New nutrient sensor in the Caloosahatchee helps researchers protect SWFL waterways

A new underwater nutrient sensor between the Caloosahatchee and the Gulf of Mexico promises to help researchers solve some water issues facing Southwest Florida.

At the mouth of the Caloosahatchee, near Shell Point, researchers from the Sanibel Captiva Conservation Foundation dove into research. To get data, they sent out an autonomous nutrient sensor named Wiz beneath the surface.

“In an ideal world, we want basically no nutrients in the water. Nutrients, especially near shore, cause problems with algae blooms,” said AJ Martignette, a marine lab manager for SCCF.

Martignette said nutrients don’t cause algal blooms or red tide, but they’re proven to feed their growth.

The Wiz

The device is rigged to a piling underwater and pulls water samples out every two hours.

“We can’t be out there sampling 24 hours a day, seven days a week, but an instrument like this, that does all the chemistry and everything internally, will allow us to get that necessary information at the timescales that we need to build models and make predictions,” said Eric Milbrandt, the director of the marine laboratory with SCCF.

Milbrandt said we are always trying to figure out and improve the waterways in Southwest Florida. By itself, the Wiz only reveals the water’s nutrient levels. However, if you add SCCF’s many recon sites, you start to see the bigger picture of how local water input, as well as flows further up the river, work together to influence blooms.

Recon sites

“So we put this at our existing Shell Point recon site, and that site measures temperature, salinity, dissolved oxygen,” said Martignette.

“We can see on our other recon sites, either the start of an algae bloom or if our blue-green algae is increasing,” said Isabella McDonnell, a research assistant for SCCF. “And then if we compare that with a big influx of nitrogen, then we can kind of find a correlation there.”

The Wiz’s ability to pull data at any time means more information to model our water, make predictions and hopefully allow us to improve preparations in the future.

The nutrient sensors are taken every 30 days to get serviced and recalibrated. This is SCCF’s only nutrient sensory after some were lost to Hurricane Ian, but they plan to get another one going in the next couple of months.