Development of Submerged Aquatic Vegetation Monitoring Protocols in North Carolina

DEVELOPMENT OF SUBMERGED AQUATIC VEGETATION MONITORING PROTOCOLS IN NORTH CAROLINA DEVELOPMENT OF SUBMERGED AQUATIC VEGETATION MONITORING PROTOCOLS IN NORTH CAROLINA By: W. Judson Kenworthy1,2 Christine A. Buckel2 Dean E. Carpenter3 David B. Eggleston4 Don Field2 Cecilia S. Krahforst5 Joseph J. Luczkovich6 Gayle R. Plaia4 1109 Holly Lane, Beaufort NC 2National Oceanic and Atmospheric Administration, NOS, NCCOS, Center for Coastal Fisheries and Habitat Research, Beaufort, NC 3Albemarle Pamlico National Estuary Program, Raleigh, NC 4Center for Marine Sciences and Technology, Dept. Marine, Earth & Atmospheric Sciences, North Carolina State University, Raleigh, NC 5Coastal Resources Management Doctoral Program, East Carolina University, Greenville, NC 6Department of Biology and Institute for Coastal Science and Policy, East Carolina University, Greenville, NC Original CRFL project title: Development of a Performance-Based Submerged Aquatic Vegetation Monitoring and Outreach Program for North Carolina Applicants: Dean E. Carpenter, Joseph J. Luczkovich, W. Judson Kenworthy, David B. Eggleston and Gayle R. Plaia Project Dates: May 1, 2009 to September 21, 2012 Cover photos from top left clockwise: Aerial image near the NC Pine Knoll Shores Aquarium on Bogue Banks, North Carolina, showing dense and patchy SAV areas; underwater camera on wheeled mount; GPS, date, and time stamped underwater SAV video; screen grab of SONAR data classifying SAV in NC; sample of Vallisneria americana; and center sample of Potamogeton perfoliatus. ii iii Table of Contents List of Figures ............................................................................................................................... vii List of Tables ............................................................................................................................... xiii EXECUTIVE SUMMARY ............................................................................................................ 1 INTRODUCTION AND OBJECTIVES ........................................................................................ 4 Review of SAV Monitoring Programs ....................................................................................................................... 11 Global Programs ........................................................................................................................................................... 12 Site-Specific Programs ............................................................................................................................................... 13 Objectives ............................................................................................................................................................................. 19 METHODS ................................................................................................................................... 19 Study Sites ............................................................................................................................................................................ 19 Intensive Assessment Sites ...................................................................................................................................... 20 Newport River ......................................................................................................................................................... 21 Jarrett Bay ................................................................................................................................................................. 21 Sandy Point ............................................................................................................................................................... 22 Blounts Bay .............................................................................................................................................................. 22 Rapid Assessment Sites ............................................................................................................................................. 22 Boat-Based Monitoring Techniques .......................................................................................................................... 24 Underwater Videography ......................................................................................................................................... 24 Video Classification Training ............................................................................................................................ 26 SONAR Monitoring Method ..................................................................................................................................... 28 Diver Surveys ................................................................................................................................................................ 31 Remote Sensing Monitoring Method ........................................................................................................................ 31 Sampling Design ................................................................................................................................................................ 32 Intensive Assessment Sites ...................................................................................................................................... 32 Rapid Assessment Sites ............................................................................................................................................. 34 Time and Costs Estimates of Monitoring Methods ........................................................................................ 36 Data Analysis ...................................................................................................................................................................... 36 Fraction of SAV ............................................................................................................................................................. 36 Accuracy Assessment ................................................................................................................................................. 37 Surface Interpolation Analyses .............................................................................................................................. 37 Power Analyses for Detecting Change in SAV Abundance .......................................................................... 40 Simulated Video Transects ................................................................................................................................ 40 Simulated SONAR Transects ............................................................................................................................. 43 RESULTS ..................................................................................................................................... 44 Boat-Based Monitoring Techniques .......................................................................................................................... 44 Underwater Videography ......................................................................................................................................... 44 iv Intensive Assessment Sites ................................................................................................................................ 44 Video Classification Training and Observer Calibration ....................................................................... 54 SONAR .............................................................................................................................................................................. 60 Intensive Assessment Sites ................................................................................................................................ 60 Diver Surveys ................................................................................................................................................................ 72 Rapid Assessment Sites ............................................................................................................................................. 73 Fraction of SAV ....................................................................................................................................................... 73 Accuracy Assessment ........................................................................................................................................... 74 Power Analyses for Detecting Change in SAV Abundance .......................................................................... 74 Simulated Video Transects ................................................................................................................................ 74 Simulated SONAR Transects ............................................................................................................................. 76 Remote Sensing Results ................................................................................................................................................. 78 Accuracy Assessment of Remote Sensing .......................................................................................................... 80 Time Requirements for Monitoring Techniques 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