energy and longshore currents are probably responsible for the distribu- 

 tional patterns of the nearshore fauna. 



5. Comparison of Abiotic and Biotic Parameters Between 1979-80 and 1974-75 . 



Temperature, salinity, sediment grain-size distribution, organic carbon, 

 gnd carbonate content showed little variation between 1979-80 and 1974-75. 

 The borjrow sites which were not sampled in 1974-75 showed similarities to 

 the control stations for these abiotic parameters. Apparently, the borrow 

 pits initially filled with fine sandy sediments including elevated levels of 

 silt-clay (Saloman, Naughton, and Taylor, in preparation, 1982). However, 

 based on current data the borrow pits have returned to a texture comparable 

 to surrounding areas. Moderate wave action and high longshore transport rates 

 (Balsillie, 1975) probably account for the rapid filling of the borrow pits. 



Although community parameters (namely, species richness, faunal density, 

 diversity, and equitability) indicate that most of the stations had a 

 different community composition in 1979-80 than in 1974-75, interpretation 

 of the data considering seasonal and spatial variations indicates that the 

 fauna of the area is drawn from a common pool of "available" species . There- 

 fore, the changes in community composition encountered in this study cannot 

 be attributed to beach nourishment activities. Seasonal variations are 

 known to be significant in most parts of the Gulf of Mexico and adjacent 

 estuarine waters (Livingston, 1976; Livingston, et al., 1976; Simon, 1977; 

 Mahadevan, et al., 1977; Culter, et al., 1981). 



6. Long-Term Effects of Beach Nourishment . 



Based on the data and findings of this study, it is concluded that the 

 beach nourishment program conducted during 1976 on the Panama City and 

 adjacent beaches has not manifested any long-term discernible effects on 

 the benthic infauna or the surface nearshore sediments. 



V. SUMMARY AND CONCLUSIONS 



A study of benthic macrofauna and sediments was conducted in the near- 

 shore zone of the area between West Pass and Philips Inlet at Panama City 

 Beach, Florida, in the northeastern Gulf of Mexico. Samples of surface sedi- 

 ments and fauna were collected from 28 November to 1 December 1979 and from 

 19 to 23 May 1980. Forty-seven stations, located on nine east-west transects, 

 and two dredged borrow sites were sampled. 



Temperature, salinity, and dissolved oxygen were measured at each 

 station and found to vary seasonally. There was very little spatial 

 variation of these parameters. Temperature ranged from 16.5 to 26.0 

 Celsius; salinity ranged from 29.0 to 35.5 parts per thousand; and dissolved 

 oxygen ranged from 4.8 to 8.6 parts per million. Substrata within the study 

 area consisted of fine to medium, coarse quartz sands, with very low levels 

 of silt-clay, percent organic carbon, and percent carbonate. The abiotic 

 parameters collected during this study were similar to Saloman 's (1976) 

 measurements. Sediment grain-size parameters were also generally comparable, 

 with the major differences occurring in percentages of silt-clay, organic 



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