Seagrasses are highly productive ecosystems. A before-after-control-impact (BACI) design was used to examine effects of dredging on seagrasses and the animals that inhabit them. The control site North Biscayne Bay (NBB) and impacted site Port of Miami (POM) had seagrass densities decreased during the before, Fish and Invertebrate Assessment Network (FIAN) 2006-2011 and after, Faunal Monitoring Due to Harbor Dredging (FMHD) 2014-2016 studies. Turbidity levels increased at NBB and POM basins during the FMHD study, especially in 2016. Animal populations decreased significantly in NBB and POM in the FMHD study compared to the FIAN study. If seagrass communities are not stabilized, animal numbers will likely continue to decrease. There could be impacts on several fisheries vital to the South Florida economy. Additional research could determine if animal populations and seagrass densities have rebounded or continued to decrease.