Spatial patterns of microbial communities across surface waters of the Great Barrier Reef

• Published in: Communications biology 2020-08, Vol.3 (1), p.442, Article 442
• Main Authors: Frade, Pedro R., Glasl, Bettina, Matthews, Samuel A., Mellin, Camille, Serrão, Ester A., Wolfe, Kennedy, Mumby, Peter J., Webster, Nicole S., Bourne, David G.
• Format: Article
• Language: English
• Subjects: 45/77; 631/158/2446/2447; 631/158/2446/837; 631/158/2452; 631/158/855; Bacteria; Bacterioplankton; Biodegradation; Biogeochemistry; Biology; Biomedical and Life Sciences; Coral reefs; Ecosystems; Flavobacteriaceae; Life Sciences; Niches; Nutrient dynamics; Nutrient loading; Nutrients
• ISSN: 2399-3642; 2399-3642
• DOI: 10.1038/s42003-020-01166-y

Microorganisms are fundamental drivers of biogeochemical cycling, though their contribution to coral reef ecosystem functioning is poorly understood. Here, we infer predictors of bacterioplankton community dynamics across surface-waters of the Great Barrier Reef (GBR) through a meta-analysis, combining microbial with environmental data from the eReefs platform. Nutrient dynamics and temperature explained 41.4% of inter-seasonal and cross-shelf variation in bacterial assemblages. Bacterial families OCS155, Cryomorphaceae, Flavobacteriaceae, Synechococcaceae and Rhodobacteraceae dominated inshore reefs and their relative abundances positively correlated with nutrient loads. In contrast, Prochlorococcaceae negatively correlated with nutrients and became increasingly dominant towards outershelf reefs. Cyanobacteria in Prochlorococcaceae and Synechococcaceae families occupy complementary cross-shelf biogeochemical niches; their abundance ratios representing a potential indicator of GBR nutrient levels. One Flavobacteriaceae-affiliated taxa was putatively identified as diagnostic for ecosystem degradation. Establishing microbial observatories along GBR environmental gradients will facilitate robust assessments of microbial contributions to reef health and inform tipping-points in reef condition. Pedro R. Frade et al. analyze published bacterial data and environmental data from the eReefs platform to study bacterioplankton community dynamics across the Great Barrier Reef. They identify communities within inshore and outershelf reefs that are susceptible to nutrient and temperature changes, highlighting the importance of understanding microbial ecosystems dynamics informing reef health.