LEE COUNTY, Fla. — The Sanibel Captiva Conservation foundation has been monitoring 30 lakes every month and evaluating the water quality in the Sanibel Slough since Hurricane Ian rearranged the habitats.
Before Hurricane Ian, the lakes on Sanibel were populated primarily
by freshwater plants and fish. Once the storm surge hit most of the freshwater fish died because they could not handle the increase in salt the storm brought.
Before Ian, the SCCF monitored around 80 lakes gaining substantial data.
In October the saltwater range was 20-33 practical salinity units. The goal level for freshwater is to have a salt intake range of 0-1.5 PSU.
SCCF Research Associate Mark Thompson said the more rain we get the more salt will gradually reduce. However, Florida is currently in the dry season and freshwater inputs to lakes are reduced during this time period.
It is not possible to restock the lakes with native freshwater fish in the water's current condition because of the animal's intolerance to salt.
“When we looked at the rate of salinity decrease since the storm surge, we estimate it may be at least next summer until salinities are low enough that native freshwater fish could survive again,” said Thompson.
However, it could be longer.
Some species of fish can survive in a larger range of salt intake while others cannot. The lakes will start to naturally restock with species that can tolerate salt over the next few months.
The salt intake in Sanibel's lakes is staying near sea water levels and will not decrease until the groundwater is recharged with fresh water.
