Mark R. Byrnes, Ph.D.

Education                                                                                                      

1988    Ph.D., Oceanography, Old Dominion University
1978    B.A., Earth Science, Millersville University

Project Experience

Dr. Byrnes has conducted and managed projects focused on coastal sedimentation processes and regional response of beaches, inlets, and marshes to surface water hydrologic processes. Example projects include Operational Sediment Budget for the Outer Coast of Louisiana: Raccoon Point to Sandy Point; Determining Recent Subsidence Rates in Coastal Louisiana: Implications for Engineering and Design of Coastal Restoration Project; Potential Physical Environmental Impact of Oil and Gas Operations on Wetland Habitat in Coastal Louisiana; Shoreline Compilation and Change Assessment for the Louisiana Barrier Island Comprehensive Monitoring Program; Sediment Transport Pathways and Budget for the Barrier Islands of South Louisiana; Sediment Budget Development and Coastal Processes Analyses Toward Implementation of the Barrier Island Restoration Program for Coastal Mississippi; Quantifying Consolidation Settlement Associated with Barrier Beach Restoration in Coastal Louisiana; Damage Assessment Associated with Oiled Wetlands in the Northern Gulf of Mexico; Sediment Budget Evaluation for Mobile Bay; Channel Dredging Impacts on Shoreline Response at and Adjacent to Main Pass, Mobile Bay Entrance, Alabama; Environmental Survey of Identified Sand Resource Sites Offshore Alabama, Central East Florida, North Carolina, New Jersey, and New York; Inlet Sediment Transport Patterns at Grays Harbor, WA and Development of an Entrance Sediment Budget; and Regional Analysis of Sediment Transport and Dredged Material Disposal Patterns, Columbia River Mouth, Washington/Oregon.

Coastal Change Assessment and Sediment Budgets

• Since 1984, Dr. Byrnes has contracted with Federal and State agencies to develop state-of-science methods for compiling and analyzing historical hydrographic and shoreline surveys for quantifying change in the coastal zone. Detailed procedures were developed for compiling historical map data, where conversion from various cartographic parameters to a common coordinate system, map projection, ellipsoid, and datum is critical for accurately assessing change and associated potential measurement uncertainties. These data represent the most basic and useful information for evaluating local and regional sediment transport dynamics and their influence on coastal evolution.  Applied Coastal personnel rely on hydrographic and shoreline surveys for basic and applied scientific research on sediment transport dynamics in the coastal zone, including developing coastal sediment budgets. Dr. Byrnes also has applied these techniques in wetland environments for evaluating causes of wetland change.

Processes Affecting Wetland Change

• Wetland loss or gain is a function of natural processes such as sediment supply, waves and currents, subsidence and other geological controls, and sea-level change, as well as human activities in the coastal zone and within watersheds impacting coastal environments. Dr. Byrnes has conducted numerous projects focused on evaluating natural processes and human activities related to changes documented via shoreline mapping using maps, aerial imagery, and Lidar. Recent projects have addressed the magnitude of consolidation settlement associated with beach restoration along the outer coast of Louisiana, as well as determining subsidence rates using high-resolution GPS measurements associated with natural consolidation of sediment in a deltaic environment. These data are critical for understanding the evolution of wetlands because subsidence represents the dominant signal associated with relative sea-level rise in south Louisiana deltaic wetlands.

Impact of Navigation Channels and Coastal Structures on Shoreline Change

• Dr. Byrnes has evaluated the impact of coastal structures on sediment transport dynamics and coastal evolution throughout the U.S. He has been principal investigator on several projects assessing the influence of navigation and shore protection structures on beach response, including an evaluation of beach change to construction of 85 segmented breakwaters offshore southwestern Louisiana and an assessment of downdrift beach evolution in response to jetty construction at St. Marys Entrance, GA/FL; Grays Harbor and Columbia River, WA; Port Canaveral and Sebastian Inlet, FL; and Mattituck and Goldsmith Inlets, Southold, NY; and the Montauk Inlet, Montauk, NY.  More recently, Dr. Byrnes has evaluated the impact of channel dredging on sand bypassing and littoral sediment transport processes for coastal Alabama and Mississippi, and for beaches on Long Island, NY. All projects relied on the application of GIS tools for accurate compilation and analysis of survey data sets.

Offshore Sand Resource Evaluations

• Dr. Byrnes has conducted offshore sand resource evaluations for determining the sedimentary characteristics of deposits and associated potential environmental issues concerning sand mining on the Continental Shelf.  The geographic extent of these studies ranges from coastal Louisiana to offshore Massachusetts. Dr. Byrnes’ primary interest is with the geological development of offshore shoals and the physical environmental effects of dredging activities in altering fluid and sediment transport patterns at potential borrow sites and along shorelines landward of resource areas.  Analyses rely on comparison of bathymetry and shoreline data sets and numerical modeling of waves and currents over variable bathymetry.  Analysis results supply information for policy decisions regarding potential dredging effects and for development of impact reports required under the National Environmental Policy Act in support of potential lease agreements.

Selected Publications

Byrnes, M.R., R.J. Hollis, S.M. Khalil, L.D. Britsch, J.L. Berlinghoff, R. Raynie, and E. Haywood, 2023. Recent subsidence trends in Terrebonne Basin, Louisiana. In: P. Wang, E. Royer, and J.D. Rosati (eds.), Coastal Sediments 2023, World Scientific, Hackensack, NJ, 1752-1765.

