EELGRASS BED MAPPING WITH MULTISPECTRAL UAV IMAGERY IN ATLANTIC CANADA

Abstract. Eelgrass (Zostera marina L.) is a marine angiosperm that grows throughout coastal regions in Atlantic Canada. This study aimed to assess the capability of UAV multispectral imagery to map the presence of eelgrass beds within two estuaries in Atlantic Canada (Souris River and Richibucto River). The images were mosaicked using Agisoft and calibrated in reflectance. The corrected images were classified using a non-parametric supervised classifier (Random Forests). The input features of the classification were the UAV band reflectance and associated bathymetric ratios and vegetation indices. The resulting maps were compared with sonar data. The overall validation accuracy for presence/absence was 91.30% with the Souris image and 86.92%% with the Richibucto images. The limitations of the study are also presented.