Suncoast Waterkeeper releases 2024 water quality report

Suncoast Waterkeeper recently published its 2024 year-end review in which the organization analyzed water quality data showing trends in the swimmable safety of water around the Suncoast. 

Of the 11 sampling sites around Manatee and Sarasota counties, the two on Longboat Key proved to have some of the highest percentages of swimmable weeks throughout 2024. 

Roughly 84% of the weeks in 2024 were safe to swim around the Longboat Key Boat Ramp on the north end of the island. Similarly, 80% of the weeks last year were safe to swim near Bayfront Park.

In comparison, areas further north like the Bridge Street Pier in Bradenton Beach and the Palma Sola Causeway had 48% and 45% of swimmable weeks, respectively. 

The report also detailed how storms had an impact on the water quality samples. All the sites performed poorly after Hurricane Debby, which was mainly a rainfall event.

Some sites could recover quicker after Hurricanes Helena and Milton because of less rainfall, but areas on Longboat Key had prolonged contamination likely because of storm surge bringing debris into the waterways. 

Suncoast Waterkeeper uses enterococci as a fecal matter indicator, which is the indicator used by agencies like the Florida Department of Health and the Florida Department of Environmental Protection.

“High enterococci levels can negatively affect human health and indicate fecal pollution from stormwater runoff, pets, wildlife and sewage,” the report states. 

Months with heavy rainfall tended to produce higher concentrations of enterococci in Suncoast Waterkeeper sampling sites. This is apparent during the summer months. 

Rainfall events any time of the year can trigger higher concentrations, said Suncoast Waterkeeper Executive Director Abbey Tyrna. 

“The rain carries with it everything that’s on our yards, any kind of animal fecal matter,” Tyrna said.

This was apparent at the end of February when Suncoast Waterkeeper’s results from Feb. 25 showed high concentrations across the board. 

Courtesy image

Measuring Enterococci concentration involves the amount of bacteria per 100 milliliters (mL) of water. Concentrations of 0-35 bacteria per mL are safe to swim, swimmers should take caution in 36-70 bacteria per mL and it’s not advisable to swim if the concentration is higher than 71 bacteria per mL. 

On Feb. 25, Longboat Key’s Bayfront Park had a reading of 96 bacteria per mL and the water near the Sarasota Sailing Squadron had 226 bacteria per mL. 

Rainfall occurred days before those samples, in some areas accumulating up to 2 inches, according to Tyrna. 

“That’s enough to trigger high levels of fecal indicator bacteria across the Suncoast," Tyrna said. 

Outside of rainy months, there are a few other reasons for higher enterococci readings, but one reason is the decomposition of plant matter. 

Warm-blooded animals primarily produce enterococci and Tyrna said the decomposition of some plant material can replicate the enterococci material. 

According to Tyrna, that’s why Longboat Key’s Bayfront Park may have higher readings when dead seagrass and mangrove roots accumulate in the park’s waters. 

“We will then find high levels of enterococci in those areas because of the decomposition that’s occurring,” Tyrna said. 

Risks and mitigation

Areas with high concentrations of enterococci can cause health hazards like disease, infections and rashes. 

Tyrna said it’s important for people to be mindful of the water quality in their favorite swimming locations by using data like that produced by Suncoast Waterkeeper. 

“My advice to people would be to take caution and to know what the water quality is like in the area where you like to swim,” Tyrna said. 

Additionally, Tyrna advised swimmers to avoid high-risk areas for 2-3 days after clearing conditions and, if anyone does get sick, to contact poison control to document cases. 

Going forward, Tyrna said the best mitigation strategy for municipalities would be to improve stormwater and wastewater systems. 

“We need better stormwater management in order to clean up the water before it enters our bay,” Tyrna said. “There are places where water enters our bay untreated.”

Tyrna added citizens should be more mindful of picking up pet waste from yards. On boats, she also said it’s important for moorings and boat owners to properly dispose of waste. 

“We have found (that) as a contribution to fecal indicator bacteria,” Tyrna said. “Allowing them to do that without having waste management around is a problem.”

For more information about Suncoast Waterkeeper and its weekly water quality monitoring, visit SuncoastWaterkeeper.org.