Skip to main content


Log in

Shallow Water Estuarine Mapping in High-Tide-Range Environments: a Case Study from Georgia, USA

  • Special Issue: Shallow Water Mapping
  • Published:
Estuaries and Coasts Aims and scope Submit manuscript


Efficient methods for shallow water data collection have been employed to create comprehensive bathymetric surfaces for 3 Georgia sounds. Survey areas were characterized using existing charted depths, aerial photographs, and lidar-derived elevation data to identify regions shallower than 3-m mean lower low water. Single-beam sonar missions were completed for these shallow areas using various marine platforms to constrain the existing 3-m isobath. Below 3 m, waters are deep enough, and swath width is wide enough, to use a larger vessel with an interferometric sonar system collecting swath bathymetry and sidescan imagery. The collected data were merged and gridded in a geographic information system environment to generate digital elevation models. The modern digital surfaces were compared with historic depth data to identify areas of shoaling and deepening. The mean overall change between the historic data and modern data was relatively small (0.7 m for Wassaw Sound, 0.4 m for Ossabaw Sound, and 0.1 m for Sapelo Sound); only the change in Wassaw was greater than the error in the analysis. However, each sound exhibited up to 20 m of shoaling and deepening associated with entrance channel migration, illustrating that a significant change occurs in specific geomorphic zones in each of these settings. Sediment grabs ground-truth sidescan sonar imagery to interpret environmental energy and bottom character. The mean sediment size for all sounds fell in the fine to very fine sand range (2–4 phi), reflecting the characteristics of the coastal sediment prism, although gravels and muds characterize areas of scour and quiescent conditions, respectively. These surveys led to the first identification of hard-bottom habitats of erosion-resistant, vertical cliffs up to 10 m high and 1000 m long in Southeastern US estuaries.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12

Similar content being viewed by others


  • Alexander, C. 2014. Improving habitat classification, hazard mitigation and navigation in coastal Georgia with a state-of-the-art bathymetric sonar system (Wassaw Sound). Brunswick, GA: Final Report to the Georgia Department of Natural Resources.

  • Alexander, C. 2017. Improving habitat classification hazard mitigation and navigation in coastal Georgia with a state-of-the-art bathymetric sonar system – Phase II (Ossabaw Sound). Brunswick, GA: Final Report to the Georgia Department of Natural Resources.

  • Alexander, C. 2019. Improving habitat classification hazard mitigation and navigation in coastal Georgia with a state-of-the-art bathymetric sonar system – Phase III (Sapelo Sound). Brunswick, GA: Final Report to the Georgia Department of Natural Resources.

  • Alexander, C. 2021. Artificial reefs essential and critical habitat, and bathymetry in Georgia coastal waters – Phase II (Year 2). Brunswick, GA: Annual report to Georgia Department of Natural Resources.

  • Alexander, C., J.E. Eckman, V.J. Henry, and R.L. Marinelli. 1997. Benthic characterization of Wassaw Sound: Detailed analysis. Georgia Brunswick, GA: Department of Natural Resources Coastal Resources Division. Contribution Series No. 58.

  • Alexander, C., M. Robinson, and C. Venherm. 2018. Unexpected bathymetry and habitat features in estuarine and inlet environments of Georgia, USA. American Geophysical Union Fall Meeting, December 10–14, 2018, Washington, DC.

  • Alexander, C., C. Venherm, and M. Robinson. 2020. Geospatial sediment assessment for Georgia estuarine, coastal and shelf environments. In Review of scientific research in and around the designated research area of Gray’s Reef National Marine Sanctuary (NW Atlantic), eds. K.W. Roberson, P.J. Auster, S. Fangman, and M. Harvey, 150–156. Silver Spring, MD: Marine Sanctuaries Conservation Series ONMS-20–08. U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Office of National Marine Sanctuaries.

  • Baine, M. 2001. Artificial reefs: A review of their design application management and performance. Ocean and Coastal Management 44: 241–259.

