Characterization of skin- and intestine-associated microbial communities in migrating high Arctic lake whitefish and cisco. undefined

At high latitudes, lake whitefish (Coregonus clupeaformis) can be diadromous, transitioning seasonally between freshwater lakes and the Arctic Ocean, with others in the Coregonus species complex (CSC) including cisco (C. autumnalis and C. sardinella), showing similar migratory behaviour. CSC skin- and intestine-associated microbiomes were collected with the aid of Inuit fishers at fishing sites on and around King William Island, Nunavut, at the northern range limits of lake whitefish. After sequencing using 16S rRNA gene primers, microbiota grouped distinctly depending on fishing site salinity and geography. Overall, lake whitefish bacterial communities were more variable than cisco and showed higher Shannon diversity, suggesting that lake whitefish and their microbiomes could be susceptible to dysbiosis and environmental stress. Lake whitefish showed lower condition (K), in the ocean than in freshwater riverine habitats, whereas cisco condition was similar in seasonal habitats. Taken together, the impact of changing habitats on fish condition and microbial composition may inform approaches to CSC health in fisheries and aquaculture, in addition to being particularly relevant for northern Indigenous peoples with subsistence and economic interests in these resources.