The pre-drainage Everglades (FL, USA) was a shallow slowly flowing wetland with a “corrugated ridge and slough” habitat mosaic. Drainage and compartmentalization in the 20th century reduced water levels and degraded the spatial patterning of the landscape. In some places, high densities of sawgrass (Cladium jamaicense) and cattails (Typha spp.) from the ridges have filled the historically deeper lily and spike rush sloughs and the microtopographic relief has been lost. Over three years we quantified densities of small fishes and large macroinvertebrates with 1-m2 enclosure traps in 12 degraded (sawgrass-filled) sloughs and 12 paired (adjacent) remnant sloughs within a 14 km2 area of contiguous wetland where most sloughs had been lost to sawgrass encroachment. We found higher densities of fish in the remnant sloughs than the degraded sloughs, but higher densities of crayfish and seasonally higher densities of insects in the degraded sloughs. In September 2023, sawgrass and cattails in 4 of the 12 degraded sloughs were treated with herbicide to re-establish slough-like habitats. We conducted Before-After Control-Impact analyses on the combined live stem density of sawgrass and cattails and the total biovolume of metaphytic microbial mats. We found that six months after spraying, the sawgrass and cattails in the impacted sites were dead, We also conducted similarity-based BACI-type analyses with PERMANOVA of the aquatic animal community similarity looking for compositional changes away from the degraded conditions over the four sample events post-spraying. We found no immediate treatment effect in the year following the application (2024), but observed some significant shifts in composition in 2025. Our results suggest the active marsh improvement efforts are having an effect on the aquatic animal community composition that should become more evident as slough vegetation grows and the sawgrass detritus fully decomposes.