    Article  Google Scholar 

  • Basu, A., and N.K. Saxena. 1999. A review of shallow-water mapping systems. Marine Geodesy 22 (4): 249–257.

    Article  Google Scholar 

  • Becker, M., K. Schrottke, A. Bartholomä, V. Ernstsen, C. Winter, and D. Hebbeln. 2013. Formation and entrainment of fluid mud layers in troughs of subtidal dunes in an estuarine turbidity zone. Journal of Geophysical Research-Oceans 118: 2175–2187.

    Article  Google Scholar 

  • Blake, A.C., G.C. Kineke, T.G. Milligan, and C. Alexander. 2001. Sediment trapping and transport in the ACE basin South Carolina. Estuaries 24: 721–733.

    Article  Google Scholar 

  • Caballero, I., and R.P. Stumpf. 2020. Towards routine mapping of shallow bathymetry in environments with variable turbidity: Contribution of Sentinel-2A/B satellites mission. Remote Sensing 12: 451.

    Article  Google Scholar 

  • Carver, R.E. 1971. Procedures in sedimentary petrology. John Wiley & Sons.

    Google Scholar 

  • Compton, S., E. Henderson, and C. Pride. 2007. Sediment properties of water column profiles of the Wilmington River estuary (Savannah, GA). Abstracts with Programs-Geological Society of America 39 (2): 83.

    Google Scholar 

  • Cochrane, G.R., and K.D. Lafferty. 2002. Use of acoustic classification of sidescan sonar data for mapping benthic habitat in the Northern Channel Islands California. Continental Shelf Research 22: 683–690.

    Article  Google Scholar 

  • CSA (Continental Shelf Associates). 1979. South Atlantic hard bottom study. Prepared for Bureau of Land Management. NTISPB-300 821.

  • Dame, R., M. Alber, D. Allen, M. Mallin, C. Montagues, A. Lewitus, A. Chalmers, R. Gradenr, C. Gilman, B. Kjerve, J. Pinckney, and N. Smith. 2000. Estuaries of the South Atlantic Coast of North America: Their geographical signatures. Estuaries 23: 793–819.

    Article  CAS  Google Scholar 

  • Diesing, M., S.L. Green, D. Stephens, R.M. Lark, H.A. Stewart, and D. Dove. 2014. Mapping seabed sediments: Comparison of manual geostatistical object-based image analysis and machine learning approaches. Continental Shelf Research 84: 107–119.

    Article  Google Scholar 

  • Fakiris, E., D. Zoura, A. Ramfos, E. Spinos, N. Georgiou, G. Ferentinos, and G. Papatheodorou. 2018. Object-based classification of sub-bottom profiling data for benthic habitat mapping. Comparison with sidescan and RoxAnn in a Greek shallow-water habitat. Estuarine Coastal and Shelf Science 208: 219–234.

    Article  Google Scholar 

  • Fakiris, E., P. Blondel, G. Papatheodorou, D. Christodoulou, X. Dimas, N. Georgiou, S. Kordella, C. Dimitriadis, Y. Rzhanov, M. Geraga, and G. Ferentinos. 2019. Multi-frequency multi-sonar mapping of shallow habitats—Efficacy and management implications in the National Marine Park of Zakynthos Greece. Remote Sensing 11 (4): 461.

    Article  Google Scholar 

  • Fonseca, L., and B. Calder. 2005. Geocoder: An efficient backscatter map constructor.

  • Fonseca, L., C. Brown, B. Calder, L. Mayer, and Y. Rzhanov. 2009. Angular range analysis of acoustic themes from Stanton Banks Ireland: A link between visual interpretation and multibeam echosounder angular signatures. Applied Acoustics 70: 1298–1304.

    Article  Google Scholar 

  • Folk, R.L. 1980. Petrology of sedimentary rocks. Austin, TX: Hemphill Publishing.

