Geomorphic and Ecological Effects of Hurricanes Katrina and Rita on Coastal Louisiana Marsh Communities
Total Page:16
File Type:pdf, Size:1020Kb
Prepared in cooperation with Louisiana Coastal Areas Science and Technology Program and in collaboration with Louisiana State University, the Louisiana Governor’s Office of Coastal Protection and Restoration, and the University of Louisiana at Lafayette Geomorphic and Ecological Effects of Hurricanes Katrina and Rita on Coastal Louisiana Marsh Communities Open-File Report 2011–1094 U.S. Department of the Interior U.S. Geological Survey Geomorphic and Ecological Effects of Hurricanes Katrina and Rita on Coastal Louisiana Marsh Communities By Sarai C. Piazza, Gregory D. Steyer, Kari F. Cretini, Charles E. Sasser, Jenneke M. Visser, Guerry O. Holm, Jr., Leigh Anne Sharp, D. Elaine Evers, and John R. Meriwether Prepared in cooperation with Louisiana Coastal Areas Science and Technology Program and in collaboration with Louisiana State University, the Louisiana Governor’s Office of Coastal Protection and Restoration, and the University of Louisiana at Lafayette Open-File Report 2011–1094 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2011 This and other USGS information products are available at http://store.usgs.gov/ U.S. Geological Survey Box 25286, Denver Federal Center Denver, CO 80225 To learn about the USGS and its information products visit http://www.usgs.gov/ 1-888-ASK-USGS Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: Piazza, S.C., Steyer, G.D., Cretini, K.F., Sasser, C.E., Visser, J.M., Holm, G.O., Jr., Sharp, L.A., Evers, D.E., and Meriwether, J.R., 2011, Geomorphic and ecological effects of Hurricanes Katrina and Rita on coastal Louisiana marsh communities: U. S. Geological Survey Open-File Report 2011-1094, 126 p. iii Acknowledgments We wish to recognize the financial support of the Louisiana Coastal Area Science & Technology Program in accomplishing this research. We would like to thank all of the landowners who provided permission to access their properties to conduct this assessment, especially the Louisiana Department of Wildlife and Fisheries, Apache Corporation, Delacroix Corporation, Jeanerette Lumber, Louisiana Land and Exploration Company, and Miami Corporation. A tremendous amount of field, laboratory, and analytical assistance was provided by personnel from many agencies and affiliations. Five Rivers Services, LLC, staff includes Jason Byrd and Brad Griffin, and U.S. Army Engineer Research and Development Center staff includes Glen Suir. Louisiana State University personnel includes Azure Bevington, Thomas Blanchard, Dan Bond, Edward Castaneda-Moya, Jay Gore, Manoch Kongchum, Brian Milan, Alaina Owens, Eric Peterson, and Daniel Sasser. Louisiana Governor’s Office of Coastal Protection and Restoration (OCPR) personnel includes Brady Carter, Mike Miller, Tommy McGinnis, Mark Mouledous, John Troutman, and Dona Weifenbach. University of Louisiana at Lafayette personnel includes Katherine Zaunbrecher and Matt Williams. We would also like to thank Brian Perez of CH2M Hill. Evamaria Koch (University of Maryland Center for Marine Science) and Michael Beck (OCPR) reviewed the document and provided useful comments. This project could not have been completed without the field efforts, sample processing, data entry, and input of U.S. Geological Survey personnel including Gregg Snedden, Jeff Broussard, Brady Couvillion, Ada Diz, Jessica Goodwin, Arianne Logwood, Alison Martin, and Elin Sandy. iv Contents Acknowledgments ........................................................................................................................................iii Abstract ...........................................................................................................................................................1 Introduction ....................................................................................................................................................2 Materials and Methods.................................................................................................................................4 Study Area..............................................................................................................................................4 Methods..................................................................................................................................................8 Vegetation .....................................................................................................................................8 Hydrology ......................................................................................................................................8 Porewater in Soil ........................................................................................................................9 Sediment Deposition and Condition .........................................................................................9 Bulk Density and Organic Matter ..............................................................................................9 Sediment Elevation, Accretion, and Shallow Subsidence ....................................................................................................10 Statistical Analyses ............................................................................................................................10 Vegetation and Porewater Salinity .........................................................................................10 Soils .........................................................................................................................................10 Results and Discussion ...............................................................................................................................10 Recovery After Hurricanes Katrina and Rita ..................................................................................10 Summary of All Vegetation Types ...........................................................................................10 Fresh Marsh Sites ......................................................................................................................14 Brackish/Intermediate Marsh Sites .......................................................................................35 Saline Marsh Sites ....................................................................................................................39 Case Studies ........................................................................................................................................44 Case Study 1: CRMS0605-H and CRMS1277-H .....................................................................44 Overall Site Description ...................................................................................................44 Salinity Before and After the Storms .............................................................................44 Plant Biomass Before and After the Storms ................................................................44 Plant Community Change After the Storms ..................................................................49 Discussion ..........................................................................................................................56 Case Study 2: CRMS0135 ..........................................................................................................58 Overall Site Description ...................................................................................................58 Surface-Water and Porewater Salinities .....................................................................61 Vegetation Cover ...............................................................................................................61 Aboveground and Belowground Biomass ....................................................................64 Sediment Characterization, Accretion, and Elevation ................................................67 Summary of the Classification of Impacts ....................................................................67 Case Study 3: CRMS0672-H ......................................................................................................67 Overall Site Description ...................................................................................................67 Surface-Water and Porewater Salinity .........................................................................72 Vegetation Cover ...............................................................................................................72 Aboveground and Belowground Biomass ....................................................................75 Sediment Characterization, Accretion, and Elevation ................................................77 Summary of the Classification of Impacts ....................................................................80 v Case Study 4: CRMS0326-H ......................................................................................................80 Overall Site Description ...................................................................................................80 Surface-Water