Legare, B. and Mace, C., 2017. Mapping and classifying Eastern Oyster (Crassostrea virginica) habitat in Copano Bay, Texas, by coupling acoustic technologies.
The Texas coast is characterized by an extensive array of shallow turbid embayments containing expansive oyster habitats and is home to a large Eastern Oyster (Crassostrea virginica) fishery. Mapping habitats in shallow (1–10 m), turbid environments is challenging, since direct visual access to the habitats limited. To quantify the extent of habitats, the integration of remote sensing and GIS technologies is used. The Texas Parks and Wildlife Department coupled two acoustic technologies (sidescan sonar and echosounder) to map habitats within Copano Bay, a 181-km2 shallow water embayment along the mid-Texas coast. Data were collected during 17 days from September 2013 to February 2014 and resulted in 159 km2 of sidescan imagery and 375 km of single beam echosounder data. Individual echosounder transmissions were segmented and processed in ArcGIS 10.1 using the “Unsupervised Classification” tool. Using the classified echosounder data to identify objects located within the sidescan imagery allows for interpolation of habitat using the National Oceanic and Atmospheric Administration's Habitat Digitizer ArcGIS Extension. A total of 25.9 km2 of oyster habitat, 11.6 km2 of shell, 26.4 km2 of sand, and 95.1 km2 of mud were digitized. The resulting habitat map had an overall accuracy of 86% from ground truthing accuracy assessments. This article provides methods for combining sidescan and echosounder acoustic technologies to accurately map habitats in shallow Texas estuaries.
