Grantee Research Project Results
Final Report: Effects of Climate Change On Ecosystem Services Provided By Hawaiian Coral Reefs
EPA Grant Number: R832224Title: Effects of Climate Change On Ecosystem Services Provided By Hawaiian Coral Reefs
Investigators: Jokiel, Paul L. , Beukering, Pieter van , Fautin, Daphne , Cesar, Herman , Buddemeir, Robert
Institution: University of Hawaii at Honolulu , Cesar Environmental Economics Consulting , Vrije Universiteit , University of Kansas
Current Institution: University of Hawaii at Honolulu , Cesar Environmental Economics Consulting , University of Kansas , Vrije Universiteit
EPA Project Officer: Packard, Benjamin H
Project Period: May 1, 2005 through April 30, 2009
Project Amount: $747,220
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:
Background and rationale
Coral bleaching events resulting in high coral mortality appear to have increased in frequency and severity in the last 25 years as sea-surface temperatures (SST) have risen. Global climate change, driven largely by increasing CO2 concentrations, is also associated with increased acidification of the surface layer of the ocean, resulting from an increase in the amount of CO2 that dissolves in the ocean. As the ocean acidifies, the concentration of carbonate ion in seawater is reduced, impeding the growth of corals by making it more difficult for them to form their calcium carbonate skeletons. Faced with these threats, governments and agencies involved with climate change adaptation and mitigation need realistic estimates of potential coral loss within specific regions.
Realistic forecasts will support developing coral reef management plans that will help reefs resist, recover from, and adapt to these stresses when possible, as well as supporting the adaptation of the human populations that interact with the reefs. However, modeling efforts to date either make very generalized global predictions, are focused on a single stressor or region, or are location-specific and/or data-intensive, without a framework for adapting model results for convenient local use in other locations or specific situations. Also, most existing models have focused only on the impacts from high temperature stresses (i.e., coral bleaching) without considering threats to coral reefs from acidification and other changes in ocean chemistry.
Philosophy and objectives
Modeling tools are needed that
- incorporate long-term effects of changes in both temperature and ocean chemistry on coral reefs, together with the impact of short-term high temperature (bleaching) events;
- have flexibility to incorporate relevant regional or local data and expert judgment, and to allow scenario testing and habitat comparisons;
- can be used by biologists, reef managers, and policy-makers who lack resources and/or expertise for complex modeling or model development; and
- can be readily modified or linked to other models (e.g., socioeconomic impact).
Task objectives were to meet these needs for a coral-climate ecosystem impact modeling and decision support tool by providing an accessible, flexible, user-friendly analytical simulation model platform that could predict potential effects on coral reefs of temperature increases and ocean chemistry changes caused by climate change. Key features to be included in the model were options for the user to input data or modify calculations, and for the inclusion of adjustable variables representing all the major factors controlling coral responses to environmental change that can be adequately quantified at present.
Summary/Accomplishments (Outputs/Outcomes):
Implementation and design
The COMBO model provides COral Mortality and Bleaching Output. Development of the model actually started prior to the initiation of the STAR Grant when RWB was contacted by Stratus Consulting to participate in the development of an EPA-sponsored model (Office of Atmospheric Programs) of climate impact on reefs as input to a global climate change impacts model. The ideas being explored for that project were further developed and focused for the STAR Grant project. Consistent with the original purpose, three versions have been prepared, tailored to the conditions in the Hawai’ian archipelago, the Australian Great Barrier Reef, and the Caribbean region; in recognition of the leadership of the STAR Grant, the Hawai’i version has been the primary development and testing platform.
The model honors the scientific community’s accepted generalizations about coral behavior and response and provides default values and relationships for use in the target areas. However, it can be adapted to any region, as it also contains extensive options for input of local data, exercise of expert judgment, and modification of the underlying model structure by anyone familiar with spreadsheet calculations. Thus, the COMBO model both serves as a modeling or model development tool and provides a “ready-to-use” simulation model for areas and coral reef conditions represented by the default data inclusions, or for educational purposes. Fig. 1 illustrates the model’s functional structure.
