Grantee Research Project Results
2006 Progress Report: Connectivity in Marine Seascapes: Predicting Ecological and Socioeconomic Costs of Climate Change on Coral Reef Ecosystems
EPA Grant Number: R832223Title: Connectivity in Marine Seascapes: Predicting Ecological and Socioeconomic Costs of Climate Change on Coral Reef Ecosystems
Investigators: Sanchirico, James N. , Mumby, Peter J. , Hastings, Alan , Brumbaugh, Dan , Micheli, Fiorenza , Broad, Kenneth
Institution: Resources for the Future , American Museum of Natural History , University of California - Davis , University of Exeter , University of Miami , Stanford University
Current Institution: Resources for the Future , American Museum of Natural History , Stanford University , University of California - Davis , University of Exeter , University of Miami
EPA Project Officer: Packard, Benjamin H
Project Period: March 1, 2005 through February 28, 2008 (Extended to June 30, 2009)
Project Period Covered by this Report: March 1, 2006 through February 28, 2007
Project Amount: $749,087
RFA: Effects of Climate Change on Ecosystem Services Provided by Coral Reefs and Tidal Marshes (2004) RFA Text | Recipients Lists
Research Category: Aquatic Ecosystems , Water , Ecological Indicators/Assessment/Restoration , Climate Change , Watersheds
Objective:
Our project integrates theory and data from ecology, biology, and the social sciences to address major questions about the potential consequences of climate change (sea level rise, increases in sea level temperatures, and increased storm intensity) on coral reef-mangrove ecosystems. Using a structure that is representative of Caribbean ecosystems, we systematically explore several core questions, including: (a) How do local impacts, including overfishing and mangrove deforestation, affect the vulnerability of Caribbean coral reefs to climate change? (b) When do socioeconomic responses to changes in the ecosystem triggered by climate change stressors exacerbate the vulnerability of coral-reef ecosystems to future stressors? (c) What are the critical ecological and/or socioeconomic uncertainties for predicting climate change impacts on ecosystem services that will yield the greatest returns from investigation? In all questions, we measure ecosystem services through the effects on fisheries, biodiversity, and social/cultural systems.
Addressing these questions requires building an integrated ecological-socioeconomic model. We continue to develop three of the subcomponents of the integrative model: (I) a simulation model of climate change impacts and mangroves acreage on the state of Caribbean coral reefs; (II) a trophic model of fish standing crop and production; and (III) a model to predict how fishing pressure, tourism development, and local economies will be affected by climate change stressors. Model development and parameterization is primarily based on our unique data set with meta-analysis and data mining of the literature employed when needed.
Progress Summary:
After a project meeting in September 2005 in Monterey, CA, our team decided to take four parallel paths for the first year with a team and project leader for each of the components of the analysis. The lines of research within each path have proven very fruitful, and the decision was made to continue down this path for an additional year. These discussions were carried out during our monthly conference call (first Friday of each month) and confirmed during our second project meeting in January 2007 in Davis, CA. Our goal is still to combine the subcomponents, each of which is designed with the linkages/interdisciplinary questions in mind, during the current phase of the grant.
Numerical Model of Climate Change Impacts and Mangroves on the State of Caribbean Coral Reefs
Initial progress in (I) is an extension to a model of coral-algal-grazer-disturbance interactions to investigate the potential consequences of climate change upon different areas in the Caribbean. Projected temperatures and historical sea surface temperature (SST) climatologies are used to develop a time series of bleaching probabilities for each year from 2010 to 2100 under two emissions scenarios. (Simon Donner [Princeton] provided projected SSTs obtained with the use of the Hadley Centre’s HadCM3 coupled atmosphere-ocean general circulation model, together with climate data from the Intergovernmental Panel on Climate Change [IPCC] Special Report on Emissions Scenarios.) SSTs and bleaching probabilities vary with spatial location, as does predicted hurricane intensity. Collaborations have recently been extended to include the UK Meteorological Office, and we hope to use their latest, in-house, climate models and discuss their application.
Corals are modeled to suffer partial and whole-colony mortality as a result of bleaching. Species are affected differently by raised temperatures (parameterized with data from the literature), and corals that have previously been exposed to elevated SSTs are modeled to be less likely to suffer partial mortality due to bleaching. We have collaborated with the National Oceanic and Atmospheric Administration’s (NOAA) Coral Reef Watch (Dr. Mark Eakin) to access their in-house data on the effects of the 2005 bleaching event on coral mortality. These data—which are the most detailed for bleaching-induced mortality available—are now being used to generate a new bleaching parameterization. Outcomes of the model focus on the impact of different grazing levels of parrotfish upon interactions taking place in various locations across the Caribbean.
