Temporal and regional variability in the skin microbiome of humpback whales along the Western Antarctic Peninsula

Abstract

The skin is the first line of defense between an animal and its environment, and disruptions in skin-associated microorganisms can be linked to an animal's health and nutritional state. To better understand the skin microbiome of large whales, high-throughput sequencing of partial small subunit ribosomal RNA genes was used to study the skin-associated bacteria of 89 seemingly healthy humpback whales (Megaptera novaeangliae) sampled along the Western Antarctic Peninsula (WAP) during early (2010) and late (2013) austral summers. Six core genera of bacteria were present in 93% or more of all humpback skin samples. A shift was observed in the average relative abundance of these core genera over time, with the emergence of four additional core genera corresponding to a decrease in water temperature, possibly caused by seasonal or foraging related changes in skin biochemistry that influenced microbial growth, or other temporal-related factors. The skin microbiome differed between whales sampled at several regional locations along the WAP, suggesting that environmental factors or population may also influence the whale skin microbiome. Overall, the skin microbiome of humpback whales appears to provide insight into animal and environmental-related factors and may serve as a useful indicator for animal health or ecosystem alterations.