To characterize and compare the gut microbiome of grey seals (Halichoerus grypus) by amplify 16S rDNA sequencing of rectal faecal samples from different age groups of grey seals resident in different environments on the Isle of May, Scotland.

ABSTRACT:Grey seals can act as a sentinel species reflecting the condition of the environment they inhabit. Rectal swab samples were collected from live grey seal pups and yearlings from the Isle of May, Scotland. Previous research identified strains of pathogenic Campylobacter and Salmonella in these faecal samples, originating from both human and agricultural hosts (Bailey et al., 2014, 2016). To gain further understanding of the environmental status of their habitat, the microbiota of both the pups and the yearling grey seals was examined.DNA was extracted from rectal swabs (n=32) using an optimised procedure, and the 16S rDNA sequenced to identify the microbiome of each individual. Differences in the microbiome profile between seal pups from different geographical locations/habitats on the same island and seals at two different ages (pups and yearlings), were compared.There were significant differences in microflora composition between yearlings and pups, as well as more subtle differences when comparing pups from the different environments in which they were born. This preliminary study therefore suggests that seal microbiomes are sensitive to environmental/habitat change as well as age dependent.