Sydney Harbour-ing unknown coral treasures

Methods

Summary

Analysis of microbial biodiversity: Both Plesiastrea Versipora and Coscinaraea McNeilli are sampled seasonally (n=5) at 3 sites within the Harbour (Middle Head and Manly) and Botany Bay (Bare Island) on SCUBA. This is done by removing small samples of host tissue using a hammer and chisel. Samples are snap frozen in liquid nitrogen and stored until processing back in the laboratory. DNA is extracted using molecular kits following well established protocols for the amplification of target genes for bacteria (16S rRNA) and Symbiodinium using next generation sequencing. 

Pre Analysis Plan

We predict that there will be seasonal variation in bacterial community composition however a baseline community will always be present. We also predict significant changes in this community with differing environmental stressors, such as the 2015/2016 El Niño thermal anomaly, however as past research shows, the baseline bacterial population will re-establish itself when conditions return to normal. Bacterial communities are thought to provide important symbiotic functions in maintaining coral health and biochemical processes, for example. http://icb.oxfordjournals.org/...

We are expecting the Symbiodinium type to remain stable over time. The selection of Symbiodinium with certain tolerances underpins the physiological plasticity that determines the tolerance of the host coral. This is potentially a mechanism used by corals to adapt to environmental change. http://onlinelibrary.wiley.com...

By extracting the DNA of replicate samples (n=5) and analysing them using next generation sequencing, we can test these hypotheses. The data produced from the bioinformatics (QIIME pipeline for bacteria and BLAST/GeoSymbio database for Symbiodinium) analysis can tell us the dominant bacterial species present for each season and we can clearly see any changes in community structure. As the microbial communities of these corals are unknown, any data will be informative!