Decision support tools for managing coral reef systems at local to regional scales

1. Modelling and Decision Support Working Group Decision support tools for managing coral reef systems at local to regional scales Jess Melbourne-Thomas GEF International Waters Conference October 2009

2. Key challenges Coral reef systems around the globe are vastly different (e.g. Indo-Pacific reefs versus Caribbean reefs, offshore atolls versus coastal systems) how can we develop a generic model structure thatis capable of capturing these differences? Representing inter-reef connectivities is crucial to a regional-scale approach, but the type and quality of connectivity data available differs greatly between regions how can we design an approach to represent regional-scale connectivities that is flexible and portable?

3. Key challenges The dynamics of coral reefs and associated human systems are inextricably linked how can we couple biophysical and socioeconomic dynamics tocapture diverse indicators of reef state? In addressing these issues, we need to ensure that the models we develop are robust what processes can we use for training and testing the models?

4. Addressing the challenges 1. Assembling the pieces - developing a generic model framework 2. Testing the framework - Meso-American Reef system 3. Demonstrating portability - Philippines/South China Sea region 4. Coupling biophysical and socioeconomic dynamics - the Mexican Caribbean

5. Consumers Benthos grazed EAC small piscivores herbivores macroturf macroalgae spawning corals brooding corals large piscivores urchins Assembling the pieces 1. Local scale ecological model

6. Consumers Benthos grazed EAC small piscivores herbivores macroturf macroalgae larval transport for corals, fish and urchins spawning corals brooding corals large piscivores urchins Assembling the pieces 2. Connectivity via larval transport

7. Consumers Benthos grazed EAC small piscivores herbivores hurricanes macroturf macroalgae spawning corals brooding corals large piscivores urchins fishing coastal development Assembling the pieces 3. Human impacts and disturbances affect local and regional scale processes

8. Testing the frameworkThe Meso-American Reef system (MAR) 1. Can the model reproduce a healthy reef state in the absence of fishing and disturbance? 2. Does the model reproduce broad-scale dynamics over the past 30 years given a schedule of known disturbance events?

9. macroturf coral macroalgae timestep (years) Testing the framework 1. Can the model reproduce a healthy reef state in the absence of fishing and disturbance? Predicts community structure of a healthy reef system Stable trajectories in benthic dynamics over long time series

10. piscivores herbivores urchins timestep (years) Testing the framework 1. Can the model reproduce a healthy reef state in the absence of fishing and disturbance? Predicts community structure of a healthy reef system Stable trajectories in consumer dynamics over long time series

11. Testing the framework Emergent spatial variability driven by patterns of larval connectivity

12. 1 2 1 2 3 4 5 1 2 3 4 5 subregion subregion 3 4 5 Testing the framework Emergent spatial variability driven by patterns of larval connectivity Regional variation in the ratio of herbivores : piscivores Low fish recruitment to Chinchorro

13. Timeline for the MAR: 1980 – present 2007: Hurricane Dean [subregions 2 & 3] 2005: Hurricanes Wilma and Emily [subregion 1] 1 2002: Hurricane Isidore [subregion 1] 2001: Hurricane Iris [subregions 4 & 5] 2000: Hurricane Keith [subregion 4] 1998: Coral bleaching event [subregions 1, 2, 3 & 5], Hurricane Mitch [subregions 4 & 5] 2 1988: Hurricane Gilbert [subregion 1] present 3 1980 2000 1990 4 5 1980 – present: increasing fishing pressure (selective for large piscivores) [entire region] 1980 – present: increasing nutrient/sediment inputs from coastal development [entire region] 1983 – 1984: urchin mortality event [entire region] 1986 – 1990: decline in hard coral cover due to white banddisease and bleaching [subregion 4] 2. Does the model reproduce broad-scale dynamics for the MAR over the past 30 years given a schedule of known disturbance events?

14. coral algae = hurricane = bleaching/disease Testing the framework 2. Does the model reproduce broad-scale dynamics for the MAR over the past 30 years given a schedule of known disturbance events? Correspondence between model output and observations of reef condition Mexico Mexico Belize Belize Honduras Honduras

15. Testing the framework 2. Does the model reproduce broad-scale dynamics for the MAR over the past 30 years given a schedule of known disturbance events? Correspondence between model output and observations of reef condition herbivores piscivores urchins Mexico Mexico Belize Belize Honduras Honduras

16. South China Sea Kalayaan Islands Sulu Sea Demonstrating portability Philippines / South China Sea (SCS) region 500km

17. 1 5 2 3 4 1 2 3 4 5 Emergent variability

18. 2006: Typhoon Cimaron [subregion 1] Typhoons Xansane and Durian [subregion 2], COTS outbreak [subregions 1, 2 & 4] South China Sea 2004: Typhoon Nanmadol [subregion 1], COTS outbreak [subregion 3] 1999: Typhoon Dan [subregion 1] 1998: Bleaching event [entire region] 1 1995: Typhoon Angela [subregion 2] 1993: Typhoon Koryn [subregion 1] 1991: Mt. Pinatubo eruption [subregion 1] 1989: Typhoons Gordon and Angela [subregion 1] 2 1987: Typhoons Betty and Nina [subregion 2] 1983: Bleaching event [subregion 1] 1962: Typhoon Lucy [subregion 5] 3 present 1960 2000 1970 1980 5 4 1990 1986: muro-amibanned [entire region] 1990s: advent of pa-alingand decline in dynamite fishing [entire region] 1965 – 1990: increase in destructive fishing [subregions 1 – 4] 1990 – present: decrease in destructive fishing 1960 – present: increasing fishing pressure [entire region] 1960 – present: increasing nutrient/sediment inputs from land clearing [subregions 1 – 4] Timeline for the Philippines-SCS: 1960 – present

20. fish biomass (g/m2) herbivores, piscivores benthic cover (%) coral, algae (1) Reserve placement based on larval connectivity between subregions (2) Reserve placement based on larval connectivity within subregions Best recovery of fish biomass and coral cover (2) + additional management (reduced fishing pressure in northern subregions and gear restrictions) Scenarios for the Philippines: Marine Reserves

21. Synergistic effects of coral bleaching and nutrification + sedimentation on coral cover Scenarios for the Philippines: Coral Bleaching H = Healthy NS = Nutrification + Sedimentation BL10 = Coral bleaching once every 10 years BL5 = Coral bleaching once every 5 years

22. Dissemination

23. Dissemination Demonstrating the importance of managing water quality to build resilience

24. Predicting distributions of potential reef futures under alternative management approaches frequency of model outcomes indicator of reef state

25. Coupling biophysical and socioeconomic models for the Mexican Caribbean Socio-economic model (SimReef) lobsters Biophysical model

26. Coupling biophysical and socioeconomic models for the Mexican Caribbean Socio-economic model (SimReef) lobsters Biophysical model

27. coral and algal cover (%) fish and lobster catches (tonnes) bankruptcies (# boats) and profits (1000 US$) Coupling biophysical and socioeconomic models for the Mexican Caribbean:Preliminary Validation