Preliminary findings demonstrate that while simulated bleaching events occur with high frequency over the 90-year period, high levels of grazing by urchins and parrotfish can prevent a significant decline in coral cover.
Using the simulation model in combination with a new three-state analytical model of corals, macroalgae, and grazed algae, we have shown that after the mass mortality of the urchin Diadema antillarum in 1983, Caribbean reefs became susceptible to changing from one stable state to alternate community states that were also stable. This is a dramatic example of hysteresis in a natural system. Outcomes of the model define critical thresholds of grazing and coral cover beyond which resilience is lost. Most grazing thresholds lie near the upper level observed in nature suggesting that reefs are highly sensitive to parrotfish exploitation.
To investigate the ecosystem-level consequences of elevated parrotfish densities in connected ecosystems, the simulation model has been extended to incorporate the impacts of mangroves on two habitats: shallow forereefs (depth 3–6 m) and deeper Montastraea reefs (depth 7–20 m). Grazing determined the vulnerability of the reef ecosystem to sudden phase changes. Mangrove impacts on grazing were significant in Montastraea reefs because their magnitude coincided with the zone of system instability. A modest change in grazing was able to shift the reef from an algal-dominated to a coral-dominated state. System instability was absent from shallow reefs, due to higher grazing levels.
Peter Mumby also convened a workshop on the effects of climate change on the incidence of coral diseases in the Caribbean at Cornell University in June of 2007.
Trophic Model of Fish Standing Crop and Production
We continue to develop a trophic model to understand the complex dynamics between representative grouper (Nassau grouper, Epinephelus striatus), parrotfish (Stoplight parrotfish, Sparisoma viride), and snapper (Yellowtail snapper, Ocyurus chrysurus) species. The model is designed to predict the subsequent changes in trophic structure due to shocks to the marine environment, such as increases in sea level temperatures or changes in anthropogenic uses (e.g., creation of a marine reserve). Initial parameterization of the model has been undertaken, and we are currently exploring the stability of the model under equilibrium conditions and the sensitivity of target species population sizes to variation in key parameters including predator abundance and fishing- and habitat-mediated mortality rates. Model results will be presented at the annual meeting of the Ecological Society of America, August 5–10, 2007.
We are also utilizing direct comparison of measures of foodweb complexity based on our survey data to investigate differences in foodweb structure associated with factors including the level of fishing pressure and extent of mangroves in the Bahamas. Further comparisons, utilizing the “niche model” approach, are being conducted based on the empirically observed variation in number of species and connections across survey locations. In addition, we compare the potential effect of species loss across coral reef foodwebs by simulating both the directed and random loss of species and measuring robustness in terms of secondary extinctions. These analyses provide insight into how foodweb structure affects the degree to which perturbations, human-induced and otherwise, are transmitted throughout fish communities. Results of these analyses will be presented at the annual meeting of the American Fisheries Society, September 2–6, 2007.
Socioeconomic Model To Predict Fishing Pressure, Tourism Development, and Local Economies Are Affected by Climate Change Stressors
The socioeconomic team continues to analyze the fieldwork data and develop a bioeconomic model to couple with (I) and (II) that includes functional dependencies between mangrove and coral reef habitats. Recent efforts have focused on linking up the location of fishing sites with catch statistics and habitats in a GIS framework. Model development is guided by our fieldwork that focuses on the interaction between local residents and their marine environment. The fieldwork includes more than 200 interviews, 600 household surveys, extensive participant observations, and participatory mapping of resource-use areas in six Bahamian settlements in Abaco, Bimini, Eleuthera, and San Salvador from 2001-2005.
We are in the process of writing up our findings that reveal a number of relevant issues: (1) Significant geographic and socioeconomic diversity exists, implying that responses in one settlement may not correspond to those in other settlements. Understanding the underlying factors driving this diversity will enable us to predict likely responses to climate change. (2) Local knowledge is important for adaptation to climate change stressors. (3) Demographic trends are potentially exposing the settlements to greater risks from climate change, such as more individuals getting involved in tourism-related activities than fishing and an increasing number of women entering the wage-based economy. (4) Locals identified several land-based threats to coral reef-mangrove ecosystems, such as leaching from local dump sites and large tourist developments.
