1. Sea Grass Communities Vegetated, sandy substrates Vegetated, sandy substrates Shallow, clear water Shallow, clear water Tropical and subtropical habitats Tropical and subtropical habitats Food webs often include large grazers Food webs often include large grazers –turtles –dugongs or manatees Coastal locations increase exposure to impacts from terrestrial land use Coastal locations increase exposure to impacts from terrestrial land use

2. Shark Bay, Australia Western Australia Western Australia Isolated Isolated World Heritage Area World Heritage Area Rare example of an “intact” seagrass ecosystem Rare example of an “intact” seagrass ecosystem

5. Shark Bay overview: beds and channels

6. Diverse algae

7. Anemone in seagrass

8. Mega Grazers

9. Mesograzers

10. Top Predator Tiger Shark

11. Predator effects

12. What regulates sea grass?

13. Contrast a Seagrass system near people e.g., southern Florida e.g., southern Florida Near extinction of Near extinction of –manatees –large sharks –sea turtles Addition of Addition of –coastal development –altered hydrology –increased nutrient input

14. Problems in Florida Bay seagrass

15. Changes in seagrass beds

16. Complexity in habitats: e.g., Big Pine Key

17. Complexity in distributions of organisms

18. Heterogeneous communities

19. Changes in local development

20. Regional Patterns: Sampling Levels

21. Fresh water & nutrient inputs increase chlorophyll concentrations in water

22. P or N nutrient limitation varies

23. Dry season patterns of chlorophyll

24. Wet season patterns of chlorophyll

25. Larry Brand 2000 http://www.reefrelief.org/main.html: An Evaluation of the Scientific Basis for "Restoring" Florida Bay by Increasing Freshwater Runoff from the Everglades An Evaluation of the Scientific Basis for "Restoring" Florida Bay by Increasing Freshwater Runoff from the Everglades “Taken together, these data suggest that nutrients from Everglades- agriculture runoff are being transported to not just Florida Bay, but also the Florida Keys and coral reefs, and contributing to their eutrophication.” “Taken together, these data suggest that nutrients from Everglades- agriculture runoff are being transported to not just Florida Bay, but also the Florida Keys and coral reefs, and contributing to their eutrophication.”