Study Maps How Long Pollutants Linger in Northern Indian River Lagoon

New peer-reviewed research reveals that water in portions of the northern Indian River Lagoon — the estuary stretching along Indian River County's coastline — can stagnate for extended periods, a finding with serious implications for the toxic algae blooms and fish kills that have plagued Treasure Coast communities in recent years.

The study, published in the journal Estuaries and Coasts in 2023, used computer modeling to calculate "water residence time" — how long a parcel of water, and any pollutants or nutrients it carries, remains trapped in a given section of the lagoon before flushing out. Longer residence times allow nitrogen and phosphorus from fertilizer runoff, septic tanks and stormwater to accumulate, feeding the harmful algae blooms that have repeatedly closed beaches, killed manatees and seagrass, and alarmed residents in Indian River, St. Lucie and Martin counties, according to the study by Jiang M. et al., published in Estuaries and Coasts in 2023.

The research also examined "connectivity" — how well different sections of the lagoon exchange water with one another and with the Atlantic Ocean through inlets. Poor connectivity effectively isolates portions of the waterway, compounding the residence time problem and creating dead zones where water quality deteriorates rapidly.

The findings carry direct relevance for Indian River County, where the lagoon has experienced devastating seagrass die-offs and recurring "superbloom" events tied to nutrient overload. Understanding precisely where water moves slowly could help county officials and the St. Lucie County Health Department prioritize pollution reduction efforts and target restoration funding where it will have the greatest impact.

The full methodology is accessible via the journal's DOI. According to available information,

Researchers identified the lead author's institution as a potential contact for comment. The TC Sentinel has reached out and will update this report upon response. Residents concerned about current lagoon water quality conditions can monitor advisories through the Indian River County Health Department and the Florida Department of Environmental Protection's online water quality dashboard.

This article was generated with AI assistance using publicly available information. It was reviewed and approved by a human editor before publication. TC Sentinel uses AI writing tools in accordance with FTC guidelines.