Figure 1: Functional outline of the COMBO Model.
The model is constructed in the form of a Microsoft Excel workbook with multiple interacting worksheets containing the various modules and functions. All calculations are user-accessible (i.e., no coding is employed), and this transparency, combined with the use of a calculation platform that is widely used in many fields, means that the user can both evaluate and modify the modeling procedures as needed.
Dissemination and applications
During the early developmental stages, an access-controlled Google Group site was established (COMBO Model Users -- http://groups.google.com/group/combo-model?lnk=iggc) to distribute model versions and other information to project participants and other testers; a website was established to support the project, with particular reference to the model development (http://geoportal.kgs.ku.edu/coralclimate/). At the end of the project, this URL was converted to a model download and information site, and is now the primary source to which potential users are directed.
The model was described and results of trial applications were presented in the peer-reviewed open-access publication:
Buddemeier RW, Jokiel PL, Zimmerman KM, Lane DR, Carey JM, Bohling GC, Martinich JA. 2008. LIMNOLOGY AND OCEANOGRAPHY-METHODS Volume: 6 Pages: 395-411 Published: SEP 2008
Application of COMBO in support of a World Bank socio-economic study of climate change in the Caribbean region was made independently of (but in consultation with) project participants:
Vergara, W. (Ed) 2009. Assessing the Potential Consequences of Climate Destabilization in Latin Americal. Sustainable Development Paaper 32, World Bank Latin America and Caribbean Region sustainable Development Department, 115 pp.
At least two further COMBO-based papers have been submitted to journals; one based on the Vergara World bank report, and
R.W. Buddemeier, D.R. Lane, J.A. Martinich, Modeling Regional Coral Reef Responses to Global Warming and Changes in Ocean Chemistry: Caribbean Case Study. Submitted to Climatic Change, May 6, 2009
In addition, COMBO was used by the EPA’s Office of Climate Change in a study of power plant impacts, and is listed in the NODA on Ocean Acidification.
Follow up work continues to bring the Caribbean model and GBR Model versions (and documentation) up to the Hawai’i model standards. When that is accomplished, general announcements will be made on appropriate list-servers.
Task: Ocean Acidification Studies, Impact of Climate Change on Hawaiian Archipelago Task Leader/Co-investigator: Paul L. Jokiel
Members:Ku’ulei Rodgers, Hawaii Institute of Marine BiologyIlsa B. Kuffner, U.S. Geological Survey,Andreas J. Andersson, Bermuda Institute of Ocean SciencesFred T. Mackenzie, University of Hawaii Department of OceanographyEvelyn F. Cox, Hawaii Institute of Marine BiologyRon Hoeke, Coral Reef Ecosystem Division, NMFS, Honolulu
Background and rationale:Although there is abundant information on the effect of temperature on Hawaiian corals, there was no data on the effect of ocean acidification. Therefore a long-term mesocosm investigation was undertaken to determine the impact of a doubling of atmospheric CO2 on Hawaiian biota. Twice present day CO2 is the level expected to occur before the end of this century unless action is taken to reduce global fossil fuel CO2 emissions.
After completion of the COMBO model (See first section of this report), we undertook a more detailed comparison of projected changes throughout the Hawaii region from Midway Atoll in the north southward to French Frigate Shoals, Oahu, and to Johnston Atoll in the south. These regions undergo very different annual temperature regimes, so the outcome could vary. Also, a more advanced modeling technique for determining the variability of the future signal was developed and a much more rigorous analysis undertaken using multiple climate models and a more complex method of calculating seasonal and annual variations in future temperature projections.
Findings:Results of this task are contained in 4 papers that are now published the peer reviewed literature with one manuscript in review (see section 3 of this report). Our research showed the following changes due to a doubling of present day CO2:
- The major new discovery is that crustose coralline algae (CCA) is highly vulnerable to ocean acidification. This is because they secrete high Mg carbonate rather than aragonite. High Mg carbonate has higher solubility.(Kuffner et al. 2008).
