1. Coral Reefs

2. What is a Coral Reef? CaCO 3 from living things Reef builders –Corals –Algae –Sponges –Bryozoans –Shells

3. Reef Corals (Hermatypic) Anthozoans (no medusa stage) Scleractinian corals = “true” corals Zooxanthellae –Symbiotic dinoflagellates Photosynthesize Help deposit skeleton Most are colonies from founder polyp –Interconnected digestive and nervous systems

8. Coral Nutrition Zooxanthellae Predation on zooplankton Polyp tentacles Mucus Mesentarial filaments Zooxanthellae Predation on zooplankton Polyp tentacles Mucus Mesentarial filaments

9. Coral Reproduction Asexual Sexual Some internal Broadcast spawning Asexual Sexual Some internal Broadcast spawning

10. Corals in action!

11. Coral Restrictions Light for zooxanthellae (usually best in shallow, clear water) Warm water (but not too warm!!) - 68-86  F Substrate availability Salinity Sedimentation Pollution and eutrophication Light for zooxanthellae (usually best in shallow, clear water) Warm water (but not too warm!!) - 68-86  F Substrate availability Salinity Sedimentation Pollution and eutrophication

13. Coral Bleaching Normal Reef  Bleached 

15. Fringing Reefs Near shore - more vulnerable to? Reef flat Wide inner area Shallow - may be exposed Reef slope Steep outer area Much richer biologically Near shore - more vulnerable to? Reef flat Wide inner area Shallow - may be exposed Reef slope Steep outer area Much richer biologically

16. Fringing Reefs

18. Barrier Reefs Lagoon Separates reef from shore Usually soft-sediment with gentle water Reef flat May form sand cays (keys) Reef slopes Back slope and fore slope Lagoon Separates reef from shore Usually soft-sediment with gentle water Reef flat May form sand cays (keys) Reef slopes Back slope and fore slope

19. Barrier Reefs

21. Atolls Ring of reef surrounding central lagoon Indo-West Pacific Ring of reef surrounding central lagoon Indo-West Pacific

26. Reef Ecology

27. Nutrient Cycling Symbiotic algae Zooxanthellae Also in sponges, giant clams, others Animal waste Nitrogen fixation (cyanobacteria, symbionts) Currents Symbiotic algae Zooxanthellae Also in sponges, giant clams, others Animal waste Nitrogen fixation (cyanobacteria, symbionts) Currents

28. Eating Coral??

33. Competition Sessile animals compete for space and light Methods: Rapid growth Overgrowth Attack (poisons, stinging, digestions) Sessile animals compete for space and light Methods: Rapid growth Overgrowth Attack (poisons, stinging, digestions)

34. Competition

35. What about fish? Pre-settlement hypothesis Species present are result of larvae settlement Competition unimportant Post-settlement hypothesis Diversity determined by available niches and competition Pre-settlement hypothesis Species present are result of larvae settlement Competition unimportant Post-settlement hypothesis Diversity determined by available niches and competition

36. Symbiosis What is symbiosis? Do they have to live together? Obligatory vs. facultative symbiosis Types of symbiosis Mutualism (+,+) Commensalism (+, 0) Parasitism (+, -) What is symbiosis? Do they have to live together? Obligatory vs. facultative symbiosis Types of symbiosis Mutualism (+,+) Commensalism (+, 0) Parasitism (+, -)

37. Mutualism: Anemonefishes Why aren’t they stung? Fish gain protection and place to brood eggs Fish drives away potential predators of anemone, may provide nutrients Why aren’t they stung? Fish gain protection and place to brood eggs Fish drives away potential predators of anemone, may provide nutrients

38. Mutualism: Cleaning