1. Coral Reef Ecosystems

2. Our classical view of any ecosystem Seen as systems which transform energy and process organic matter Primary producers Primary consumers Secondary consumers Detritus Detritivores

3. Seen as systems which transform energy and process organic matter Primary producers Primary consumers Secondary consumers Detritus Detritivores = pathway for material (or carbon)

4. Seen as systems which transform energy and process organic matter Primary producers Primary consumers Secondary consumers Detritus Detritivore s = pathway for material (or carbon) = pathway for energy Heat

5. Organic veneer of a reef

6. Net water flow C, N, P, O Lagrangian Control Volume Measuring Ecosystem Dynamics

7. Time 1 Time 2 Eularian control volume Measuring Ecosystem Dynamics

8. Useful measures of ecosystem ‘metabolism’ P g = gross primary productivity (gC/m 2 /day) P/R = community respiration ratio E = excess production (gC/m 2 /day)

9. OceanOuter reef slope Fore reef Reef crest Back reef Lagoo n Water column Pg.2-.8?2-7 2.6-27.01-2.9-12.9 E.01-.65?-1-5.1.3-1.5-8.7-7.3-1.3-1.4-.5-3.4 P/R.9-1.38?.5-5.51-4.7-3.2.1-1.4.7-1.4

10. OceanOuter reef slope Fore reef Reef crest Back reef Lagoo n Water column Pg.2-.8?2-7 2.6-27.01-2.9-12.9 E.01-.65?-1-5.1.3-1.5-8.7-7.3-1.3-1.4-.5-3.4 P/R.9-1.38?.5-5.51-4.7-3.2.1-1.4.7-1.4 Corals Macroalgae Algal turfs 0246810 Microalgae Macroalgae Seagrass 0246810

11. How do coral reefs differ from this model? 1. Fluxes– nutrient and otherwise 2. Scales 4. The “unknowns” 3. Fate of the carbon

12. Cycles – nutrient and otherwise The level of any nutrient depends partly on the flux between pools -depends on the type of reef Barrier reef Water movement Level of recycling

13. Cycles – nutrient and otherwise The level of any nutrient depends partly on the flux between pools -depends on the type of reef Barrier reefFringing reef Water movement Level of recycling

14. Cycles – nutrient and otherwise The level of any nutrient depends partly on the flux between pools -depends on the type of reef Barrier reefFringing reefAtoll Water movement Level of recycling

15. Cycles – nutrient and otherwise Barrier reefFringing reefAtoll Degree of system closure + (factors increasing) - (factors decreasing) Water residence time,Nutrient recycling,Internal fluxes,Infilling Exports,External connectedness,Boundary fluxes,N limitation

16. Scales -nutrient level -inputs from ocean -species composition -heterotroph/autotroph composition

17. Scales -nutrient level -inputs from ocean -species composition -heterotroph/autotroph composition

18. Fate of the carbon Primary producers Primary consumers Secondary consumers Detritus Detritivores CaCO 3

19. The Unknowns

20. Microbial community Detritus Dissolved organics

21. Water (& nutrient flux) within a reef The Unknowns

22. Water (& nutrient flux) within a reef The Unknowns ?