16S rDNA amplicon sequencing of the oral cavity microbiome of the common dolphin, harbour porpoise and stripped dolphin

The integrity and ecological sustainability of marine ecosystems are under increasing threats mainly due to long-term consequences of climate change, habitat degradation and human impact. Marine mammal species are top predators and have long life spans. Often, they need to cope with exposure to a variable combination of environmental stressors (e.g. xenobiotic pollutants) and pathogens. Therefore, marine mammals can be considered prime sentinel species of aquatic ecosystem health.The microbiota composition of each animal species is shaped by the interactions with the immune system, according to the animal physiology, diet and social habits, environmental context, among others, and has been related with either health or disease statuses of the host. Understanding host-microbe interactions in cetaceans may contribute to the identification of compromised populations, microbial markers of disease and ultimately to scientifically based population management decisions.In the present study, the oral microbiome of the 3 small cetacean species most commonly found stranded (D. delphis, S. coeruleoalba and P. phocoena) in the Iberian Atlantic coast was sequenced in order to identify discriminatory microbial fingerprints according to the animal species, age class, ecology of the animal, or cause of death. Systematic studies on marine mammal health and disease are crucial to support conservation and management actions, particularly when considering that some species of cetaceans are severely declining in Iberian Atlantic waters.