more than physiological, as foreign water masses would undoubtedly introduce 

 a variety of immigrant organisms and potential community recruits. 



A comparison of sediments from undredged bottom and borrow pits showed 

 that most deviations from normal properties appeared in experimental samples. 

 Major sedimentological differences could be identified due to accumulation of 

 loosely packed, darker, and siltier sediments in the pits shortly after dredging. 

 These distinctions became more subtle with time, and by the following year, the 

 surface samples (in nearly filled pits) were very similar to sediments on the 

 adjacent undisturbed sea floor. When compared to base-line samples, specific 

 differences included the following: (1) lower sand content, (2) higher silt- 

 clay content, (3) poorer sorting, (4) more finely skewed, (5) more variation 

 in both directions from a leptokurtic condition, and (6) higher content of 

 organic carbon. 



In the borrow pit at station 1, altered sediment texture was confirmed by 

 divers, and bathymetric changes were recorded over time. Depth of the cut was 

 3 to 5 meters below the sea floor, and sediment at the bottom initially appeared 

 dark, soft, and silty. Within a few months this material was covered by fine 

 sand. By the end of sampling in November 1977, the pit had filled to within a 

 meter of the surrounding bottom. A final visual impression was that sediments 

 were still finer and darker, but no distinction could be made between epibenthic 

 and pelagic marine life inside and outside the borrow pit. 



Dredging caused an immediate decline in the bottom community followed by a 

 rapid postconstruction recovery that was virtually complete after 1 year. This, 

 or even a shorter recovery period of 8 to 9 months, was supported by analyses 

 that included: (1) species richness, (2) abundance of individuals, (3) diversity 

 and equitability indexes, (4) Morisita's index of faunal similarity, and (5) 

 stability analyses. It is important to again note that sampling beyond 1 year 

 indicated lack of complete faunal recovery. This may be true, or these samples 

 may merely be representative of large natural environmental variations that 

 were shown to be an inherent characteristic of the shallow coastal system off 

 Panama City Beach. 



On the basis of data presented here, and complementary studies by Saloman 

 (1976) and Culter and Mahadevan (1982), it is evident that dredging done at 

 Panama City Beach has had no adverse long-term effect on bottom dwelling 

 invertebrates, sediments, or water quality either along the shore or in offshore 

 borrow areas. Short-term ecological consequences of dredging were shown to last 

 only about 1 year, and included only minor sedimentological changes and only a 

 small decline in diversity and abundance among bottom dwelling invertebrates. 

 This lack of evident protracted environmental alteration is due to factors 

 related to physical and biological oceanography within the dredging and disposal 

 areas, and to certain engineering features of the beach restoration project. The 

 natural factors would include the following regional characteristics: (1) moderate 

 to high wave energy capable of eroding and transporting large volumes of sediment 

 annually, (2) tidal, longshore, offshore, and storm generated currents that have 



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