Submerged Aquatic Vegetation Habitat Product Development: On-Screen Digitizing and Spatial Analysis of Core Sound Chelsea Vick, Patrina Bly, Michael Jefferson Mentors: Elizabeth Brinker & Dr. Benjamin Branch Undergraduate Research Experience GIS Team 2009-2010 Elizabeth City State University, 1704 Weeksville Road, Elizabeth City, North Carolina 27909

ABSTRACTA hydrophytes of high relevance, submerged aquatic vegetation (SAV) is of great importance to estuarine environments. SAV helps improve water quality, provides food and shelter for waterfowl, fish, and shellfish, as well as protects shorelines from erosion. In coastal bays most SAV was eliminated by disease in the 1930’s. In the late 1960’s and 1970’s a dramatic decline of all SAV species was correlated with increasing nutrient and sediment inputs from development of surrounding watersheds. Currently, state programs work to protect and restore existing wetlands, however, increasing development and population pressure continue to degrade and destroy both tidal and non-tidal wetlands and hinder overall development of SAV growth.

The focus of this research was to utilize spatial referencing software in the mapping of healthy submerged aquatic vegetation (SAV) habitats. In cooperation with the United States Fish and Wildlife Service (USFWS), and the National Oceanic and Atmospheric Administration (NOAA), students from Elizabeth City State University (ECSU) developed and applied Geographic Information Systems (GIS) skills to evaluate the distribution and abundance of SAV in North Carolina’s estuarine environments.

Utilizing ESRI ArcGIS, which includes ArcView, ArcCatalog and ArcToolbox, and the applications of on-screen digitizing, an assessment of vegetation cover was made through the delineation of observable SAV beds in Core Sound, North Carolina. Aerial photography of the identified coastal water bodies was taken at 12,000 feet above mean terrain (AMT) scale 1:24,000. The georeferenced aerial photographs were assessed for obscurities and the SAV beds were digitized. Through the adoption of NOAA guidelines and criteria for benthic habitat mapping using aerial photography for image acquisition and analysis, students delineated SAV beds and developed a GIS spatial database relevant to desired results. This newly created database yielded products in the form of usable shapefiles of SAV polygons, as well as attribute information with location information, area in hectares, and percent coverage of SAV.

Why is SAV Important?•Improves water quality •Provide fisheries habitat•Protects shoreline from erosion•Covers 10% of worlds coastal oceans•Bio-Indicator•SAV distribution and abundance decides TMDL•Economically important fisheries

Methodology•Core Sound, NC•ESRI ArcGIS 9.2

•Used to model the Submerged Aquatic Vegetation.•Spatial Analyst tools were used to classify the SAV density

•Aerial Photography•Digitizing Process

Study Area

ArcMap 9.2ArcMap is the main component of ESRI’s ArcGIS suite of geospatial processing programs, and it is used primarily to view, edit, create, and analyze geospatial data. It was used to do all of the digitizing of the SAV.

Aerial Photography •Cooperative SAV habitat mapping program, which consists of NOAA, USFWS, NCDENR, collected the aerial photography, following CGIA criteria (i.e. Executive Order 12906)October of 2007 Intergraph Z/I Digital Mapping Camera with a

resolution of 0.3 meters•Images were rectified (i.e. geographic location information) and mosaiced•Technical issues (Deleted to create consistency)Cloud Cover Land Null/Void .tiff

Digitizing Process1. Create New Feature2. Select the Target layer and click a line or

polygon layer3. Choose the Sketch tool4. Click the map to digitize the feature’s

vertices5. When finished right click on the map to

finish the sketch

Digitizing Process• Identified the amount of SAV

present in a polygon• Used a classical technique

developed by Paine (1981)Used by Orth et al. from the

Virginia Institute of Marine Science

NOTE: above method adopted on instance that initial “eyeballing” method yielded to conflicting variances, and lack of continuity.

% of SAV Density% of SAV Density0-10

10-4040-70

70-100

Results

This screenshot shows attribute table of the polygons 1-40. The Columns are the ID, Shapes(polygons) the given ID, and the Percent Coverage (Percent_Co). The Percent_Co was entered manually.

Analyzed and delineated multiple survey areas for Submerged Aquatic Vegetation (SAV)Density of SAVSAV trend areasUtilizing various spatial analyst toolsQuality assurance and quality control (QAQC)

ConclusionSubmerged aquatic vegetations are species of great relevance. They hold vital roles as it pertains to marine ecosystems and in the process of sustaining life. Through the development of the current GIS package visual data on a relatively large scale is available. It shows the SAV that is currently present in North Carolina Core Sound, as well as density distribution

Future Works•Completion Digitizing spatial joinstatistical analysis•SAV Distributionspecies type•GIS developmentdecadal comparison of distribution •Shareweb portaldistribute data to USFWSIGARSS 2010

Acknowledgements• Elizabeth Brinker & Dr. Benjamin Branch • NOAA and USFWS• Center of Excellence in Remote Sensing

Education and Research