- CCA recruitment decreased by 78% under acidified conditions and CCA cover decreased by 92% in short term (7week) experiment. (Kuffner et al. 2008).
- Fleshy algae increased cover by 52% in the short term experiment.(Kuffner et al. 2008).
- CCA nodules known as rhodoliths showed a dramatic response to ocean acidification.
During a long term (9 month) mesocosm the rhodoliths grew in control but dissolved in the acidified treatment (twice present day pCO2) for a net reduction of 250% (Jokiel et al. 2008)
- Long term (9 month mesocosm experiment) showed reduction in CCA cover of 84% on hard surfaces in the acidified treatement. (Jokiel et al. 2008)
- At the end of the long term ocean acidification experiment the area of bare surface on the tank walls was 46% higher in the acidified treatment due to lower recruitment of biota.
This suggests that none of the organisms in the community could exploit the vacant space under acidification conditions. (Jokiel et al. 2008)
- Coral calcification rate reduced by 15-20%, which is similar to other previous estimates. (Jokiel et al. 2008)
- No difference in coral gamete production or coral recruitment, which is consistent with results of other recent investigations (Jokiel et al. 2008). Ocean acidification will primarily impact calcification and not organic processes.
- Other invertebrates such as vermetids, oysters, barnaclus showed trend of slightly decreased calcification, but the major impact will be on CCA and coral growth. (Jokiel et al. 2008)
- At the end of the long term mesocosm experiment the net ecosystem calcification was +4.5 mmol CaCO3 h:1 at present seawater pCO2 and 0.1 mmol CaCO3 h:1 at twice present day concentration (Andersson et al. 2009). The paradox is that at twice present day pCO2 reefs will be dissolving while the corals are still growing.
- Different patterns of temperature change at different locations in the Hawaiian Archipelago lead to different probabilities of the onset of frequent bleaching and subsequent rates of recovery (Hoeke et al. manuscript, see Part IV of this report).
Nevertheless the long-term outlook for coral reefs is bleak so long as we continue the“business as usual” scenario of adding fossil CO2 to the atmosphere.
Conclusions:
- Ocean acidification will primarily impact calcification and dissolution of calcium carbonate with substantial differences in response between various taxonomic groups.
- Coral calcification will decrease due to increasing ocean acidification but the impact on crustose coralline algae calcification will be much more severe.
- Bleaching and coral mortality events are highly visible, but the insidious degradation of reefs due to ocean acidification, pollution, sedimentation and over fishing must be considered in forecasting the future of coral reefs and in management actions.
- There will be large regional and local differences throughout the Hawaiian Archipelago in the rate of decline of reefs, but the trend is similar at all locations with near total elimination of corals by the end of the century unless action is taken to stabilize the climate (Buddemeier et al. 2008, McLeod et al. 2008).
Task: Socioeconomic Analysis
Task Leader/Co-investigator: Pieter BeukeringTeam Members: Sonya Garcia, Wolfgang Haider, Zeke Hausfather, Yi Liu, Kate Shapiro
Background and rationaleThroughout this study, the following questions were addressed:
- What are the willingness to pay ranges for climate change mitigation efforts by US residents (both Mainland and Hawaiian)?
- What is the value of the ecosystem services provided by Hawaiian coral reefs?
- What are the values of the individual components of coral reef ecosystem services?
- What is existence value of Hawaiian coral reefs to both Mainland and Hawaiian residents?
Implementation and design
In order to address these questions, a choice model was developed and administered via an online survey to a sample of both the Mainland US resident and Hawaiian resident populations. The use of a choice model was critical to the study as it allowed for specific attributes of coral reefs to be valued separately in relation to climate change.
Summary of findings: 1. Choice Model (see Part II of this report)
Characteristics of sample populations
- There were differences in the socio-demographics of the survey sample respondents from the US mainland versus the sample from Hawaii. Prominent differences in income, employment status and age may explain variations in the results and could help to determine potentially specific policy development and management plans for each sample population.
