Coral Reefs Why are coral reefs only found in clear shallow water? The zooxanthellae they have in their tissues require light for photosynthesis
Corals Phylum _________ Class ___________ Polyp stage only; no medusa stage Sexual and asexual reproduction Planula larva Cnidaria Anthozoa
____________ in Soft Coral Dinoflagellates live in the endoderm of hermatypic corals. These contribute to their hosts nutrition and metabolism. Without these symbiotes the corals cannot grow fast enough to build reefs. This limits reefs to shallow water. Zooxanthellae
What is Coral Bleaching? Long term exposure to high temperatures stimulates bleaching El Nino conditions stimulate bleaching When corals expel their zooxanthellae
Fringing Reef Barrier Reef Atoll
Structure of a Fringing Reef Reef flat2. Reef crest 3. Reef slope What part of the reef has the densest cover and the highest species diversity? The reef slope
Structure of a Fringing Reef What part of the reef has the most stressful conditions for organisms that inhabit it? The reef flat
What fish is this? Graze on seaweeds inside territories Gardeners: weed out unpalatable algae Algal growth thicker within territories than outside High density of cyanobacteria and other nitrogen fixers inside territory Damselfish
What fish is this? Teeth form parrot-like beak to nibble on hard corals. They grind the corals exoskeleton to get to the algae within the coral and defecate sand. Can defecate 5 tons of sand per year. Parrotfish
Anemone Fish with Host Anemone What fish is this?
Cleaners: Wrasses and Gobies Cleaner Wrasse Some wrasses set up cleaning stations along the reef. When a larger fish aligns itself at one of these cleaning stations, a cleaner wrasse removes the parasites from the fish
Threats to Coral Reefs Human expansion and development DeforestationErosionSiltation Sewage treatment facilities Eutrophication Over fishing Pollution Tourist Gift Trade Aquarium Trade – Cyanide; Explosives