The goals of this project are to develop a long-term record of seagrass bed extent, focusing primarily on the historical changes that have occurred to the deep-edge, and tie this in with historical changes in water-quality. The data gathered from this internship project will be used to calibrate a model of light attenuation for seagrass habitat requirements. This model is being developed as a tool to assist managers with monitoring water-quality to protect seagrasses, a critical estuarine habitat in North Carolina.

ArcMap was used to create maps that show how Chlorophyll a, TSS, and CDOM affect water quality. Pathfinder Office was used to locate the deep-edge sites, and to put the site locations into ArcMap. Each map showed how one component’s value affected water quality for one day. These raster layers were then combined using the spatial analyst extention in ArcMap to form a raster layer that gave important information on how predefined thresholds were being exceeded. The thresholds are the highest values of CDOM, TSS, and Chlorophyll that can be present and still allow enough sunlight to get to the seagrass. Areas where the thresholds were exceeded are unfavorable for seagrass growth.

Future developments for this model aim to include remote-sensing information in near-real time to enable timely and appropriate management actions to be made.