State of the Slough Spring 2025

At the southern end of Everglades National Park, a series of sloughs convey fresh water to the Florida Bay estuary. Audubon researchers track these freshwater deliveries (or lack thereof) and their impacts on the ecology of Taylor Slough and the Bay.

Water year 2024-25 started off with higher-than-normal water levels in June but remained within the normal range until September, when water levels started to rise. Rainfall from Hurricanes Helene and Milton temporarily increased the water levels. Even with a steady decrease from mid-November, water levels never managed to reach below 13 cm by the end of January. Sea level rise is likely contributing to higher water levels, decreasing the likelihood of water levels ever reaching 13 cm in future years. Roseate Spoonbills need water levels to fall below 13
cm to effectively feed their growing chicks.

Historically, Taylor Slough was a freshwater ecosystem. Freshwater conditions persisted for most of this year, with salinity in the low-normal range at the beginning and end of the water year. Pulses of higher salinity occurred in September (an effect from Hurricane Helene) and in March, but both were temporary and we think had little impact on freshwater plant and fish communities. Overall, freshwater levels have been stable and consistent—something we need to see more of over the next couple of years to allow system recovery.

The average cover of plants for the end of water year 2024-25 (June through March) was 8.4%—a slight increase in coverage in comparison to the last decade. This region is still experiencing very low coverage, even though fresh water has been consistent. However, species such as Najas marina and Utricularia spp. have started to grow in the area, indicating that the system is on an upward trend right now. We will continue to follow this ongoing positive trend.

From June 2024 through March 2025, 833 fish were caught, with 412 of them classified as freshwater species, suggesting freshwater species represent 49% of the total annual fish community, which is a great improvement over recent reports! The fish community structures throughout the Southern Everglades (not just Taylor Slough) indicate how the ecosystem is responding to restoration efforts. In the Taylor Slough region, the community is currently comprised of 12.5% Mayan cichlids, an invasive species that negatively affects the native fish population. However, we think the positive response of freshwater species outshines the cichlids. Improving indicators of ecosystem health in Taylor Slough are due to a range of weather and restoration factors, including increasing water flow.

Download a PDF of this report. 

This article is an excerpt from the State of the Everglades Report/Spring 2025 edition