CHANGES IN SEDIMENT ACCUMULATION ASSOCIATED WITH 1960S ANTHROPOGENIC DEVELOPMENT IN BOCA CIEGA BAY, TAMPA BAY FL 

Our study aimed at determining if a geologic signature from the dredge and fill associated with anthropogenic development could be detected in the sediment record and if these significant anthropogenic alterations affected the integrity of Boca Ciega Bay. Sediment cores were collected in Boca Ciega Bay to assess the impacts of anthropogenic development (1960’s) on sedimentation patterns and benthic environments. Throughout the 1960’s, dredging and filling occurred throughout Boca Ciega Bay to expedite development of coastal neighborhoods and accommodate Florida’s population boom. Over 15,000 acres of natural habitat were lost to this process, with construction, in particular bridges altering tidal flow/velocities and circulation patterns throughout lower Tampa Bay. Five sediment vibracores were collected throughout the bay in areas least likely to be disrupted by boating wakes and high energy waves, thereby increasing the probability of an undisturbed sedimentary record. Surface sediment grabs were collected at 13 sites to determine the current grain size to estimate currents/tidal velocities and circulation. Sediment records showed that the dredging and filling process initially altered the benthic environment from a lower energy environment to a seemingly higher one. However, once construction was completed, the environment shifted back to a lower energy environment, but did not fully recover. Our study reflects on dredge and fill procedures as coastal communities will continue to be developed and could witness changes in the future. From these results, maintaining Boca Ciega Bay water quality is necessary to maximize ecosystem services provided by this marine environment.