- Hawaiian and Mainland populations can be separated into climate believers and climate skeptics, both of whom behave differently with respect to willingness to pay for climate change mitigation and gain varying amounts of utility for the attributes of the coral reefs that were presented.
- The presence of heterogeneity within the sample populations is further evidence that potential climate change mitigation policies will have to deal with varied opinions and preferences within each sample. The latent class model shows that both US Mainland and Hawaiian residents can be segmented into 3 classes that behave differently with respect to utility gained from coral reef attributes, and their willingness to pay for climate change mitigation. These 3 classes can be labeled; pro-mitigation climate believers, antimitigation climate believers and anti-mitigation climate skeptics.
Characteristics of attribute utility
Results show that both US Mainland and Hawaii sample populations gain varying degrees of utility fromthe attributes that comprise a coral reef. Understanding these variations is useful in order to properly form meaningful and compliable policies and management plans. The results for the attributes can be summed up as follows:
- Water clarity: positive, linear, steeper utility for Mainland than Hawaiian, showing that Mainland residents gain greater utility than Hawaiians from water clarity. This may be explained by the functional requirements and aspects of reefs for Hawaiians as opposed to strictly recreational requirements for mainland residents.
- Coral cover: positive, linear, steeper utility form for Hawaiian residents. May be explained by the utility gained by increased coral cover for such functions as erosion control, fish habitat, (i.e. use values), as opposed to simply aesthetic purposes derived from Mainland residents using the reefs for recreation.
- Coral Health: Mainland residents show positive linear form, only 2 levels show significance. Hawaiian residents show quadratic form. Only one level displays significance.
- Fish Numbers: slightly positive linear form. Non-significant for Mainland residents, significant for Hawaiian residents
- Species Diversity: Only one level shows significance; Hawaiian results show sporadic form, not significant.
- Mitigation Fee: Negative, linear form, clearly showing decline in utility as mitigation fee increases. Significant for both populations.
Willingness-To-Pay ranges
The construction of a Decision Support System (DSS) was crucial in understanding the public’s willingness to pay for climate change mitigation, and thus the existence values derived from the Hawaiian coral reefs. The DSS is to be used as a decision making tool for policy planners and managers when making decisions regarding potential introductions of climate change taxes relating specifically to coral reefs.
- According to the DSS, the results show that the 95.2% of the Mainland population is willing to pay upwards of $407.29 for the greatest possible reef improvement, while 97% of the Hawaiian population is willing to pay $109.82 for the same level of improvement.
Separation of Use and Non-Use Values
One of the innovative aspects of this research, and the application of the ChoiceExperiment, is that we were able to separate the use and the non-use values within the same survey. This is important for a number of reasons. By separating the different values, we are able to assess the variations in people’s willingness to pay, depending on their relationship to a given environmental service, coral reefs in this case. As well, we are then also able to look at variations in individual responses and make comparisons between the values that are placed on individual attributes of a coral reef. As was determined, different values (both use and non-use) are placed on the coral reef attributes depending on whether or not respondents were from the Hawaiian, or Mainland survey samples.
Presence of charismatic species
Though it may seem to go against intuition, the results clearly show a decline in utility when a charismatic species such as a turtle is present in the coral reef scenarios. Upon further inspection, it becomes evident that the utility from the presence of a turtle is directly affected by the relationship between the presence of a turtle and the other attributes within the choice sets. As coral cover and health decline, the utility for the turtle decreases and respondents display a higher willingness to pay for climate change mitigation. Conversely, when coral health and cover are at their highest, the presence of a turtle is seen as an added bonus, showing increased utility for respondents, thereby resulting in a lower willingness to pay for climate change mitigation. This shows that respondents value the overall health of the reef as more important than the presence of a charismatic species like a turtle.
