Microbial metagenomes associated with corals living inside volcanic CO2 seeps in Papua New Guinea. PNG Coral Microbiomes

Natural volcanic seeps located in the D’Entrecastraux Islands, Milne Bay Province, Papua New Guinea expel ~99% pure CO2 gas and provide a unique opportunity to examine the effects of predicted future pCO2 conditions (pH 7.7-8.0), on tropical coral reef communities in situ. Corals rely on intimate and dynamic associations with diverse microorganisms for their health and physiology, yet little is known about how these microbial assemblages respond to changing environmental conditions. Topographic heterogeneity has shifted within the seeps, and reefs once composed of branching and plating corals are now dominated by massive boulder corals. Previous 16S rRNA gene targeted amplicon studies comparing corals living within the seep environment with adjacent control sites have shown that high pCO2/low pH “sensitive” corals (e.g. Acropora millepora, Porites cylindrica) demonstrate a significant shift in their microbial assemblages while high pCO2/low pH “tolerant” corals do not (e.g. Porites lutea, Isopora palifera). The present study aims to examine the microbial metagenomes associated with Porites lutea boulder corals that appear to be thriving inside and outside of the CO2 seeps. A set of P. lutea samples were collected from two seep sites and two control sites in April 2014 (n = 3) and sequenced on the Illumina TruSeq platform at the Ramaciotti Centre (Sydney, NSW). Examining the functional potential of this coral may provide insight into what drives a resilient microbiome in the face of a changing climate. The ability of microbes to rapidly evolve means they can shift their community dynamics, host range, metabolic capabilities and other essential functions in response to environmental changes faster than long-lived organisms.