Microbial biodiversity of agricultural surface waters in Ontario, Canada

Understanding the microbial diversity is the first step to monitor the microbial quality of agricultural surface waters. Here we report a study comparing the microbial composition and diversities in agricultural surface waters in Ontario, Canada, including the streams adjacent to dairy cattle production in eastern Ontario and the field runoffs from the manure-impacted experimental farm of south-western Ontario. We also studied the quality of the surface water in the western basin of Lake Erie during a harmful algal bloom (cHAB). In eastern Ontario, we found significantly lower (<i>P</i> < 0.01) abundance of Proteobacteria and Burkholderiales in the streams adjacent to dairy production than the non-agriculture site. Bacteroidetes was more abundant (<i>P</i> < 0.0001) in medium/high order streams and agriculture/urban mixed site. Seasonal peaks of <i>Flavobacterium</i> were observed in low order streams but the trend was not in medium/high order streams. In south-western Ontario, the dominant bacterial taxa in field runoffs was <i>Pseudomonas</i>, regardless of manure types. We also discovered that the elevated total dissolved nitrogen, total dissolved phosphorus and chlorophyll a associated with the cHAB zone in Lake Erie was further away rather from the agricultural sites. In conclusion, our studies identified unique microbiome patterns associated with agricultural surface waters in Ontario.