Climate Change Adaptation Strategies for Protected Areas in Puerto Rico
Sponsoring organization: Para la Naturaleza
Team members: Ari Athair (Mechanical Engineering ’20), Jacob Boles (Biomedical Engineering ’20), Brooke DePascale (Chemical Engineering ’20), & Dylan Parrow (Chemical Engineering ’20)
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Executive Summary: Climate change is a growing issue impacting natural and human systems around the world. Coastal regions are especially susceptible to the effects of climate change due to their proximity to the ocean, where many impacts manifest. Para la Naturaleza (PLN) is a private nonprofit organization that aims to monitor and protect various lands of high ecological value on the island of Puerto Rico (Para la Naturaleza, Who Are We?, n.d.). Unfortunately, PLN’s existing management plans for protected areas do not address climate change, a problem affecting ecosystems and infrastructure within the areas. Other climate change management plans in use around the world are often vague and not comprehensive. Importantly, none of the management plans we examined focused on the challenges associated with implementing strategies in protected areas. The overall goal of our project was to provide recommendations for climate change adaptation strategies for Las Cabezas de San Juan Nature Reserve and Área Natural Protegida Medio Mundo y Daguao, which can be incorporated into future management plans for protected areas monitored by PLN. We aimed to create a standardized method for proposing adaptation strategies that can be extended to other regions. To accomplish this goal, we developed three main objectives:
Assess the two sites selected by PLN to gauge the effects of climate change on existing infrastructure and natural systems. This involved the analysis of existing management plans and the utilization of online software, such as the National Oceanic and Atmospheric Administration (NOAA) Sea Level Rise Viewer and the Interactive Map of Puerto Rico. In addition, we interviewed PLN employees and conducted site visits to better understand the condition of the reserves and the climate change impacts threatening each site.- Prioritize the most critical areas, based on importance and vulnerability to climate change impacts. The importance of each site within the reserve was determined based on cultural, ecological, tourism, and infrastructural factors. Vulnerability was assessed based on the site’s susceptibility to sea level rise, coastal erosion, flooding, and extreme weather events.
- Identify potential adaptation strategies and perform a cost analysis. We compiled strategies from existing management plans that could be applicable in the two protected areas. Any strategies that we proposed to PLN are as natural, subtle, and non-invasive as possible to maintain the natural appearance of these areas.
Results
Our assessment showed that both sites will be impacted by sea level rise (SLR) and will experience partial or complete inundation in important areas. At Las Cabezas de San Juan Nature Reserve, approximately 15% of land will be inundated after one foot of SLR, 30% after three feet of SLR, and 37% after six feet of SLR. At Área Natural Protegida Medio Mundo y Daguao, approximately 44% of land will be inundated after one foot of SLR, 55% after three feet of SLR, and 62% after six feet of SLR (The Government of Puerto Rico, 2015). These sites are also being threatened by other climate change impacts including coastal erosion, storm surges, increased precipitation, an increase in frequency and severity of natural disasters, ocean acidification, and flooding. Using the information from the assessment, we prioritized sites within each reserve based on their cultural, ecological, tourism, and infrastructural importance and vulnerability to climate change impacts. Within Las Cabezas de San Juan Nature Reserve, the sites are prioritized in the following order: access road, Playa Jayuya, Playa Canalejo, Laguna Grande, Seven Seas Beach, Playa Lirios, Visitor Center, El Faro, and the boardwalk. For Área Natural Protegida Medio Mundo y Daguao the sites were prioritized as follows: mangrove forest, Medio Mundo Beach, dirt road, visitor center, Langley Drive, bridge, and the boardwalk.
We gathered potential adaptation strategies from various sources to be proposed for the protected areas. Australia’s CoastAdapt system, the San Juan Bay Estuary Climate Change Adaptation Plan, the Scottish Coastal Archeological and Problem of Erosion Trust (SCAPE) Model, and the Environmental Protection Agency’s (EPA) Synthesis of Adaptation Options for Coastal Areas all contained useful adaptation strategies. 