    Google Scholar 

  • Frey, R.W., and J.D. Howard. 1986. Mesotidal estuarine sequences: A perspective from the Georgia Bight. Journal of Sedimentary Petrology 56 (6): 911–924.

    Google Scholar 

  • Gao, J. 2009. Bathymetric mapping by means of remote sensing: Methods accuracy and limitations. Progress in Physical Geography 33 (1): 103–116.

    Article  Google Scholar 

  • Griffiths, J. 1967. Scientific method in analysis of sediments, 508. New York: McGraw-Hill Book Company.

    Google Scholar 

  • Griffin, M., and V. Henry. 1984. Historical changes in the mean high-water shoreline of Georgia. Bulletin 98: Georgia Geological Survey.

  • Hayes, M.O. 1994. The Georgia Bight barrier system. In Geology of Holocene Barrier Island Systems, ed. R.A. Davis. Heidelberg: Springer Berlin.

  • Hess, K., S. White, and I. Jeong. 2016. Update to the tidal data in VDatum for Eastern Florida Georgia and South Carolina. NOAA Technical Memorandum NOS CS 37.

  • Hoyt, J., and V.J. Henry. 1967. Influence of island migration on barrier-island sedimentation. Geological Society of America Bulletin 78: 77–86.

    Article  Google Scholar 

  • Huff, L., L. Fonseca, T. Hou, and R. McConnaughey. 2009. Comparison between physical sediment samples and grain-size estimates from GeoCoder. Proceedings of the International Hydrographic Conference (HYDRO). p. 459.

  • Johnson, A.S., H.O. Hillestad, S.F. Shanholtzer, and G.F. Shanholtzer. 1974. An ecological survey of the coastal region of Georgia National Park Service Scientific Monograph Series No 3. Washington, D.C.: National Park Service.

    Google Scholar 

  • Kendall, M., O. Jensen, C. Alexander, D. Field, G. McFall, R. Bohne, and M.E. Monaco. 2005. Benthic mapping using sonar video transects and an innovative approach to accuracy assessment: A characterization of bottom features in the Georgia Bight. Journal of Coastal Research 21: 1154–1165.

    Article  Google Scholar 

  • Kjerve, B., C. Shao, and F.W. Stapor. 1979. Formation of deep scour holes at the junction of tidal creeks: An hypothesis. Marine Geology 33 (1–2): M9–M14.

    Article  Google Scholar 

  • Le Pape, O., J. Delavenne, and S. Vaz. 2014. Quantitative mapping of fish habitat: A useful tool to design spatialised management measures and marine protected area with fishery objectives. Ocean and Coastal Management 87: 8–19.

    Article  Google Scholar 

  • List, J.H., B.E. Jaffe, A.H. Sallenger Jr., S.J. Williams, R.A. McBride, and S. Penland. 1994. Louisiana Barrier Island Erosion Study: Atlas of sea-floor changes from 1878 to 1989. U.S. Geological Survey Miscellaneous Investigations Series 1–2150-B.

  • Long, J.H., T.J.J. Hanebuth, C.R. Alexander, and J. Wehmiller. 2021. Depositional environments and stratigraphy of Quaternary paleochannel systems offshore of the Georgia Bight Southeastern USA. Journal of Coastal Research 37: 883–905.

    Article  Google Scholar 

  • OCM Partners. 2021. 2010 lidar DEM: Coastal Georgia from 2010–06–15 to 2010–08–15. NOAA National Centers for Environmental Information.

  • Oertel, G. 1975. Post Pleistocene island and inlet adjustment along the Georgia coast. Journal of Sedimentary Research 45 (1): 150–159.

    Google Scholar 

  • Parrish, C.E., L.A. Magruder, A.L. Neuenschwander, and N., Forfinski-Sarkoze, M. Alonzo, and M. Jasinski. 2019. Validation of the ICESat-2 ATLAS bathymetry and analysis of ATLAS’s bathymetric mapping performance. Remote Sensing 11: 1634.

