NOAA funds FAU study of persistent harmful algal blooms

Florida Atlantic University researchers have received a $1.3 million grant to investigate why harmful algal blooms persist in Florida’s Northern Indian River Lagoon but remain comparatively short-lived and moderate in Georgia’s Skidaway River Estuary. The award from the National Oceanic and Atmospheric Administration’s National Centers for Coastal Ocean Science supports a research project examining the environmental and biological mechanisms associated with recurring blooms in two subtropical estuaries. It is a planned study rather than a report of completed experiments or a demonstration that a particular management approach will work.

The project, funded through NOAA’s Fiscal Year 2026 Harmful Algal Bloom Program, is led by Mingshun Jiang, an associate research professor at FAU Harbor Branch Oceanographic Institute. Researchers from Florida Atlantic University, the University of Georgia and the University of South Florida are joining the effort. Their disciplinary backgrounds include physical oceanography, biogeochemistry, plankton ecology, environmental management and modeling. The team’s objective is to connect observations of the two estuaries with biological processes that may explain why certain algal species thrive and dominate in one system but not to the same extent in the other.

The Northern Indian River Lagoon is designated an “Estuary of National Significance” and is estimated to provide $28.3 billion in annual economic benefits. The source announcement says the lagoon experiences frequent and persistent harmful algal blooms that degrade water quality, contribute to extensive loss of seagrass and cause major mortality events for fish. These are reported conditions in the lagoon, not outcomes of the newly funded project. By contrast, the Skidaway River Estuary is described as a similarly shallow and warm subtropical system but does not experience the same prolonged blooms. Stronger tidal flushing and a shorter water residence time create a different environmental setting for the Georgia estuary.

That geographic contrast provides the central research opportunity. The investigators plan to examine how water residence time, nutrient availability, temperature, organic matter, sediment processes and interactions among organisms influence bloom dynamics and the algal species present. They will not treat any one factor as a settled explanation. Instead, the planned work will test which combinations of physical conditions, chemical conditions and biological interactions are associated with blooms that persist in the Northern Indian River Lagoon and blooms that are comparatively short-lived in the Skidaway River Estuary.

Field observations will supply the environmental record for the comparison. Researchers will conduct extensive fieldwork at both estuaries and track temperature, salinity, nutrients, organic matter, bloom abundance and species composition. The measurements are intended to document the conditions under which bloom-forming algae occur and how those conditions differ between the systems. Observations from the natural estuaries will also provide the foundation for laboratory and in-water experiments and for the physical-biogeochemical modeling component of the project.

Laboratory and in-water experiments will focus in part on how algal communities respond to changes in nutrients. The work will examine three representative bloom-forming species: Akashiwo sanguinea, Aureoumbra lagunensis and Pyrodinium bahamense. University of Georgia co-principal investigator Natalie Cohen will lead this part of the project. By placing controlled manipulations alongside field observations, the researchers plan to evaluate how these species and the wider algal community respond under different nutrient conditions and to test biological explanations for their abundance, dominance and persistence.

Sediment sampling will form another component of the investigation. FAU Harbor Branch co-principal investigator Jordon Beckler will lead the collection of sediment samples and associated biogeochemical information. The team will use these data to investigate nutrient fluxes from the sediment, which the source announcement identifies as a possible key source for sustained phytoplankton blooms in these estuaries. The study will assess sediment processes in the context of the broader field measurements, experiments and models rather than treating sediment dynamics as a predetermined cause of the difference between the two lagoons.

The team will also further develop an existing physical-biogeochemical model of the Northern Indian River Lagoon and adapt it for the Skidaway River Estuary. The paired models will be used to compare how the systems respond to environmental conditions and to identify factors that may account for persistent blooms in Florida and comparatively short-lived blooms in Georgia. According to the award announcement, the results are intended to refine predictive models that can help resource managers evaluate mitigation strategies and issue early warnings of harmful algal blooms in other subtropical estuaries across the Southeast. Those are prospective uses that depend on the findings of the research.

The project also has approximately $200,000 in new support from the Harbor Branch Oceanographic Institute Foundation, Inc. That funding will support Jiang, Beckler and Malcolm McFarland, an assistant professor at FAU Harbor Branch whose research includes the life cycle of P. bahamense. The additional support complements the NOAA award by providing resources for work on that species while the broader project examines environmental conditions, community responses, sediment biogeochemistry and bloom behavior across the two estuaries.

University of South Florida co-principal investigator Charles Jacoby, co-director of the Center for Environmental Analysis, Synthesis, and Application, is also part of the multidisciplinary team. FAU Harbor Branch interim executive director Jason Hallstrom said the grant recognizes the need to bring together scientists with different areas of expertise to address a complex environmental challenge. The announcement says the knowledge generated will have immediate relevance to the Northern Indian River Lagoon and its dependent communities, as well as broader potential value for subtropical estuaries elsewhere in the Southeast. The project combines field sampling, experiments, sediment analysis and computational modeling, and its predictions, management applications and early-warning benefits remain to be established through the research.

Subject of Research: NOAA-funded investigation of environmental and biological drivers of persistent harmful algal blooms in two subtropical estuaries

Article Title: FAU receives $1.3M NOAA grant to address harmful algal blooms

Article References: FAU receives $1.3M NOAA grant to address harmful algal blooms. Original publication (Bibliographic details unavailable.)

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Keywords: harmful algal blooms, NOAA, Florida Atlantic University, Northern Indian River Lagoon, Skidaway River Estuary, subtropical estuaries, plankton ecology, nutrient availability, sediment biogeochemistry, estuarine modeling, water residence time, field experiments