Ecosystems emit biogenic volatile organic compounds (BVOCs) to facilitate ecophysiological functioning, pathogen defence and stress responses, and are thus critical to ecosystem health. In addition, BVOCs influence local and global climate through reactions that produce secondary organic aerosols, in turn, impacting cloud production and properties. While the range and volume of BVOC emissions — the ‘volatilome’ — is well-established for terrestrial systems, explicit quantification for marine systems, including corals, is lacking.
Caitlin Lawson from the University of Technology Sydney and University of Newcastle, Australia, and colleagues, use samples of Acropora intermedia and Pocillopora damicornis from Heron Island in the Southern Great Barrier Reef to characterize the volatilome and determine the influence of heat stress. A. intermedia and P. damicornis holobionts are associated with 79 and 76 BVOCs, respectively, the majority of which fall into antimicrobial and climatic functional categories. Both species, for example, emit bromoform and chlorodibromomethane, known precursors for ozone depletion but previously undetected in corals. The chemical diversity and abundance of BVOCs is significantly altered by heat stress, including a 42% reduction in BVOC variety for A. intermedia (the majority with antimicrobial functionality) and 62% for P. damicornis (the majority being climatically active).
Credit: Nature Picture Library / Alamy Stock Photo
This initial estimate of the coral volatilome for two common species indicates that BVOCs likely have a strong, yet previously undetermined, role in coral physiology and functioning. However, this healthy functioning is threatened by anthropogenic warming and corresponding BVOC interactions. Further research is thus required to better quantify the coral volatilome, including for more species, so as to better determine coral resilience to future warming.
Source: Ecology - nature.com