Decline Index
Results show that the decline index was an important factor in respondent decision making. Understanding the relationship between the decline index from the current situation and the relationship between the Without Mitigation and With Mitigation options provides valuable insight into preferences for coral reef mitigation. As the level of decline increased, respondent utility for the Without Mitigation option decreased a well. The important relationship here is that the greater the decline from the Current Scenario,
the higher the willingness to pay for climate change mitigation. Preferences for the With Mitigation option increased substantially as the improvement index increased from the Without Mitigation option. These results tell us that in a scenario where there is minimal decline from the Current Scenario; respondents are more likely to choose the Without Mitigation option, especially when the improvement to the With Mitigation option is also minimal. As the level of decline increases from the Current Scenario, respondents are more likely to choose the With Mitigation option, clearly showing that mitigation is preferred over
allowing the coral reefs to degrade.
Climate change research in general
- The results of this study show that there is a willingness to pay for climate change mitigation that can be applied to potential tax increases. These tax increases can then be used to fund climate change research and mitigation strategies.
- The part worth utility estimates resulting from the latent class models show that there is strong utility derived from improvements to specific attributes, more so than others. In the realm of climate change research, this may be used to show that (particularly for Mainland US residents) improvements to coral attributes provide greater utility than improvements to fish attributes.
- The fact that climate belief was the most significant covariate, could be useful in showing that there is still 25% of the population that is skeptical about climate change, and therefore more research may be required to provide concrete evidence of the causes, impacts and implications of climate change, specifically on coral reefs.
- Results show that climate change is obviously an important factor that influences the changes in utility derived by recreational coral reefs users. Further longitudinal studies on changing recreational preference values resulting from climate changes may help to shed light on specific areas of mitigation that the public may be most willing to pay for.
Research on existence value
As the climate change mitigation fee question was framed using the PMNM, a marine protected area that essentially limits access to the general public, results show the majority of people are willing to pay at least some dollar value to improve reef conditions in locations that they themselves do not have access to. This shows a general willingness to pay for the pure existence of the coral reefs, and may help to boost support for further research on various aspects of existence valuation.
Research on ecosystem services
Ecosystem services play a crucial role in maintaining the ecological balance of our earth. By breaking down the attributes of the coral reefs and providing willingness to pay estimates for those attributes, connections can be made to the direct and indirect services provided by the reefs in general as well as the services provided by the individual attributes of those reefs. If arguments can be made that the services provided by certain ecosystems (coral reefs in this case) are in fact of value to the public, especially if that value is not associated with a direct use, then there may be potential for policymakers to initiate stronger conservation and preservation measures.
What does this all mean for policy?
The results of this study have the potential to guide future policy and project decision making , and will be useful for policy makers and managers in deciding how to secure adequate coastal zone management funding and who should pay, how much they should pay, and what they can charge for with respect to climate change mitigation. Results from this study also show that both use and non-use values should be considered when assessing the value of a given location. In other words, it is important that the concept of total economic value be applied to potential policies.
Detailed location specific values should be determined based on the attributes of the coral reefs in that location. This may help inform policy development, especially for implementation of marine protected areas, since based solely on average values, the value of a given location may be significantly overestimated or underestimated.
Clearly, the results show drastically different willingness to pay estimates between the Mainland US and Hawaiian populations.
Though the Hawaiians receive the greatest direct use utility from the coral reefs surrounding the Main Hawaiian Islands, their willingness to pay for climate change mitigation for the PMNM is significantly lower than that of the Mainland. This may be because Hawaiians feel that any climate change mitigation efforts should instead go directly towards saving the reefs that directly support their lifestyle, economy and culture.
Hawaiians (specifically, native Hawaiians) are much more fish-oriented, because of the vicinity of the sea and their cultural interest in fishing. These cultural interests as well may provide the Hawaiians with different values (use, or non-use) from specific attributes of the coral reefs, thereby possibly altering their willingness to pay for mitigation fees that they feel may change the structure and function of the entire reef community.
