Identification of lake trout Salvelinus namaycush spawning habitat in northern Lake Huron using high-resolution satellite imagery

Abstract

The availability and quality of spawning habitat may limit lake trout recovery in the Great Lakes, but comprehensive maps of current spawning habitats are unavailable at the basin scale. Current methods used to identify lake trout spawning locations are time- and labor-intensive and spatially limited. Due to the observation that some lake trout spawning sites are relatively clean of overlaying algae compared to adjacent areas not used for spawning, we hypothesized that spawning sites could be identified using satellite imagery. Satellite imagery collected just before and after the spawning season in 2013 was used to assess whether lake trout spawning habitat could be identified based on its spectral characteristics. Results indicated that Pléiades high-resolution multispectral satellite imagery can be successfully used to estimate the vegetative cover of substrates and temporal changes in vegetative coverage, and that models developed from processed imagery can be used to identify potential shallow water lake trout spawning sites based on comparison of sites where lake trout eggs were and were not observed after spawning. Satellite imagery is a new potential tool for identifying nearshore lake trout spawning habitat across broad areas of the Great Lakes.