FORT MYERS BEACH, Fla. — A five-year study led by Florida Gulf Coast University (FGCU) suggests that discharges from the Caloosahatchee River may not be the main cause of red tide along Estero Island. Instead, the study found that water quality around Fort Myers Beach varies mostly by where and when samples are taken, rather than by freshwater flowing from the river.
WATCH AS FORT MYERS BEACH COMMUNITY CORRESPONDENT ANVAR RUZIEV BREAKS DOWN THE DETAILS OF THE WATER STUDY:
Snapshot of Water Quality
FGCU students, staff, and local volunteers teamed up for a project they call “What’s in the Water?” They collected samples from 46 sites around Estero Island during low tide. Low tide was chosen so there would be less ocean water mixing in, giving a clearer picture of what’s happening near the shore.
“It’s really just to kind of take a snapshot around the island and see what water quality is on any given day,” explained Dr. Mike Parsons, a professor of Marine Science at FGCU’s Water School.
Researchers tested the water for:
- CDOM (colored dissolved organic matter), which gives water a tea-like color
- Turbidity, or cloudiness
- Chlorophyll A, an indicator of algae
- Salinity, to see how much fresh versus salt water is present
- Total nitrogen and phosphorus, two nutrients that can fuel algae growth
Key Findings
Dr. Parsons said the team did not see a strong link between freshwater from the Caloosahatchee River and higher nutrient levels around the island. “It’s not that the signal wasn’t really there,” he said. “It just wasn’t showing up or presenting itself in the way we analyzed or the way we designed the experiment.”
High levels of nutrients—like nitrogen and phosphorus—can sometimes lead to algae blooms, including red tide. However, the study’s data showed that local discharges were not clearly tied to spikes in nutrients or algae near the beach.
What Makes the Water Look Cloudy
According to Dr. Parsons, murky or cloudy water often comes from particles like sand being stirred up by wind or boat traffic.
“Many times in our near shore waters in the bay and things like that, it’s because of the sediment getting resuspended,” he said.
Algal blooms can also make water look cloudy, but most of the time, waves and boats play a bigger role.
Community Involvement
More than 50 people helped with the most recent round of testing. The Fort Myers Beach Chamber of Commerce Water Foundation and the National Oceanic and Atmospheric Administration (NOAA) provided funding for this citizen science project.
Dr. Parsons stated that the study did not receive funding from any corporations.
“This is a citizen science project where they’re engaged, they’re collecting the data, they’re interested, and looking at the results,” said Dr. Parsons. “The next step really is to see if we see some sites that might have poorer water quality than other sites and try to come up with some possible reasons.”
Based on the study, scientists say nitrogen may be the top nutrient to focus on for improving water quality.
The researchers also plan to install a new real-time water monitoring system on Fort Myers Beach to track changes day by day.
