Shark Bay is considered as a unique assembly of environments and biota, and has been classified as a World Heritage site, thus granting its international protection. However, this does not exempt it from being subjected not only to a likely major petroleum spill from the exploration and production industry activities in the North of Western Australia, but also other hydrocarbon pollutants from recreational boats or commercial vessels crossing surrounding regions, i.e. Carnarvon or Exmouth. Therefore, making of Shark Bay a high-risk environmental region (AMSA, 2012).
Shallow pristine marine ecosystems in Shark Bay region have been well-studied lately (Allen, 2006; Pagès et al. 2014, 2015; Ruvindy et al. 2015; Plet et al. 2018). However, there is no information how these habitats might change to actual environmental threatens, e.g. predicted changes in seawater levels and oil spills. In order to contribute to a better understanding of their responses of such stressors, this study is focused on monitoring changes in the microbial composition of oil-polluted intertidal Microbial Mats (MM).
In our study, MM were collected from a hypersaline benthic environment, Nilemah embayment in Shark Bay, WA. These MM have been maintained in microcosms at 25°C with sterile hypersaline water, constant sterile air flux and diel regime by artificial light. The effect of oils that have been degraded to different extents has been subjected to smooth and pustular MM communities. The incubation experiments have been sampled before and after 30, 60, and 120 days of oil pollution. Samples of MM and oil traces in the water column were taken for organic geochemical analysis and, DNA and RNA were extracted in parallel for paired bacterial 16S rDNA vs.16S rRNA profiling. Therefore, it is not only expected to reveal those taxa that are present vs. metabolically active, but also identifying a range of metabolites involved in oil biodegradation (Bordenave et al., 2007; Aitken et al. 2018).