Integrative Modeling
We have made considerable progress linking up a model of mangrove habitat, coral reef fish population dynamics, and behavioral model of fishers (fishing effort). Specifically, we address the following question: How can we capture the production value of the mangrove habitat in terms of the coral reef fish population to help inform a coastal planner on what the costs of converting the mangrove habitat are? What we find is that from an economist’s perspective, the mangroves are similar to the machines and other inputs that produce economic outputs (here, the coral reef fish). Unlike labor, where there is a market to determine the going wage rate, no market exists for this ecosystem function. We can, however, calculate the value of the mangroves by incorporating their role in species population dynamics. To do so, we use bioeconomic analysis to investigate the difference in the value of a fishery with and without the mangroves present.
Our findings show that for any number of fishing boats and fishermen, the profits from fishing are greater with the mangroves present than without them. This benefit results from the greater abundance of fish that are protected from predators by the refuge in nearby mangroves. Another interesting implication of having coastal mangroves in the vicinity of the coral reefs is that the fishery can support greater levels of fishing effort than without the mangroves. We can measure the value of the mangrove or “mangrove effect” by simply calculating the difference between fishing profits with and without mangroves present.
The size of the mangrove effect depends in some complicated ways on ecology, economics, and governance—how the fishery is managed. On the ecological side, what matters is how the species utilize different habitats in their life cycle and where the fish are subject to the greatest levels of predation. On the economic side, the size of the mangrove effect depends on the price of the fish and the costs of fishing. For example, the higher the price or lower the fishing costs, the greater the value, holding all else the same. In terms of governance, the potential value depends on how many fishing vessels are permitted to fish and the nature of their rights to the total catch. If local fishery managers do not implement rights-based tools, such as a harvesting cooperative or individual fishing quota system, then there might not be any value to the fishery from the mangroves. The important role of governance and institutions in determining the value of ecosystem services is a point often lost in discussions on the provision of these services.
In addition to making advances understanding a complex dynamical system and the cost of conversion, this line of research has illuminated the effects of the implicit (and too simplified) assumptions that economists typically make when they are including habitat into their bioeconomic models.
We also continue to make progress linking the subcomponents I, II, and III, but some of this progress was put on hold to further explore the advances in each area. Some of the potential links we plan to explore between (II) and (III), for example, include indirect effects through the impacts of fishing on grouper, a major predator of parrotfishes, and effects of fishing/reserves on potential resilience of reefs through impacts on grazers.
Ongoing model development and data analysis of Caribbean coral reef ecosystems is continuing to develop a new understanding of changes in ecological services due to climate stressors, to provide a framework for evaluating different management scenarios on ecosystem services, and to highlight mechanisms where climate stressors can cascade through the ecological and socioeconomic systems triggering responses that increase the vulnerability of the ecosystem.
Future Activities:
- Using the coral-algal-grazer simulation model we intend to generate predicted levels of coral cover for different regions, based upon the predicted frequency of coral bleaching and hurricane events. We have developed a new reserve-selection tool capable of integrating both climate and socio-economic data into the marine reserve design process. The predicted level of coral cover for each site can be incorporated into the reserve-selection process to determine sustainable networks of reserves in the presence of climate change.
- Further refinement of the parrotfish-grouper-snapper trophic model with inclusion of mangrove habitats.
- Further analysis of fieldwork data. We will also continue to analyze the model of mangrove habitat and coral reefs. This will include expanding the model to consider the tourism sector and not just fisheries. For example, tourism development can lead to clearing of mangrove habitats that can have knock on effects on abundance of local species, fishing pressure, and the resilience of the reefs to climate change.
- The advances in (1), (2), and (3) will be integrated.
