Remote sensing and GIS analysis of seagrass meadows in North Carolina, USA

Abstract

Seagrass meadows are a valuable and vulnerable resource which supports coastal fisheries. Spatial monitoring of seagrass meadows can improve coastal management and research with baseline inventories of change in location and areal extent through time. Vertical aerial photography is an effective but expensive approach for monitoring seagrass meadows. Remote sensing with Landsat TM is less expensive but image selection is critical because environmental factors affect detection of seagrass meadows. Interpretation of photographs (March 1985 and April 1988) provides reference data for evaluation of results with three Landsat TM images of coastal North Carolina. Agreement of the Landsat classification with reference data was as high as 72.6% for a June 1992 image. Despite limited development of coastal North Carolina, seagrasses closely associated with the mainland are relatively low in abundance and are restricted to shallower water than seagrasses nearer the uninhabited barrier islands.