Effects of thermal stress on amount, composition, and antibacterial properties of coral mucus

• Published in: PeerJ (San Francisco, CA) Vol. 7; p. e6849
• Main Authors: Wright, Rachel M, Strader, Marie E, Genuise, Heather M, Matz, Mikhail
• Format: Journal Article
• Language: English
• Published: United States PeerJ. Ltd 29.04.2019; PeerJ, Inc; PeerJ Inc
• Subjects: Acropora cervicornis; Algae; Antibacterial activity; Antibacterial agents; Carbon; Climate change; Climate Change Biology; Coral bleaching; Coral reef; Coral reef ecosystems; Coral reefs; Corals; Ecology; Ecosystem assessment; Ecosystem biology; Ecosystems; Experiments; Heat; Marine Biology; Marine ecology; Marine ecosystems; Metabolism; Molecular Biology; Mortality; Mucus; Photosynthesis; Protection and preservation; Reefs; Shipping industry; Symbionts; Symbiosis; Florida Keys; United States > US; Climate change; Coral reef; Coral bleaching; Mucus; Acropora cervicornis
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.6849

The surface mucus layer of reef-building corals supports feeding, sediment clearing, and protection from pathogenic invaders. As much as half of the fixed carbon supplied by the corals' photosynthetic symbionts is incorporated into expelled mucus. It is therefore reasonable to expect that coral bleaching (disruption of the coral-algal symbiosis) would affect mucus production. Since coral mucus serves as an important nutrient source for the entire reef community, this could have substantial ecosystem-wide consequences. In this study, we examined the effects of heat stress-induced coral bleaching on the composition and antibacterial properties of coral mucus. In a controlled laboratory thermal challenge, stressed corals produced mucus with higher protein (  = 2.1,  < 0.001) and lipid content (  = 15.7,  = 0.02) and increased antibacterial activity (likelihood ratio = 100,  < 0.001) relative to clonal controls. These results are likely explained by the expelled symbionts in the mucus of bleached individuals. Our study suggests that coral bleaching could immediately impact the nutrient flux in the coral reef ecosystem via its effect on coral mucus.