FCE-LTER researchers expected fish species richness and biomass to be higher in the Shark River Slough/Gulf of Mexico ecotone than in the Taylor Slough/Florida Bay ecotone because primary production is higher in the Shark River Slough ecotone. Results, however, showed that the opposite was true. Scientists now believe that fish biomass is higher in the Taylor Slough ecotone because wetland-open water habitat connectivity is greater. This is thought to be due to differences in small-scale topographic relief and tidally-driven inundation regimes between the two ecotones. In the Shark River Slough ecotone, salt-tolerant species are dominant, while in the Taylor Slough ecotone, freshwater and salt-tolerant taxa are dominant depending on the season.
Researchers also examined the impacts of gradients in hydrology and nutrient availability on trophic, or food web, position of eastern mosquitofish (Gambusia holbrooki), riverine grass shrimp (Palaemonetes paludosus), and Florida gar (Lepisosteus platyrhincus). They found that local drying events decrease trophic position in mosquitofish and grass shrimp, but have no impact on gar because they avoid drying habitats. In other words, the number of species that feed on mosquitofish and grass shrimp is greater during dry conditions than during wet conditions.