Using shoreline characteristics, relative exposure, depth, and freshwater inputs as surrogate measures to identify areas potentially suitable for eelgrass (Zostera marina) in Newfoundland

Seagrasses support multiple key ecosystem functions (e.g., sediment stabilization, carbon storage, nursery habitat) in nearshore environments across all three Canadian coastlines. Eelgrass (Zostera marina) is a seagrass species that has been designated as an Ecologically Significant Species (ESS) and is the most widely distributed and abundant seagrass in Canada. Given the considerable conservation and management interest in eelgrass habitats, large-scale data aggregation efforts have been initiated to generate comprehensive distribution maps of eelgrass coverage in Canadian coastal waters. However, extensive portions of the Newfoundland coastline have not yet been surveyed for the presence of eelgrass. We combine spatial data layers describing shoreline characteristics, relative exposure index (REI), depth, and freshwater inputs to delineate areas potentially suitable for eelgrass growth in Newfoundland. We determined that many nearshore environments could potentially support eelgrass habitats but confirming eelgrass presence will require further validation and ground-truthing. Incorporating distribution models that use environmental covariates to estimate probabilities of occurrence in nearshore areas could help to strengthen these predictions. Mapping eelgrass distributions provides baseline data essential to eelgrass monitoring and implementation of coastal marine conservation, informing emergency response, and is particularly important considering the consequences associated with the potential loss of ecosystem functions in the event of eelgrass decline.


King, B.G.C., Gullage, L., Butt, K., Warren, M., Allard, K., Gregory, R.S., and Byrne, M.A. 2026. Using shoreline characteristics, relative exposure, depth, and freshwater inputs as surrogate measures to identify areas potentially suitable for eelgrass (Zostera marina) in Newfoundland. Can. Tech. Rep. Fish. Aquat. Sci. 3737: vii + 22 p.
https://doi.org/10.60825/7thp-4425