An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Land and Sea: Linking Ecosystem Services with Local Concerns in Guanica Bay Watershed, Puerto Rico

Guanica BayCoral reefs are some of the most diverse and productive ecosystems on earth, but they are also among the most fragile. Over fishing, habitat degradation, climate change, and pollution and sedimentation from tainted stormwater running off nearby land are all taking their toll. Declines are estimated to have claimed twenty percent of the world’s reefs. The United States Coral Reef Task Force—comprised of leaders from EPA and 11 other federal agencies along with select States, Territories, and Commonwealths—was established in 1998 to stem loses and preserve and protect coral reef ecosystems.

A key strategy of the Task Force has always been to build partnerships with local communities to develop joint strategies that match conservation actions with local, on-the-ground conditions. An early priority was Puerto Rico’s Guánica Bay, where the health of the reefs was under threat from deteriorating water quality from sediment and nutrient pollution flowing off of the surrounding watershed.

To support that effort, EPA researchers have been leading and conducting studies to better understand the links between Puerto Rico’s coral reefs, the water quality of Guánica Bay, and land use across the watershed. They have conducted systematic assessments of the health of the reef, quantified the flow of sediments and nutrients from the freshwater sources flowing into the Bay, and mapped land use patterns and habitat across the watershed and the island of Puerto Rico.

Results from that work were used to inform a 2009 Task Force initiative to address land-based sources of pollution. Conservation actions identified included changes to agriculture practices, planting vegetated riparian buffers along streams, dredging reservoirs, and developing and enhancing coastal wetlands. But Task Force members and their partners soon learned that without continued stakeholder engagement, solely identifying such actions would fall short of inspiring the necessarily support and implementation needed to see them through.

EPA researchers saw their ongoing work in Guánica Bay as an opportunity to conduct a novel study identifying how to link specific benefits that flow from the environment—defined as “ecosystem service supply”—with stakeholder engagement. In their study, published in the journal Ecological Indicators, researchers examined records from coral reef workshops to identify 19 metrics reflecting the concerns of participating stakeholders, 15 related to terrestrial ecosystems in the watershed, and four in the coastal zone. The research team then applied “ecosystem service production functions” to quantify and map how management of the watershed influences nature’s benefits to humans.

“Our results suggest that actions in the watershed to protect coral reefs may lead to improvements in other ecosystem services that stakeholders care about on land,” the authors note.   

The maps the researchers created revealed how ecosystem service production is distributed throughout the Guánica Bay watershed, illuminating areas where watershed management would benefit both the community and the coral reef habitat offshore. For example, reforestation would help meet many of the community’s objectives expressed during the workshops—specifically improved air quality, the conservation of threatened wildlife, and the retention of rainwater—while also protecting the coral reef from land-based pollutants. And because the Lower Guánica region has one of Puerto Rico’s largest areas of mangrove and coral reef habitat, there would be many potential economic opportunities for marine-based recreation and fishing.

The results of the study suggest that including considerations of both ecosystems and the concerns of local stakeholders can be fertile ground for supporting coastal management decisions. “Our study illustrates that actions in the watershed to protect coral reefs may lead to improvements in other ecosystem services that stakeholders care about on land. Considerations of both coastal and terrestrial benefits in coastal management may ultimately lead to decisions that gain a greater return on investment and great stakeholder acceptance, while still achieving conservation goals,” the study concludes.


Smith, A., Yee, S. H., Russell, M., Awkerman, J., & Fisher, W. S. (2017). Linking ecosystem service supply to stakeholder concerns on both land and sea: An example from Guánica Bay watershed, Puerto Rico. Ecological Indicators, 74, 371-383.

Guanica Bay

Puerto Rico’s Guanica Bay

More EPA Puerto Rico Watershed Research

EPA research focused on the San Juan Bay Estuary is also being conducted to help local communities in Puerto Rico. Some of that work will be featured at the 2017 Society of Wetland Scientists Annual Meeting to be held in San Juan, Puerto Rico in June of 2017. Highlights include:

  • A study examining the carbon storage and greenhouse gas fluxes in the San Juan Bay Estuary for both Current trends and likely future states. Results suggest a positive relationship between urban development and both methane and nitrogen dioxide emissions, and demonstrate that San Juan Bay estuarine waters are a major methane source. The data provide a baseline for comparing against once planned restoration activities have been completed.
  • Research characterizing the organic matter in surface sediments from the San Juan Bay Estuary. Preliminary results quantify how the obstruction of the Martín Peña canal led to increased deposition, which has been associated with bottom water hypoxia, fish kills, and excessive trash accumulation. To ameliorate these problems, the canal is slated to be dredged in 2018.
  • An exploration of how a clogged canal effects ecological and human health in a tropical urban wetland ecosystem.  EPA researchers are working to document how reduced flushing and poor water quality in a canal that can no longer flow are impacting the ecology of the mangrove and lagoon ecosystems.
  • An evaluation of the prevalence of dengue fever in the San Juan Bay Estuary: Evaluating the role of Wetland Ecosystem Services. Mosquito borne diseases are an increasingly important health concern, which pose great challenges for safe and sustainable control and eradication. Agency researchers are exploring which elements in the urban environment could be managed to reduce the potential for Dengue occurrence. In particular, they are studying the potential of wetlands in the San Juan Bay ecosystem to buffer from vector proliferation.
  • Diverse Settings, Common Toolbox – Using Social-Ecological Systems Approach to Model Changes in Ecosystem Services After Wetlands Restoration. EPA researchers are using two different wetland restoration projects to model how to link decision making with considerations of ecosystem services. The two projects are a planned dredging and restoration of mangrove forests in San Juan Puerto Rico and the completed restoration of a former cranberry farm in Plymouth, Massachusetts, now gearing up for a second phase of restoration activities.