The Cape San Blas Ecological Study Item Type monograph Authors Lamont, Margaret M.; Percival, H. Franklin; Pearlstine, Leonard G.; Colwell, Sheila V.; Kitchens, Wiley M.; Carthy, Raymond R. Publisher Florida Cooperative Fish and Wildlife Research Unit , University of Florida Download date 08/10/2021 14:45:26 Link to Item http://hdl.handle.net/1834/18974 The Cape San BIas Ecological Study Margaret M. Lall10nt H. Franklin Percival Leonard G. Pearlstine Sheila V. Colwell Wiley M. Kitchens and RaYll10nd R. Carthy ACKNOWLEDGMENTS Thisresearch would not havebeen possible withoutthe assistance of manypeople to whomwe are grateful. Support for all aspectsof this studywas received fromthe Natural Resources Division ofEglin Air ForceBase at Jackson Guard, specifically Rick McWhite, CarlPetrick, BruceHagedorn, Dennis Teague, andDebby Atencio. In addition, we are indebted to personnel at Tracer Corporation on Cape SanBIas, particularly Don Lawley, JudyWatts,Billy Suber, Mark Collier, CarlFox, O.P. Roney, Billy Griffen, andDeWayne Strader. Support fromDebraHughes, BarbaraFesler, and Caprice McRaeat the University ofFloridawas also invaluable and is greatly appreciated. The dedication and flexibility ofour field technicians, DaveHuetter,Eric Egensteiner, GregAltman, Shawn Diddie, MelindaSchaetbauer, Kris Fair, and Martha Maglothin madethis projectsuccessful and enjoyable. In addition, we thank Michael CookandJohn Stenberg for assistance with topographical and vegetation surveys and various GPS questions; special thanks to Lisa Ojanenfor her assistance and patiencewith the GIS portion of this project. We are alsograteful to Rick West for providing information and suggestions about neotropical migrant and shorebird sampling. For their willingness to assistand sharedata,we thankthe seaturtle volunteers along the St. JosephPeninsula andrangers withinthe St. Joseph StatePark. We also received valuable information regarding tropical storms fromRalphClarkat the FloridaDepartment of NaturalResources, Division of Beaches and Shores. In addition, we thank Jeff Gore at the FloridaGame and Fish Commission, PanamaCityfor assistance and adviceregarding several aspects of this study. TABLE OF CONTENTS ACKNOWLEDGEMENTS EXECUTIVE SUMMARY IV CHAPTER 1. EROSION Introduction 1 Methods 4 Results 5 Discussion 9 Management Recommendations 24 CHAPTER 2. LANDFORM AND LAND COVER CHANGE Introduction 48 Methods 48 Results 51 Discussion 51 CHAPTER 3. HYDROLOGY Introduction 61 Methods 62 Results 63 Discussion 64 Management Recommendations 68 CHAPTER 4. SOILS Introduction 84 Methods 84 Results 86 Discussion 88 Descriptions ofsoils sampled 98 CHAPTER 5. SHOREBIRDS, SEABIRDS, AND WADING BIRDS Introduction 118 Methods 120 Results 121 Discussion 128 Conclusions 141 Management Recommendations 144 CHAPTER 6. BEACH MICE Introduction 162 Methods 163 Results 163 Discussion 163 Management Recommendations 169 ii CHAPTER 7. NEOTROPICAL MIGRANTS - Introduction 174 Methods 175 Results 175 Discussion 177 Management Recommendations 184 CHAPTER 8. STORMS Introduction 195 Storm history 198 APPENDIX 207 iii EXECUTIVE SUMMARY Introduction The mainreservation of EglinAir Force Base (EAFB) is located on approximately 200,000 acres in Santa Rosa, Walton, and OkaloosaCounties, Florida. A variety of natural resources are found throughout this area, including species ofspecial concern such as BlackBears (Ursus americanus), Eastern Indigo Snakes (Drymarchon corais), Red­ cockaded Woodpeckers(Picoides borealis), and stands oflongleafpine (Pinus palustris). Through cooperativeresearch, EAFB has successfully managed these resources while also completing military missions. EglinAFB also owns several areas outside the main reservationthat provide support for military missions. One such area is located on Cape San BIasin Gulf County, Florida(Fig. 1). To properlymanagethis area, EAFB contracted the University ofFloridato completea three year characterization ofthe resources located along Cape SanBIas. Eglin AFB on Cape SanBIasconsistsof approximately 250 acres located about 180 miles east ofthe mainEglinreservation. This area lies on the S1. Joseph peninsula, part ofa dynamic barrier island chainthat extendsacrossthe northern GulfofMexico. Due to the natural forces that formed Cape SanBIasand those that maintain this area, St. Joseph Peninsula has experienced severelandform changeover time (see GIS landform changemaps). These changes allowfor fluctuations in habitattypes along Cape San BIas (see GIS land cover changemaps)that influence the floral and faunal species usingthis area. IV The dynamic environment along Cape SanBIasincludes flatwoods, interdunal swale, rosemary scrub, and beachfront. These habitats support a wide array of species, including several threatened and endangered species