The marine mammal microbiome: current knowledge and future directions

Marine mammals are globally significant because of their
sensitivity to environmental change and threatened status,
often serving as ‘ecosystem sentinels’1. Disease is a major
cause of marine mammal population decline and the role of
the microbiome in disease has generated considerable
interest. Recent research in humans has greatly enhanced
our understanding of how the host-associated microbial
community, the microbiome, affects host health. In this
review, we provide an overview of the extent of the marine
mammal microbiome with a focus on whole community
characterisation using genomic methods. This research
highlights the overlap in microbial communities between
geographically distinct species and populations of marine
mammals, suggesting tight links between marine mammals
and their microbial symbionts over millions of years of
evolution. An understanding of these links in both healthy
and compromised hosts is essential to identifying at-risk
populations and making ecologically appropriate management
decisions. We advocate further development of
innovative sampling and analytic techniques that advance
the field of microbial ecology of marine mammals.