We studied the water contaminant levels in the bay and the coral reef ecosystems just outside to develop a baseline environmental assessment of water quality and living marine resources of Jobos Bay. The bay is home to important marine habitats but is surrounded by farms which can adversely affect water quality in the bay through runoff of pesticides and fertilizers. The baseline assessment will be used to assess effectiveness of agricultural best management practices in the watershed.
Why We Care
Jobos Bay is Puerto Rico’s second largest estuary and home of the Jobos Bay National Estuarine Research Reserve. The Bay has a variety of important marine habitats including mangroves, salt marshes, and seagrass beds. In addition, coral reefs grow just outside of the Bay. Land based sources of pollution from agriculture, industry, and human waste, have the potential to adversely affect the environmental health of this system.
This study aimed to develop a baseline environmental assessment of Jobos Bay and adjacent marine ecosystems, such as distribution and condition of habitats, nutrients, contaminants, fish, and benthic communities. This is the first step in evaluating the effectiveness of management conservation practices in the watershed. The partnership between NOAA’s National Centers for Coastal Ocean Science (NCCOS) and the U.S. Department of Agriculture seeks to establish a collaborative long-term research and monitoring program for the bay to develop collective watershed and coral reef management and conservation options.
What We Did
We tested the waters and sediments of the Bay and nearshore waters for 162 contaminants, including heavy metals, pesticides, nutrients, hydrocarbons and other pollutants.
What We Found
We found that no sediment sites exceeded widely accepted sediment quality guidelines. We detected a variety of contaminants in coral tissue samples, but no guidelines or thresholds for acceptable levels of coral contaminants currently exist. The environmental quality of Jobos Bay is similar to what we’ve seen in other areas of the Caribbean: contaminant levels in sediments and corals are generally low. The most structurally complex reef is located seaward of Jobos Bay (rather than inside the Bay itself), and this is where we saw the highest coral cover. Sites along these reefs, as well as within the adjacent mangrove complex, had the highest fish species richness, abundance, and biomass in our study. In addition, we created a new benthic habitat map from newly acquired acoustic and optical imagery.
We also found that nutrients, the condition of fish populations, and coral reef ecosystem conditions in and around Jobos Bay are comparable to those for other coral reef ecosystems in Puerto Rico and the U.S. Virgin Islands. Their condition appears to be shaped primarily by regional-scale processes such as temperature induced coral bleaching, ocean acidification, coral disease, and overfishing, rather than pollution and contaminants. Several partners contributed to this project: USDA Natural Resources Conservation Service (NRCS), USDA Agricultural Research Service (ARS), Jobos Bay National Estuarine Research Reserve, Puerto Rico Department of Natural and Environmental Resources and NOAA's Coral Reef Conservation Program.
This assessment is complete. Results are now available as a technical memorandum (see link below), and will be in peer reviewed literature and in non-technical summaries. These works developed a baseline assessment against which we can compare with future conditions and evaluate changes to the health of the study area. We hope to repeat this study in five and ten years to monitor the watershed.