SANIBEL, Fla. — A little over two years ago hurricane Ian swept through Southwest Florida covering the island of Sanibel with storm surge. Not only causing damage but turning freshwater ecosystems into saltwater ones.
Just a couple of months ago, we had Helene and Milton doing the same thing. But what does that mean for the long term of Sanibel. Fox 4 Meteorologist Andrew Shipley spoke to Sanibel Captiva Conservation Foundation (SCCF) about just that.
The last real storm surge event, which was even as bad as Ian, was in 1947,” said Chris Lechowicz, SCCF’s Wildlife and Habitat Management Program Director.
And now the island of Sanibel has been covered in salty storm surge not once, but four times in the last 2 years (Ian, Debbie, Helene, and Milton). And that is changing not only what lives on Sanibel, but the ecosystem itself.
“And a lot these trees that have grown up over the last few decades are just not salt tolerant,” said Lechowicz. “So, we had a lot of tree death.”
The surge didn’t just cause tree mortality, but also changes to freshwater ecosystems like Sanibel Slough. After Ian, it took nearly two years of rainfall for the slough to return to a freshwater state.
“Now that we have two more storm surge events, salinities are through the roof again,” said Lechowicz. “It’s basically salt water everywhere."
Take a look at this chart. You can see the low salinity leading up to Hurricane Ian then the spike in saltwater followed the slow decline since.
Fast forward to this year, we finally return to normal levels in June. But after Debbie we saw another spike up, but recovered quickly from heavy rainfall. But then came Helene and Milton.
Lechowicz says if this trend continues, Sanibel could return to it’s historical roots.
“If this trend continues, what you end up with is what Sanibel was historically, mostly a grassland,” said Lechowicz. “If you were here prior to 1960, a lot of the island was mostly grass.”
With climate change and sea level rise, more saltwater intrusion events will become more likely on Sanibel in the future. Lechowicz says that means species that rely on freshwater are going to have a hard time.
“It’s possible that some animals that do better in brackish water extend their ranges on the island and ones that need pure freshwater might not make it,” said Lechowicz.
