Ian storm surge changed Sanibel’s freshwater lake environments, bringing new algae concerns

SANIBEL – Like many things in Sanibel, after Hurricane Ian, the environment changed significantly. Ponds that once were freshwater before the storm, are now saltwater. That is due to the 8 to 14 feet of storm surge that occurred on Sanibel. And now, that change going back to freshwater could be a slow-go to reverse.

“I expect it to last 1 to 4 years depending on the pond,” said Dr. Serge Thomas with Florida Gulf Coast University’s Water School. Hurricane Ian’s storm surge changed these lakes and ponds in 24 hours' time.

“All the life that was in those lakes pretty much died off immediately,” said Mark Thompson, a research associate with the Sanibel Captiva Conservation Foundation. “We lost fish. We lost plants. We lost everything that depended on them to survive in our freshwater habitat.”

The changes in salinity are being studied separately by both SCCF and FGCU’s Water School. Both organizations are clear that these changes could cause algae blooms of all types over the next few years.

“We are going to get different kinds of algae blooms in our lakes that people haven’t seen before, just because they are in different habits than before,” said Thompson. “But, there is always going to be some kind of algae that wants to bloom no matter what kind of water you have in your system.”