2. The Coral Reef Ecosystem

3. Coral Polyps & Zooxanthellae Zooxanthellae are dinoflagellates that live symbiotically within the corals. Zooxanthellae are dinoflagellates that live symbiotically within the corals. Polyps get 40% of their nutrients from photosynthesis and 60% from filter feeding. Polyps get 40% of their nutrients from photosynthesis and 60% from filter feeding. Corals take in O 2 and give off CO 2 Corals take in O 2 and give off CO 2

4. Environmental Factors necessary for Reef Growth Temperature Temperature Never below 20 o C Never below 20 o C Light Light For photosynthesis For photosynthesis Salinity Salinity Optimal salinity is 35 g/L Optimal salinity is 35 g/L Wave Action Wave Action Carry food, nutrients and oxygen to the reef and distributes larva Carry food, nutrients and oxygen to the reef and distributes larva

5. Hard Corals: Hexacorallia

6. Stony Corals: 6-part symmetry, Stony Corals: 6-part symmetry, Solitary: live by themselves Solitary: live by themselves mushroom mushroom Colonial: live in groups Colonial: live in groups brain, staghorn (major reef-forming corals) brain, staghorn (major reef-forming corals)

7. Hexacorallia: Day & Night

8. Soft Corals: Octocorallia

9. Soft Corals: Octocorallia Soft corals: 8-part symmetry, skeletons of keratin and calcareous spicules. Soft corals: 8-part symmetry, skeletons of keratin and calcareous spicules. Sea Fans, Sea Whips, Sea Pens, and Sea Pansies Sea Fans, Sea Whips, Sea Pens, and Sea Pansies

10. Coral Reef Distribution

11. Coral Reef Distribution Found in all oceans Found in all oceans 20  N and S of the equator 20  N and S of the equator Indo-Pacific has 1/3 of the world’s coral reefs, and is the center of biodiversity for the reefs of the world. Indo-Pacific has 1/3 of the world’s coral reefs, and is the center of biodiversity for the reefs of the world.

12. Types of Reefs: Fringing Reef A reef that form borders along the shore; extensions of the coastline Common in the Florida Keys, the West Indies and Hawaii

13. Types of Reefs: Barrier Reef A reef far from shore and separated from the coast by a lagoon or channel; outermost part is a steep coral wall. Located at the Great Barrier Reef, the Caribbean, Tahiti, Indonesia, New Guinea and Belize

14. Types of Reefs: Atoll A circular chain of reefs that surround a lagoon A circular chain of reefs that surround a lagoon Bikini Atoll Bikini Atoll Common in the Indo-West Pacific Region Common in the Indo-West Pacific Region

15. Coral Reef Zones Lagoon: area between shore and reef Lagoon: area between shore and reef Reef Wall: deep water beyond the barrier reef Reef Wall: deep water beyond the barrier reef

16. Symbiosis on the Reef Mutualism: both partners benefit from the relationship. Mutualism: both partners benefit from the relationship. Cleaner wrasse/fish Cleaner wrasse/fish Zooxanthellae/coral Zooxanthellae/coral Clownfish/anemone Clownfish/anemone

17. Coral Reproduction Sexual: internal or external fertilization. Asexual: fragmentation, fission and budding.

18. Spawning releasing eggs and sperm into H20 Usually occurs during a full moon

19. Natural Threats to Reefs Hurricanes damage reefs due to excessive wave action. Crown-of-thorns sea star consumes 46-62 in 2 of coral/day. El Niño changes water temperature.

20. Human Caused Threats

21. Human Caused Threats Global warming and Greenhouse effect Global warming and Greenhouse effect Hot water from run-off Hot water from run-off Sediment Sediment Oil pollution Oil pollution Mining Mining Fishing line / plastic Fishing line / plastic Tourism – anchors, boats, propellers, divers Tourism – anchors, boats, propellers, divers Collecting – dynamite, cyanide, cameos Collecting – dynamite, cyanide, cameos

22. Coral Bleaching Results from the loss of symbiotic zooxanthellae. Results from the loss of symbiotic zooxanthellae. Has increased in both frequency and worldwide distribution over the last 20 years. Has increased in both frequency and worldwide distribution over the last 20 years. Causes: Causes: Temperature Temperature Solar irradiance Solar irradiance Sedimentation Sedimentation

23. Conservation Tips 1. Be aware of environmental issues and keep informed. 2. Take care of the environment: Leave life alone, know and follow fishing regulations, don’t buy products from endangered or threatened species or corals. 3. Dispose of hazardous materials properly: do not dump anything down the drain. 4. Recycle plastics, motor oil, bottles and other forms of trash. 5. Save energy and decrease the need for oil.