Using Spectroscopy to Analyze the Wastewater Fingerprint in Biscayne Bay

At the upcoming American Chemical Society (ACS) Fall 2026 Meeting, which will take place from August 23^rd to the 27^th at the McCormick Place Convention Center in Chicago, Illinois, there will be several dedicated talks on how spectroscopy is being used to solve some of the world’s most pressing environmental problems.¹

One of these talks will focus on using fluorescence spectroscopy to monitor contaminants in Biscayne Bay, which is a subtropical lagoon stretching roughly 35 miles along Florida's southeastern coast, bordered by Miami-Dade County's urban core to the west and a chain of barrier islands to the east.²

This talk, titled, “High-frequency Monitoring Buoys and Optical Proxies for Enhanced Water Quality Assessment in Biscayne Bay,” will be delivered by Maria Guerra de Navarro of Florida International University.³ In her talk, she will discuss how high-frequency monitoring buoys deployed across Biscayne Bay are detecting chemical signatures linking degraded water quality to wastewater inputs.³

Her study, conducted by FIU's Center for Aquatic Chemistry and Environment (CREST), used buoys recording data every 15 minutes to track fluorescent and chromophoric dissolved organic matter, chlorophyll, and water flow throughout the bay's tributaries and coastal waters.³ Guerra de Navarro and the team paired this continuous stream with discrete water samples collected at 20 sites over 10 sampling events between September 2024 and May 2025, spanning both dry and wet seasons.³

What are the main environmental issues Biscayne Bay is experiencing?

Biscayne Bay is an important ecosystem that supports extensive seagrass meadows, mangrove shorelines, and coral patch reefs that serve as nursery habitat for fish, shellfish, and wading birds, making it one of the most ecologically significant estuaries in South Florida.² A large southern portion of the bay falls within Biscayne National Park, established in 1980 and encompassing roughly 173,000 acres, more than 95 percent of which is open water.⁴

The park protects a rare combination of ecosystems, including mangrove forest, the bay itself, the northernmost living coral reef tract in the continental United States, and a scattering of undeveloped keys.⁴ However, despite this protected status, the broader bay faces mounting pressure from urban runoff, wastewater infrastructure, and nutrient loading originating from the densely populated watershed upstream, which is why sustained water quality monitoring, like the buoy network FIU researchers described, has become central to managing the ecosystem's long-term health.^2–4

Why should environmental scientists and spectroscopists attend this talk?

Biscayne Bay has faced recurring water quality problems, including algal blooms and fish kills tied to nutrient pollution. Regulatory monitoring has traditionally relied on periodic grab samples, which can miss short-term pollution events.³ The FIU team's approach is designed to close that gap, and that’s why their study, while it investigated Biscayne Bay, can potentially have implications for other estuaries and water ecosystems.

Using mass spectrometry (MS) and fluorescence spectroscopy, researchers found strong positive correlations among nutrients such as total nitrogen, total phosphorus, and ammonia, alongside organic carbon markers.³ This pattern suggests these contaminants share a common watershed origin.

One of the key findings in the study was that sucralose, which is commonly used as a wastewater tracer, correlated positively with salinity-related measures and negatively with dissolved oxygen.³ Guerra de Navarro will explain in her talk how this pattern links wastewater discharges directly to oxygen depletion, which is a condition harmful to marine life.³

Another important takeaway from this research is the validation of fluorescent dissolved organic matter (fDOM) as a reliable, real-time proxy for broader organic matter dynamics when benchmarked against laboratory-based fluorescence analysis.³ Derived indices distinguishing labile from more resistant organic material could allow water managers to flag pollution events as they happen, which has numerous implications for environmental scientists and public policy.

For more information about the upcoming conference, you can visit the ACS website.

References

1. Wetzel, W. Why Spectroscopists Should Attend the ACS Fall 2026 Conference. Spectroscopy Online, 2026. https://www.spectroscopyonline.com/view/why-spectroscopists-should-attend-the-acs-fall-2026-conference (accessed July 14, 2026).
2. Miami–Dad County, About Biscayne Bay. Miami-Dade County Government Website, 2026. https://www.miamidade.gov/global/environment/biscayne-bay/about.page (accessed July 15, 2026).
3. Guerra de Navarro, M. High-frequency Monitoring Buoys and Optical Proxies for Enhanced Water Quality Assessment in Biscayne Bay. Presented at the American Chemical Society Fall 2026 Meeting, Chicago, Illinois, August 24, 2026. Available at: https://acs.digitellinc.com/live/37/page/1374?search=spectroscopy&tags=475&page=59&window-jn2mj2&window-w33qsi
4. National Park Service, Biscayne National Park. National Park Service, 2026. Available at: https://www.nps.gov/bisc/index.htm (accessed July 15, 2026).