, squid, sea urchins, crustaceans, and even other sharks. Rays, on the other hand, are shaped like flattened disks with a long tail. They are also free-swimmers, Shrimp They are among the most diverse and active animals on the Great Barrier Reef. They are free-swimming, and they sometimes burrow in the sand to hide from predators. They have claws that help them catch their prey. They eat other crustaceans, small fish, and some feed on plants. Crabs & Lobsters Lobsters are the most commonly encountered species on the Reef. They have large, developed claws that inflict pain on their prey and on humans. They feed on other crustaceans, fish, and plants. They vary in size. Crabs also vary in size, shape, and color. They have tentacles that help them find their way around the ocean. They live in their shells, under the water and on land. They are scavengers, and feed on dead or decaying things. They usually walk sideways, but some swim. The decorator crabs specialize in camouflage, sticking bits of sponge, algae, and other bits and pieces onto their body. They are hard to see, unless they move.

3 Mollusks The Great Barrier Reef is home to between 5,000-8,000 mollusks. Mollusks are soft-bodied animals that have a hard shell for protection. They vary incredibly in terms of shapes and forms, but they all have a general structure: a head, and a body supported on a single muscular foot that helps them move through the water. Some mollusks do not have shells. Examples are octopuses, squid, and sea slugs. Because these do not have a shell, they defend themselves from predators by being brightly colored or very unpleasant tasting. Some even spray ink or a jet of water. pores that trap food particles carried by the passing water. They range from microscopic to 1 meter in size. They come in many different shapes and colors. They have an amazingly developed array of chemical toxins that ward off predators. They usually attach themselves to rocks, hard-shelled animals, or seaweed. They can repair and regenerate very easily. They are also very helpful in the process of building up coral reefs, because they bore into rocks, shells, or corals and help in bio-erosion. nimalpics/crusteacean1.jpg SEA CUCUMBERS There are approximately 1,150 species of sea cucumbers worldwide. They range in size from 1 centimeter to 60 centimeters. They are shaped like a big sausage. They do not really have a shell, but they have protuberances that act as body armor for protection. Some species are camouflaged to look like rocks on the seafloor. They have tentacles that they use to mop up particles for food. They spend their time lying on the seafloor or burrowing in the sand. They are immobile until the sun sets. Sea cucumbers eat tiny scrap particles, wiping their tentacles over the sediments on the seafloor to get food. As a defense mechanism, sea cucumbers can throw up their entire digestive system! This distracts their predators, which usually goes for their regurgitated food instead of them. It then takes the sea cucumber a couple months to grow its digestive tract back in its entirety. SPONGES There are approximately 1,500 species of sponges in the Great Barrier Reef. They are bottom-dwellers. They are loose colonies of cells, with an outer wall of Dimages/Sponges.png WHALES Whales are warm-blooded mammals. They have streamlined bodies and compact flippers that help with balance, steering, and movement through the water. Whales can reach up about 15 meters in length. They are divided into two groups: those with teeth (called toothed whales) and those without teeth. There are also the baleen whales, which use baleen plates to get their prey from the sea. Baleen whales eat krill, plankton, and small fish. Examples are the blue whale, humpback whales, and right whales. Toothed whales, such as the sperm whale and killer whale, eat sharks, seals, dolphins, birds, squid, and fish. Whales breathe through their lungs, and therefore, surface regularly to breathe. They also produce high-pitched sounds for communication purposes. Humpback whales produce songs that can last for hours. ceans/killer%20whales%202.jpg

4 AUSTRALIAN PELICANS Pelicans are very large birds, and the Australian Pelican is the largest of the seven species of Pelicans. They are characterized by long bills and a massive throat pouch. Their bills are usually centimeters long. The Australian Pelican also has the largest beak of any bird in the world. They weigh anywhere from kilograms and are meters long. They have massive wings, with a wingspan of meters. Fish are the main part of the Pelican s diet, but they also eat crustaceans, tadpoles, and turtles. They do hold food in their beaks, but only for a short period of time. Impressively, they can live between years or more 9 10! mals/pelicanau.jpg WATER PROPERTIES IN THE GREAT BARRIER REEF Coral reefs need water between degrees Fahrenheit, which is often located along the eastern shores of land. They usually develop in areas with a lot of wave action, because the waves bring in food, nutrients, and oxygen. They also prevent sediment from falling on the reef. Reefs need calcium to grow, which is usually more readily available in warm, tropical waters 11. Reefs usually have nitrogen and phosphorus of some form in their waters. Production of the Great Barrier Reef is partially controlled by dissolved inorganic nutrients, like nitrogen and phosphorus, which are taken up by the phytoplankton in the Reef and converted into organic matter 12. The water of the Great Barrier Reef is very warm, with much available sunlight, and the water is generally very salty and low in nutrients. The Great Barrier Reef has a tropical climate. The area is characterized by strong tidal currents, which are usually semi-diurnal with diurnal inequality towards the north. The maximum tidal range is about 3 meters by the coast, and increases from the coast to about 6-9 meters farther out. The water is vertically mixed for most of the year, but is affected by stratification due to freshwater input during January to April 13. The waves bring in and deposit sediments on the ocean floor, such as rocks and sand. The rocks and sand are home to many organisms in the reef, such as sponges and crustaceans that burrow in the sand. Coral reefs are being destroyed at an alarming rate. It is estimated that 10% of the world s coral reefs have already been destroyed. This destruction is due in large part to humans. Things like pollution, sewage, irresponsible fishing, poor tourism practices, erosion, and global warming damage these beautiful habitats ( Coral Reef Biome ). The Great Barrier Reef is endangered, as well, and needs to be protected, along with all the world s beautiful coral reefs. d_deck_large.jpg

5 1 "Why Care About Coral Reefs?" U.S. Coral Reef Task Force. 13 Apr < 2 "Coral Reefs Biome." 12 Apr < 3 "Coral Reefs Biome." 12 Apr < 4 Categories and Structure of Coral Reefs. University of Virginia Islands. 12 Apr < 5 "Great Barrier Reef." Culture and Recreation Portal. 13 Apr < 6 "Corals>Ecology." World Wildlife Fund. 12 Apr < 7 "Coral Reefs." Congressional Digest 82.7 (2003): Apr < 8 "Great Barrier Reef." Culture and Recreation Portal. 13 Apr < Text Box: "Coral Reefs Biome." 12 Apr < "World Heritage: Great Barrier Reef." World Heritage. 5 Feb Department of the Environment and Heritage. 13 Apr < 9 "ReefED-Animals." GBR Explorer Great Barrier Reef Marine Park Authority. 13 Apr < 10 "Who's Who." Reef Education Network The University of Queensland. 12 Apr < Text Box: "Coral Reefs Biome." 12 Apr < 11 "Coral Reefs Biome." 12 Apr < 12 "Environmental Status: Water Quality." Great Barrier Reef Marine Park Authority. 13 Apr < 13 Protected Areas Programme." 5 Jan UNEP World Conservation Monitoring Centre. 13 Apr <