Byrnes, M.R., J.L. Berlinghoff, R.J. Hollis, R. Johnson, and T. Miller, 2023. Stability of Reference Monuments for Documenting Elevation Changes in Consolidating Holocene Sediment in South Louisiana Coastal Environments. Final Report prepared for Coastal Protection and Restoration Authority of Louisiana, Baton Rouge, LA, 17 p. plus Appendices.

McBride, R.A., Anderson, J.B., Buynevich, I.V., Byrnes, M.R., Cleary, W., Fenster, M.S., FitzGerald, D.M., Hapke, C.J., Harris, M.S., Hein, C.J., Johnson, C.L., Klein, A.H.F., Liu, B., de Menezes, J.T., Mulhern, J.S., Oliver, T.S.N., Pejrup, M., Riggs, S.R., Roberts, H.H., Rodriguez, A.B., Seminack, C.T., Short, A.D., Stone, G.W., Tamura, T., Wallace, D.J., Wang, P., 2022. Morphodynamics of Modern and Ancient Barrier Systems: An Updated and Expanded Synthesis. In: Shroder, J.J.F. (Ed.), Treatise on Geomorphology, vol. 8. Elsevier, Academic Press, pp. 289–417. https://doi.org/10.1016/B978-0-12-818234-5.00153-X

Byrnes, M.R., R.J. Hollis, L.D. Britsch, J.L. Berlinghoff, and R. Johnson, 2022. Recent Subsidence Trends for Coastal Louisiana: Phase 4 – Southwestern Louisiana Chenier Plain, Teche/Vermilion Basin, Atchafalaya Basin, Western Pontchartrain Basin, and the Mississippi River Delta Basin. Final Report prepared for Louisiana Coastal Protection and Restoration Authority, Baton Rouge, LA, 80 p. plus appendices.

Byrnes, M.R. and R.J. Hollis, 2020. Consolidation Settlement Associated with Beach Restoration Along the Caminada Headland Shoreline, LA: February 2013 to March 2020. Final Report prepared for Louisiana Coastal Protection and Restoration Authority, Baton Rouge, LA, 29 p.

Byrnes, M.R., L.D. Britsch, J.L. Berlinghoff, and R. Johnson, 2019. Recent subsidence rates for Barataria Basin, Louisiana. Geo-Marine Letters, https://doi.org/10.1007/s00367-019-00573-3.

Byrnes, M.R., J.L. Berlinghoff, and B.S. Beasley, 2019. Louisiana Operational Sediment Budget: Raccoon Point to Sandy Point, 1985-89 to 2013-16. Final Report prepared for Louisiana Coastal Protection and Restoration Authority, Baton Rouge, LA, 118 p. plus appendices.

Berlinghoff, J.L., M.R. Byrnes, and S.M. Khalil, 2019. Barrier island system deterioration in south Louisiana: Geomorphic change and implications for restoration. In: P. Wang, J.D. Rosati, and M. Vallee (eds.), Coastal Sediments 2019, World Scientific, Hackensack, NJ, 199-214.

Beasley, B.S., I.Y. Georgiou, M.D. Miner, and M.R. Byrnes, 2019. Coupled barrier system shoreline and shoreface dynamics, Louisiana, USA. In: P. Wang, J.D. Rosati, and M. Vallee (eds.), Coastal Sediments 2019, World Scientific, Hackensack, NJ, 173-186.

Byrnes, M.R., J.L. Berlinghoff, S.F. Griffee, A.R. Fallon, and D.M. Lee, 2018. Louisiana Barrier Island Comprehensive Monitoring Program (BICM): Phase 2 – Updated Shoreline Compilation and Change Assessment, 1880s to 2015. Prepared for Louisiana Coastal Protection and Restoration Authority (CPRA) by Applied Coastal Research and Engineering, Baton Rouge, LA and Mashpee, MA, in cooperation with CDM Smith, Baton Rouge, LA, 46 p. plus appendices.

Mendelssohn, I.A., M.R. Byrnes, R.T. Kneib, and B.A. Vittor, 2017. Chapter 6, Coastal Habitats of the Gulf of Mexico. In: C.F. Ward (ed), Habitats and Biota of the Gulf of Mexico: Before the Deepwater Horizon Oil Spill, Volume 1, Springer Open, New York, NY, 359-640.

Byrnes, M.R., J.D. Rosati, S.F. Griffee, and J.L. Berlinghoff, 2013. Historical sediment transport pathways and quantities for determining an operational sediment budget: Mississippi Sound barrier islands. In: Brock, J.C., Barras, J.A., and Williams, S.J. (eds.), Understanding and Predicting Change in the Coastal Ecosystem of the Northern Gulf of Mexico, Journal of Coastal Research, Special Issue, No. 63, pp. 166-183.

Byrnes, M.R. and J.L. Berlinghoff, 2012. Gulf Regional Sediment Management Master Plan: Case study compilation. In: S.M. Khalil, L.E. Parson, and J.P. Waters (eds.), Technical Framework for the Gulf Regional Sediment Management Plan (GRSMMP), Journal of Coastal Research, Special Issue 60, pp. 72-124.