Journal Articles on this Report : 13 Displayed | Download in RIS Format
Other project views: | All 75 publications | 38 publications in selected types | All 38 journal articles |
---|
Type | Citation | ||
---|---|---|---|
|
Baskett ML, Micheli F, Levin SA. Designing marine reserves for interacting species: insights from theory. Biological Conservation 2007;137(2):163-179. |
R832223 (2006) |
Exit Exit |
|
Chapman DDF, Pikitch EK, Babcock EA. Marine parks need sharks? Science 2006;312(5773):526-528 (comment on Science 2006;311(5757):98-101). |
R832223 (2005) R832223 (2006) |
|
|
Fraschetti S, D’Ambrosio P, Micheli F, Pizzolante F, Bussotti S, Terlizzi A. Design of marine protected areas in a human-dominated seascape. Marine Ecology Progress Series 2009;375:13-24. |
R832223 (2006) |
Exit Exit |
|
Halpern BS, Selkoe KA, Micheli F, Kappel CV. Evaluating and ranking the vulnerability of global marine ecosystems to anthropogenic threats. Conservation Biology 2007;21(5):1301-1315. |
R832223 (2006) |
Exit |
|
Harborne AR, Mumby PJ, Micheli F, Perry CT, Dahlgren CP, Holmes KE, Brumbaugh DR. The functional value of Caribbean coral reef, seagrass and mangrove habitats to ecosystem processes. Advances in Marine Biology 2006;50:57-189. |
R832223 (2005) R832223 (2006) |
Exit Exit |
|
Hilborn R, Micheli F, De Leo GA. Integrating marine protected areas with catch regulation. Canadian Journal of Fisheries and Aquatic Sciences 2006;63(3):642-649. |
R832223 (2005) R832223 (2006) |
Exit Exit |
|
Mumby PJ, Dahlgren CP, Harborne AR, Kappel CV, Micheli F, Brumbaugh DR, Holmes KE, Mendes JM, Broad K, Sanchirico JN, Buch K, Box S, Stoffle RW, Gill AB. Fishing, trophic cascades, and the process of grazing on coral reefs. Science 2006;311(5757):98-101. |
R832223 (2005) R832223 (2006) |
Exit |
|
Mumby PJ, Hedley JD, Zychaluk K, Harborne AR, Blackwell PG. Revisiting the catastrophic die-off of the urchin Diadema antillarum on Caribbean coral reefs: fresh insights on resilience from a simulation model. Ecological Modelling 2006;196(1-2):131-148. |
R832223 (2005) R832223 (2006) |
Exit Exit Exit |
|
Mumby PJ. Connectivity of reef fish between mangroves and coral reefs: algorithms for the design of marine reserves at seascape scales. Biological Conservation 2006;128(2):215-222. |
R832223 (2005) R832223 (2006) |
Exit Exit |
|
Mumby PJ. The impact of exploiting grazers (Scaridae) on the dynamics of Caribbean coral reefs. Ecological Applications 2006;16(2):747-769. |
R832223 (2005) R832223 (2006) |
|
|
Mumby PJ, Harborne AR, Williams J, Kappel CV, Brumbaugh DR, Micheli F, Holmes KE, Dahlgren CP, Paris CB, Blackwell PG. Trophic cascade facilitates coral recruitment in a marine reserve. Proceedings of the National Academy of Sciences of the United States of America 2007;104(20):8362-8367. |
R832223 (2006) |
Exit Exit Exit |
|
Sanchirico JN, Wilen JE. Sustainable use of renewable resources: implications of spatial-dynamic ecological and economic processes. International Review of Environmental and Resource Economics 2008;1(4):367-405. |
R832223 (2006) |
Exit |
|
Worm B, Barbier EB, Beaumont N, Duffy JE, Folke C, Halpern BS, Jackson JBC, Lotze HK, Micheli F, Palumbi SR, Sala E, Selkoe KA, Stachowicz JJ, Watson R. Impacts of biodiversity loss on ocean ecosystem services. Science 2006;314(5800):787-790. |
R832223 (2006) |
Exit Exit |
Supplemental Keywords:
marine, estuary, ecological effects, ecosystem, susceptibility, aquatic, integrated assessment, sustainable development, habitat, organism, environmental assets, conservation, public policy, decision making, social science, ecology, biology, mathematics, modeling, analytical, landsat, remote sensing, EPA region 2,, RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, Aquatic Ecosystems & Estuarine Research, climate change, Air Pollution Effects, Chemistry, Monitoring/Modeling, Aquatic Ecosystem, Environmental Monitoring, Ecological Risk Assessment, Atmosphere, environmental measurement, meteorology, climatic influence, global ciruclation model, coral reefs, global change, climate, tidal marsh, socioeconomics, climate models, ecosystem indicators, aquatic ecosystems, environmental stress, coastal ecosystems, global climate models, coral reef communities, ecological models, climate model, ecosystem stress, sea level rise, Global Climate Change, atmospheric chemistry, climate variabilityRelevant Websites:
Peter Mumby’s Coral Reef Video web site: http://www.reefvid.org Exit
NSF Bahamas Biocomplexity project web site: http://bbp.amnh.org/website/home.html Exit
NCORE’s (National Center for Coral Reef Research): http://ncore.rsmas.miami.edu/ Exit
Fiorenza Micheli’s lab: http://micheli.stanford.edu/ Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.