Status and Trends of Inland Wetland and Aquatic Habitats, Beaumont-Port Arthur Area
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STATUS AND TRENDS OF INLAND WETLAND AND AQUATIC HABITATS, BEAUMONT-PORT ARTHUR AREA by Thomas A. Tremblay and Thomas R. Calnan* *Coastal Assistance Division, Texas General Land Office Final Report prepared for the Texas General Land Office and National Oceanic and Atmospheric Administration under GLO Contract No. 08-024 A report of the Coastal Coordination Council pursuant to National Oceanic and Atmospheric Administration Award No. NA07NOS4190144 This investigation was funded by a grant from the National Oceanic and Atmospheric Administration administered by the Texas General Land Office. The views expressed herein are those of the authors and do not necessarily reflect the views of NOAA or any of its subagencies. Bureau of Economic Geology Scott W. Tinker, Director John A. and Katherine G. Jackson School of Geosciences The University of Texas at Austin University Station Box X Austin, TX 78713 March 2009 CONTENTS EXECUTIVE SUMMARY ............................................................................................... vi Introduction............................................................................................................ vi Methods................................................................................................................. vii Bay-Estuary System, Upper Texas Coast ............................................................ viii Current Status, 2004................................................................................. viii Wetland Trends and Probable Causes, 1956–2004.................................... xi INTRODUCTION ...............................................................................................................1 Study area.................................................................................................................2 METHODS ..........................................................................................................................4 Mapping and Analyzing Status and Trends.............................................................4 Wetland Classification and Definition.....................................................................4 Interpretation of Wetlands .......................................................................................5 Historical Wetland Distribution ..................................................................5 Revision of Historical Wetland Maps..........................................................6 Current Wetland Distribution (Status).........................................................6 Field Investigations......................................................................................6 Variations in Classification..........................................................................8 Map-Registration Differences......................................................................9 Methods Used to Analyze Historical Trends in Wetland Habitats............12 Possible Photointerpretation Errors ..........................................................12 Wetland Codes...........................................................................................13 CLASSIFICATION OF WETLAND AND DEEPWATER HABITATS IN THE STUDY AREA ....................................................................................................14 Estuarine System....................................................................................................16 Palustrine System...................................................................................................18 Lacustrine System..................................................................................................21 Riverine System.....................................................................................................21 FLUVIAL-DELTAIC AND BAY-ESTUARY SYSTEMS Study Area .............................................................................................................22 General Setting of Fluvial-Deltaic and Bay-Estuary Systems...............................22 Relative Sea-Level Rise.............................................................................23 Subsidence .................................................................................................25 Faulting ......................................................................................................26 Status of Wetlands and Aquatic Habitats, 2004.....................................................28 Estuarine System........................................................................................28 Marshes (Estuarine Intertidal Emergent Wetlands).......................28 Tidal Flats (Estuarine Intertidal Unconsolidated Shores)..............29 Aquatic Beds (Estuarine Subtidal Aquatic Beds) ..........................29 Open Water (Estuarine Subtidal Unconsolidated Bottom)............29 ii Palustrine System.......................................................................................35 Marshes (Palustrine Emergent Wetlands)......................................35 Forest (Palustrine Forested and Scrub-Shrub Wetlands)...............35 Open Water and Flat (Palustrine Unconsolidated Bottom and Shore).............................................................................................35 Lacustrine and Riverine Systems...............................................................35 Open Water and Flat (Lacustrine Unconsolidated Bottom and Shore) .........................................................................35 River (Riverine Tidal and Lower Perennial) .................................35 Historical Trends in Wetland and Aquatic Habitats ..............................................36 General Trends...........................................................................................36 Probable Causes of Trends.........................................................................40 Analysis of Wetland Trends by Geographic Area .................................................40 Sabine River...............................................................................................41 Neches River..............................................................................................44 Sabine Lake................................................................................................50 Taylor Bayou .............................................................................................52 Spindletop Marsh.......................................................................................56 Anahuac .....................................................................................................58 SUMMARY AND CONCLUSIONS ................................................................................60 ACKNOWLEDGMENTS .................................................................................................64 REFERENCES ..................................................................................................................65 APPENDIX. Total habitat areas for 2004, 1979/83, and 1950’s determined from GIS data sets of the study area .........................................................68 Executive Summary Figures I. Index map of study area................................................................................................. vii II. Areal extent of selected habitats in upper coast study area in 2004.............................. ix III. Areal extent of habitats in 2004................................................................................... ix IV. Distribution of selected habitats by geographic area in 2004........................................x V. Areal distribution of major habitats in the study area in 1956, 1979/83, and 2004 ...... xii VI. Fault in Neches River valley downthrown toward the oil and gas field.................... xiii VII. Faults intersecting wetlands in the lower Neches River valley................................ xiv Executive Summary Table I. Total area of major habitats in 1956, 1979/83, and 2004.............................................. xii FIGURES 1. Hurricane-Ike-flooded pond in Anahuac National Wildlife Refuge, Chambers County.1 2. Index map showing study area.........................................................................................3 3. Index map of USGS 7.5-minute quadrangles that encompass the study area .................7 4. Index map of field-survey sites along the upper coast used for ground-truthing aerial-photo delineations and recording vegetation composition and water regimes..........8 iii 5. Classification hierarchy of wetlands and deepwater habitats showing systems, subsystems, and classes .....................................................................................................10 6. Schematic diagram showing major wetland and deepwater habitat systems ................11 7. Example of symbology used to define wetland and upland habitats on NWI maps......11 8. Spartina spp. and Andropogon glomeratus (bushy bluestem).......................................17 9. Palustrine marsh along flooded sand quarry pits near Ross Ridge................................19 10. Palustrine forest on the banks of Hillebrandt Bayou ...................................................19 11. Taxodium distichum (bald cypress) .............................................................................20 12. Palustrine forest on North Taylor Bayou.....................................................................20 13. Location of Federal and State refuges,