such as the loggerhead sea turtle (Caretta caretta), PipingPlover (Charadnus melodus), Least Tern (Sterna antillarum), and Bald Eagle (Haliaeetus leucocephalus). Proper management of these species and their habitatsrequire knowledge of their abundance and distribution, and the effects disturbances have on their survival. In addition to threatened and endangered flora and fauna, Cape SanBIas also supports tourists and recreationists. Although Gulf Countyis sparsely populated,with approximately 13;000inhabitants throughout 578 squaremiles, summer tourism and heavy recreational use ofbeachesfor fishing, crabbing, and shelling placecontinued and increasing pressure on the naturalresourcesofthese areas (Rupert 1991). GulfCounty is also one ofthe few remaining countiesin Floridathat permitsvehicular traffic on its beaches, including Cape SanBias. In addition to recreational use ofthese habitats;EAFB alsouses the area for military missions. AirForce propertyon Cape SanBIasis primarily used for radar tracking offlying missions over the GulfofMexico, althoughin recent years it has been used for missile launchings and other variousmilitary activities. To allowcontinued military and public use ofAirForce property whilealso protectingthe uniqueflora and fauna of the area, EAFBproposed a characterization ofthe resources found along Cape SanBIas. A complete inventory ofthe physical features ofthe area included investigating topography, soilchemistry, hydrology, archeology, and the v dynamics oflandmass and land coverchange over time. Various thematic layers within a geographic information system (GIS) were used to spatially portraygeoreferenced data. Large scalechanges over timewere assessed using stereo aerial photography. Vegetation transects, soil samples, elevation transects, an archeological survey, freshwater wells, and a tidalmonitorwere usedto investigate the remaining features. The distribution ofselected faunal species, suchas shorebirds, seabirds, wading birds, neotropical migrants, seaturtles, and beachmice, were correlated to these physical features andto vegetation. Surveys for shorebirds, seabirds, and wading birdswere conducted throughoutthe year alongthe cape point,whereas nesting sea turtles were monitored fromMay throughOctober, pointcountsforneotropical migrants were conducted during spring and fall migration, andtraps for beachmice were set duringone week in winter. Historical data was also collected on stormeventsand fires. Finally, an extensive literature searchand synthesis was completed. Comprehensive investigation ofthis area allows forunderstanding ofthe relationships among factors influencing Cape SanBIas. Each aspect of the environment influences the entiresystem, therefore allaspects mustbe researched before successful management is possible. A complete investigation ofthe forces forming and maintaining Cape SanBIas, the system providing protection and nourishment to its habitats, the species usingthose habitats, and the endangered species relying on the habitats for survival was conducted to allowdetailed, successful management ofthis unique and dynamic barrierisland. VI The sea turtle researchalongCape SanBIasthat was initiated at the beginning of this study is being compiled as a separatefinal report and is referenced withinthis text. In addition, informal observations of events or species not originally included in our objectives were recorded and compiled as field notes. Information on these observations are included as appendices at the end of the final report. Discussion The features and dynamics of Cape SanBIas are determined primarily by the formation and maintenance of this barrierisland. Its locationnear the mouth of a major river and the direction oflongshore drift alongthe coast influence the pattern of coastal changeand the habitattypes that regulatewhat resourceswillflourish along Cape San BIas. The Apalachicola River, approximately 20 miles east ofCape San BIas, has provided most ofthe sand to this sectionof the Floridapanhandle coast. The quartz sandsbrought by the Apalachicola Riverhavebeen reworkedand redistributed through longshoredrift and wave action (Johnson and Barbour 1990). The coarsest sandsare dropped offshore creatingshoals, whereasfiner sandsare carriedin the current and dropped alongthe beaches. Many of the barrierislands alongthe northernGulf ofMexico coast, including Cape San BIas, were created during the rise in sea level as these fine sandsbuiltover former nearshore deposits(see erosionchapter). The formation ofCape SanBIas in this manner assisted in determining the habitat types, and flora and fauna that now inhabit the region. Due to the great amounts ofsandin VII. the soils and the lack ofsaltwater intrusion into the surficial water table alongCape San BIas