August rains brought much-needed relief to Sanibel’s wetlands, but inland lakes remain stubbornly salty, according to the Sanibel-Captiva Conservation Foundation (SCCF). The dynamic nature of barrier islands like Sanibel means shifting salinities in its inland waterbodies, and while some areas have seen improvements, the effects of past storm surges are still being felt.
Heavy rains in August have rejuvenated shallow, brackish pools, providing a fresh environment for native frogs and toads to reproduce and disperse. “The heavy rainstorm on August 10, which brought nearly 12 inches of rain in just over 13 hours, flooded out brackish pools, improving our freshwater areas,” said Chris Lechowicz, SCCF’s Wildlife & Habitat Management Director.
As a result, species like marsh crayfish, southern leopard frogs, and Florida softshell turtles, previously struggling to find suitable habitats, are now able to return to these revitalized areas. Lechowicz explains, “Longer gaps between surge events will help wildlife populations rebuild and restore food webs and ecosystem balance.”
However, deeper, more permanent waterbodies on the island—such as the Sanibel Slough, Devitt Pond, and Gulf Ridge Marsh—continue to hold higher salinities, a lasting effect of recent hurricane surges. These areas have seen significant vegetation loss, particularly buttonwood trees and other hardwoods, which couldn’t survive in the salty waters.
Sanibel’s man-made lakes, created during the 1970s and 80s as part of residential developments, also remain salty. These lakes, originally filled with freshwater, were heavily impacted by the storm surge events, exchanging their freshwater for salty Gulf and Bay waters. Mark Thompson, SCCF Marine Lab Research Associate, notes that these lakes, such as Murex Lakes and Palm Lake, have slow freshwater recharge rates and remain highly saline, despite the August rains.
While the wetland areas are slowly recovering, Thompson adds, “It may take years for these larger lakes to support freshwater vegetation and wildlife again.”
