By leveraging reserve capacity and deepening relationships, this project fostered connectedness between people and data to strengthen water quality restoration efforts in Guana River Estuary.

The Project The Guana River Estuary in northeast Florida is impacted by excess nutrients, regular occurrences of algal blooms, and a clear gradient of human influence from the headwaters to the estuary. In 2022, Florida Department of Environmental Protection determined that the Guana River Estuary headwaters, Guana Lake, and Guana River do not meet state water quality standards for nutrient concentrations.

Restoring shellfish populations in ecosystems like the Guana River Estuary, can help improve water quality, since shellfish like oysters and mussels naturally filter water and increase removal of excess nutrients. However, this approach requires that ecosystem managers have a better understanding of how nitrogen moves through their estuary and the capacities of shellfish communities to remove nitrogen (N). Key information gaps include the distribution of shellfish species, the efficacy of different shellfish for nutrient removal, and the effects that water quality may have on shellfish function. By leveraging a well-established collaborative group, GTM Reserve's Oyster and Water Quality Task Force, and engaging additional users, this project helped to fill these gaps and support more holistic water quality management efforts in and around the Guana River Estuary.

To assist with the development of restoration and management plans, this project:

1.Identified how land use change in the watershed affects the delivery of N to Guana Lake; 2. Surveyed shellfish distributions and condition; 3. Quantified filtration and N removal by shellfish; 4. Conducted field experiments to assess how N affects phytoplankton biomass and shellfish growth rates; and, 5. Quantified N removal via denitrification throughout the Guana River Estuary. The project not only generated valuable water quality and shellfish data but it also established a path for increased research and monitoring by fostering connectedness between people and data. The combination of robust data, open and transparent discussions, and regular check-ins increased trust in science, deepened relationships, and generated a number of products, including shellfish distribution maps, shellfish filtration and denitrification rates, sediment nutrient fluxes and denitrification rates along the salinity gradient, monitoring and restoration recommendations, and peer-reviewed and outreach publications. These outcomes will strengthen water quality restoration efforts in the Guana River Estuary and the greater watershed area.