Grant: Discovery Grants Program - Individual

Rationale The use of environmental DNA (eDNA), metagenomics and metatranscriptomics (meta-omics) in the last two decades has expanded our understanding of the astonishing protist and prokaryote diversity and their global ecological relevance. We aim to use meta-omics to investigate the diversity and ecological relevance of microbial organisms inhabiting marine coastal and riverine environments of New Brunswick (NB). We will investigate seasonal variations in the composition of microbial communities and their gene expression levels to identify the ecological roles played by protists and prokaryotes. Our investigation will be useful to identify microbial biotic indicators of the ecosystem's health and stability. The proposal comprises field work on traditional unceded territories of the Mi'kmaq people, but no direct involvement of their communities is anticipated. Current progress We use eDNA-based approaches to study microbial communities in different Maritime Canada (MC) environments affected by 1) sea level rising (mudflats and salt marshes in the Bay of Fundy) and by 2) the increasing presence of toxigenic cyanobacteria (NB rivers and lakes). Our ongoing research projects have identified certain protists and bacteria with predicted major ecological roles in those important MC ecosystems. We aim to continue and expand our investigations on MC microbial communities. Research plan The proposal comprises three research objectives (RO) focused on the diversity and metabolic activity of protists and prokaryotes inhabiting marine coastal (RO1) and riverine (RO2) ecosystems of NB, respectively. The first two ROs involve the use of eDNA/RNA-based methods to study the composition and gene expression levels of microbial communities in estuarine and riverine environments. The common aim or RO1-2 is the identification of the microbial groups responsible of the main ecological roles (e.g., primary production) in those environments. We also aim to identify biotic interactions (e.g., parasitism) important for the community dynamics, and corelated with the health of those ecosystems. The RO3 will investigate taxa of interest (RO1-2 outcomes) at deep genomic level, aiming to better understand the basic biology of ecologically relevant taxa in each environment of interest. Our studies will allow to infer the ecological roles played by microbial groups that have been marginally investigated (protists) to date, and to better understand their interactions with the deeply studied "macro" biological components (human activities, wildlife) in those important NB ecosystems. Ultimately, our planned comparative studies will identify microbial indicators of ecosystem health and perturbation (e.g., absence/presence and abundance of key microbial taxa), which will be an important, and currently lacking, source of information for the establishment of more integral ecosystem monitoring, conservation, and restoration strategies in MC coastal and riverine environments.