Mainlanders are less marine oriented and thus see turbidity as hazardous pollution rather than as (relatively harmless) run-off. As well, diversity and health are hard to grasp by laymen respondents who may not be as familiar with marine attributes. It is more likely that the majority of Mainland respondents would require more knowledge of marine attributes in order for them to make informed decisions similar to those of the Hawaiian respondents.
Because of this, it would be prudent for policy makers to develop tax structures that appropriately target the varied reef user groups. What is exactly the implication for policy in terms of targeting the Hawaiian and Mainland population?Results show that the highest utility was achieved by improving such attributes as water clarity, coral cover and coral health. Knowing this could help policy makers and managers frame any proposed mitigation strategies that would be funded by tax increases. The public may be more willing to pay for mitigation research, when they are told that the research will specifically be addressing potential improvements to the attributes, as opposed to simply stating that they will be attempting to improve reefs as a whole.
Understanding the presence of heterogeneity within the survey populations may also help to define who should pay, and how much they should pay. As the results show 3 distinct classes within each survey population, clearly delineating groups of respondents who are pro-mitigation or anti-mitigation, climate believers or climate skeptics. Knowledge of these heterogeneous groups may be useful in developing policy for various tax structures that target sociodemographic backgrounds.
Understanding the value of ecosystem services provided by Hawaii’s coral reefs address the notion of placing an existence value on those reefs and thereby provides estimates for adequately funding research into climate change mitigation strategies.
2. Hedontic Model (see Brouwer et al. manuscript, see Part III of this report)
A spatial hedonic price model for residential property in Hawaii and the possible impact of coral reef on amenity values was developed. Using GIS, available house market data for the islands Oahu, Big island, Maui and Kauai over the period 2000-2007 are linked to spatially defined census, land use and coral reef monitoring data. Significant linear and non-linear decay effects were found for houses located at different distances from the coast. Whilst controlling for structural, neighborhood and location characteristics, significant distance-decay effects were detected for different coral reef structures. Adding the distance of a house to the nearest reef structure and the share of live coral in buffer zones drawn as concentric circles around the nearest point from each house to the coast results in a relatively small, but statistically significant improvement of the model’s explanatory power, suggesting that coral reef has a significant impact on house prices, both in terms of presence and quality.
References:
Journal Articles on this Report : 5 Displayed | Download in RIS Format
Other project views: | All 47 publications | 6 publications in selected types | All 5 journal articles |
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Andersson AJ, Kuffner IB, Mackenzie FT, Jokiel PL, Rodgers KS, Tan A. Net loss of CaCO3 from a subtropical calcifying community due to seawater acidification: mesocosm-scale experimental evidence. Biogeosciences 2009;6(8):1811-1823. |
R832224 (Final) |
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Buddemeier RW, Jokiel PL, Zimmerman KM, Lane DR, Carey JM, Bohling GC, Martinich JA. A modeling tool to evaluate regional coral reef responses to changes in climate and ocean chemistry. Limnology and Oceanography: Methods 2008;6:395-411. |
R832224 (Final) |
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Hilderbrand R, Utz R, Stranko S, Raesly R. Applying thresholds to forecast potential biodiversity loss from human development. BRIDGES 2010;29(3):775-1183 |
R832224 (Final) |
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Jokiel PL, Rodgers KS, Kuffner IB, Andersson AJ, Cox EF, Mackenzie FT. Ocean acidification and calcifying reef organisms: a mesocosm investigation. Coral Reefs 2008;27(3):473-483. |
R832224 (Final) |
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Kuffner IB, Andersson AJ, Jokiel PL, Rodgers KS, Mackenzie FT. Decreased abundance of crustose coralline algae due to ocean acidification. Nature Geoscience 2008;1(2):114-117. |
R832224 (Final) |
Exit Exit |
Supplemental Keywords:
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, global change, Hawaii, climate models, UV radiation, ecosystem indicators, aquatic ecosystems, environmental stress, coastal ecosystems, global climate models, coral reef communities, ecological models, climate model, ecosystem stress, Global Climate Change, atmospheric chemistryProgress 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.