Hess, D. .
1995.
A Study of Storm and Anthropogenic Effects on Estuarine Sedimentation, Apalachicola Bay, Florida..
Geology. Tallahassee, Florida State University.
Estuaries are influenced by the interaction of fluvial, tidal, oceanographic and climatic processes. A minor change in anyone of these agents can have a significant impact on the entire estuarine system. These sensitive environments are also highly productive. Apalachicola Bay, Florida, is an important nursery for both commercial and recreational fisheries. The majority of the employment within the surrounding counties (Franklin and Gulf) is directly related to the estuary. .Continued non-regulated development within the watershed of the Apalachicola-Chattahoochee-Flint Rivers, the catchment of Apalachicola Bay, has the potential for adverse effects within the estuary. Deterloratlon of the estuary's health would have a devastating effect in the surrounding counties. Defining the recent (100-150 yr) sedimentation history for Apalachicola Bay increases our understanding of the processes acting upon the bay. The Pb-210 dating method yields accurate sedimentation rates for the past 100-150 years, providing a structure for such a history. Analysis of a suite of sediment cores from Apalachicola Bay yields evidence that sedimentation rates have generally been constant and uninterrupted for the past 100-150 years. This finding conflicts with previous studies which concluded that major storms produce significant hiatuses in the sedimentation record of the estuary. The current study shows no major sedimentologic events occurring within the past 100-150 years, thus suggesting that storms have had little effect on the sedimentation history of Apalachicola Bay. Textural analysis (sand-silt-clay percentages) show that the granulometry of the sediments being deposited within the estuary has changed over two periods in the estuary's recent history. However, neither one of these changes corresponds to the time when extensive dam construction began along the Apalachicola-Chattahoochee-Flint river system in the early 1950s. This finding also contradicts previous studies which suggest that, since the construction of the dams, the relative abundance of sand reaching the estuary has increased while the amount of silt has decreased. Overall, the recent history of the Apalachicola Bay Estuary reveals little change in sedimentation over time.