Characterization of Microbial Communities of the Utikuma Region Study Area (Alberta, Canada)

Abstract

Understanding the drivers of bacterial communities and the dynamics of boreal ecosystems is critical for safeguarding water quality and ecosystem resilience in the face of environmental change. This study investigates the interplay between cyanobacterial dynamics and ecohydrologic factors in the Utikuma Region Study Area (URSA) of northern Alberta. Cyanobacteria play a pivotal role in oxygenic photosynthesis and nutrient cycling, yet their unchecked proliferation can lead to harmful algal blooms with significant ecological and economic consequences. Field sampling was conducted in 34 URSA ponds using a two-phase filtration process designed to capture both larger microbial and picocyanobacterial cells. DNA was extracted and analyzed through 16S rRNA gene sequencing, with taxonomic assignments derived from the curated CyanoSeq 1.3 database and complementary methods. Advanced bioinformatics pipelines provided high-resolution community profiling, while statistical analyses—including redundancy analysis and PERMANOVA—linked microbial diversity patterns to water chemistry parameters (e.g., pH, nutrients, trace metals) and ecohydrologic variables such as hydrologic relief areas, hydrologic units, and wildfire disturbances. Key findings indicate that environmental factors explain up to 23.9% of the variance in microbial composition based on clr-transformed RDA. Notably, landscape-scale drivers and wildfire history significantly influenced community structure, with their interactions accounting for up to 30.1% of the variance (PERMANOVA). Dominant phyla observed included Pseudomonadota, Bacteroidota, Actinomycetota, Cyanobacteriota, and Verrucomicrobiota, while analysis of 165 cyanobacterial Amplicon Sequence Variants highlighted taxa such as Prochlorococcaceae and Aphanizomenonaceae. These results, while based on a specific sampling period, provide valuable foundational insights into the relationships between ecohydrologic drivers and microbial community structure for a region previously uncharacterized in this regard. This work sets the stage for further research to refine taxonomic methods and inform targeted water quality management strategies in boreal ecosystems.