(Australian Government Department of the Environment and Energy, 2019; Bauzá-Ortega, 2015; Dawson, 2013; U.S. EPA, 2009). We developed other strategies with help from PLN employees Santiago Oliver Báez, Pablo Ponce De León, and Antares Ramos Álvarez (Personal Communications, 2019). We compiled these strategies and then made recommendations for specific areas as applicable. We researched past uses of individual strategies and spoke with PLN employees to gather information on approximate costs of implementation. At a minimum, we were able to provide estimates of material costs. We also included costs for labor, transportation of materials, and monitoring when this information was available.
Conclusions
The protected areas we assessed will be, or are currently being impacted by, SLR, coastal erosion, storm surges, increased precipitation, an increase in frequency and severity of natural disasters, ocean acidification, and flooding. Critical areas in need of adaptation strategies within each site were identified as those that have the most relative value, are in the most danger from climate change impacts, or both. This reported that the access road and Playa Jayuya within Las Cabezas de San Juan and the coastal mangroves and dirt access road within Área Natural Protegida Medio Mundo y Daguao should be prioritized based on their importance and vulnerability.
Utilization of volunteers and implementation of a monitoring system are important to the success of the adaptation methods. Most, if not all, of the labor involved in implementing the adaptation strategies could be completed by volunteer groups under the supervision of knowledgeable experts. This would eliminate or reduce labor costs, leaving funds for other aspects. Once implemented, a method for monitoring is required for maintenance and determining the strategies’ success (Fideicomiso de Conservación de Puerto Rico, 2010.a). This could consist of volunteers that collect data and observations at each of the sites, such as measuring and reporting rates of sea level rise or coastal erosion.
Most traditional strategies, particularly hard adaptation strategies, cannot be used in these protected areas. Because of high tourism rates and ecological vulnerability, it was necessary to consider alternative strategies, or combinations of several existing techniques to meet the needs of each area. It was essential to evaluate the aesthetic impacts of any strategies that are selected to preserve the natural appearance of these sites. An additional challenge is that some areas in the reserves are inaccessible making implementation more difficult.
It is difficult to define how quickly SLR is progressing and when impacts will begin. Organizations around the world have attempted to quantify SLR and make projections for the future. These projections typically come in the form of sea level increase from current levels to those expected in the year 2100. The high end of these projections predict a 5.9 foot SLR by the year 2100 (Ezcurra & Rivera, 2018). Low ends of similar projections indicate increases in sea level of only 0.85 feet (IPCC, 2018). These discrepancies arise from unknown rates of future carbon dioxide emissions and glacial ice melt (NOAA Office for Coastal Management, n.d.). While there is no widespread agreement on the rate of SLR, most organizations agree on the fact that it is accelerating.
PLN recognizes the potential for partial or complete loss of their sites due to sea level rise and natural disasters, despite the efforts made. Elizabeth Padilla stated that within 100 years, they expect the reserve at Las Cabezas de San Juan to be a series of islands because of sea level rise (Personal Communication, 2019). In some cases, the best option may be to do nothing and focus efforts elsewhere, while allowing natural systems to adapt.
Recommendations for Ecosystems and Infrastructures
Roads
- Maintaining vegetation on the sides of roads can protect from erosion and inundation.
- Fortify edges of road through stone placement to reduce surface erosion.
- For a long-term solution, bridges with stable foundations could be built to raise the level of the road, accommodating rising water level.
Archaeological Sites
- Focusing excavation efforts on the regions most susceptible to climate change impacts will minimize the loss of archaeological artifacts.
Mangroves
- Dead mangroves should be removed in stages while planting in coastal areas that were damaged by hurricanes and storm surges.
- Begin planting new mangroves, using the remaining dead mangroves as protection. The belt of replanting can progressively be moved outward as time and resources are available.
Beaches
- Do not build hard structures (i.e. seawalls, jetties, etc.) because these structures will cause erosion or unintended effects at other locations.
- Replanting sea grasses or restoring and planting Staghorn and Elkhorn coral in coastal reefs to strengthen natural breakwater of the reefs.
- Dune development using sand fences or collecting and baling sargassum.
Built Infrastructure
- Consider GIS projections and build in areas which are less likely to be impacted by flooding and SLR.
- Adapt infrastructure by raising existing structures in at risk areas on stilts to protect from the effects of flood damage.
- Ensure existing structures are regularly inspected and maintained. Corrosion caused by changes in humidity can weaken structures and should be identified.
- Fortifying roofs to effectively drain water will reduce impacts of extreme weather events.