Coral Reef Sara Hopkins and Danielle Johnson
FOUR TYPES OF CORAL REEFS • Patch ReefThese outcrops of coral usually lie within a lagoon • AtollThese circular or horseshoe-shaped reefs encircle a lagoon. No apparent landmass is normally associated with an atoll • Barrier ReefThis type of reef resembles a fringing reef, but they are located further from the shore and can be much bigger than fringing reefs. For example, the Great Barrier Reef in Australia lies 300 – 1000m (328 - 1093 yards) from shore, and 2000km (1243 miles) long • Fringing Reef This is the most common type of reef. They are located very close to land, and often form a shallow lagoon between the beach and the main body of the reef.
Reef Development Salinity • Corals require salinities between 30 and 40 parts per thousand Sedimentation • Excessive sedimentation reduces available light for coral growth Temperature • Optimal temperature for coral growth is 73-77°F (23-25°C) Light • Light levels are critical in maintaining the coral-algal symbiotic association
WHAT LIVES ON CORAL REEFS • Coral reefs are home to an abundant variety of living creatures fish, turtles, sharks, eels, crabs, shrimps, urchins, sponges, and algae.
Human impact on coral reefs • Chemical Pollution • Nutrients Loading/Sewage • Overfishing • Destructive fishing and boating practices • Construction and Sedimentation • Mangrove cutting • Rubbish/Litter • Tourists • Fish-feeding
Animals and adaptation • bluespine unicornfish (tatagaʻ). As their name suggests, these fish have a horn on their heads and sharp blue spines at the base of their tails. They use these spines to defend themselves against predators. • During the day, saddle wrasse hunt the reef for crustaceans, mollusks, and urchins to eat. At night, they hide in reef crevices to sleep. Saddle wrasse are endemic to Hawaii, meaning they are found nowhere else in the world. • Clownfish and anemones have a symbiotic relationship, where each organism receives benefits just by living together. Sea anemones are not mobile, they wait for their prey to swim by. they capture small shrimp and fish with the poisonous barb in their tentacles. Their poison is harmful or deadly to almost all fish and shrimp. This poison protects them from many predators.
Plants adaptation • Seagrass has adapted to living in habitats behind the coral reefs where they trap sediments from overloading coral reefs. Seagrass provides transferable food and oxygen to the coral reefs. • Mangroves have adapted by growing behind the beds of seagrass and coral reefs. Mangroves line shores and grow above sea water while their roots trap and prevent heavier sediments from overpowering the seagrass and coral reefs. Mangroves also provide a nourishing habitat for marine life. • Algae has adapted to survival on the coral reef by living inside the polyps of the coral. The algae provides the coral with nourishment and oxygen. In exchange, the coral provides a home for the algae.
Climate and location • Coral reefs are found in warm, tropical ocean waters (68 to 82 degrees Fahrenheit is required for reef survival). Since ample sunlight is required for warmth, coral reefs are typically found in the shallower ocean waters closer to shore
sources http://www.stanford.edu/group/microdocs/typesofreefs .html http://www.teachoceanscience.net/teaching_resources/education_modules/coral_reefs_and_climate_change/what_lives_on_a_coral_reef/ http://mesfiji.org/resources/environment/threats-to-coral-reefs-human-impacts http://www.ehow.com/facts_6173664_plants-adapted-coral-reef-survive_.html#ixzz2uLhLt55b