    Article  Google Scholar 

  • Sallenger, A.H., V. Goldsmith, and C.H. Sutton. 1975. Bathymetric chart comparisons: A manual of methodology, error criteria, and applications Special Reports in Applied Marine Science and Ocean Engineering (SRAMSOE) No. 66. Virginia Institute of Marine Science College of William and Mary.

  • SEAMAP-SA (Southeast Area Monitoring and Assessment Program-South Atlantic). 2001. Distribution of bottom habitats on the continental shelf from North Carolina through the Florida Keys. Washington, DC: SEAMAP-SA Bottom Mapping Workgroup, Atlantic States Marine Fisheries Commission.

    Google Scholar 

  • Stumpf, R., K. Holderied, and M. Sinclair. 2003. Determination of water depth with high-resolution satellite imagery over variable bottom types. Limnology and Oceanography 48: 547–556.

  • Swail, V., B. Lee, A. Soares, D. Resio, K. Horsburgh, T. Murty, S. Dube, M. Entel, and J. Flowerdew. 2010. Storm surge. In Proceedings of OceanObs’09: Sustained ocean observations and information for society (Vol 2), eds. J. Hall, D.E. Harrison, and D. Stammer. Venice, Italy: ESA Publication WPP-306. 21–25 September 2009.

  • Syvitski, J.P.M., K.W.G. Leblanc, and K.W. Asprey. 1991. Interlaboratory instrument calibration experiment. In Principles methods and application of particle size analysis, ed. J.P.M. Syvitski, 174–193. Cambridge: Cambridge University Press.

    Chapter  Google Scholar 

  • Turck, J., and C. Alexander. 2013. Coastal landscapes and their relationship to human settlement on the Georgia Coast. In Life among the tides: Recent archaeology on the Georgia Bight, ed. V.D. Thompson, and D.H. Thomas. Anthropological Papers of the American Museum of Natural History 98: 169–190.

    Google Scholar 

  • Umbach, M.J. 1976. Hydrographic manual, 4th ed. Washington, D.C.: National Oceanic and Atmospheric Administration.

    Google Scholar 

  • Weems, R.E., and L.E. Edwards. 2001. Geology of Oligocene Miocene and younger deposits in the coastal area of Georgia. Bulletin 131: Georgia Department of Natural Resources, Environmental Protection Division, Georgia Geologic Survey.

  • Wölfl, A.-C., H. Snaith, S. Amirebrahimi, C.W. Devey, B. Dorschel, V. Ferrini, V.A.I. Huvenne, M. Jakobsson, J. Jencks, G. Johnston, G. Lamarche, L. Mayer, D. Millar, T.H. Pedersen, K. Picard, A. Reitz, T. Schmitt, M. Visbeck, P. Weatherall, and R. Wigley. 2019. Seafloor mapping – The challenge of a truly global ocean bathymetry. Frontiers in Marine Science 6: 283.

    Article  Google Scholar 

  • Yang, Z., E. Myers, I. Jeong, and S. White. 2012. VDatum for coastal waters from the Florida shelf to the South Atlantic Bight: Tidal datums marine grids and sea surface topography. NOAA Technical Memorandum NOS CS 27.

Download references


We thank the Skidaway Institute of Oceanography shop staff and marine operations group for their engineering and field support in collecting these data.


Funding for these surveys was provided under grant awards NA13NOS4190114 and NA17NOS4190164 to the Georgia Department of Natural Resources Coastal Management Program from the Office of Ocean and Coastal Resource Management, National Oceanic and Atmospheric Administration.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Clark Alexander.

Additional information

Communicated by Brian B. Barnes

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Robinson, M., Alexander, C. & Venherm, C. Shallow Water Estuarine Mapping in High-Tide-Range Environments: a Case Study from Georgia, USA. Estuaries and Coasts 45, 980–999 (2022).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: