Investigating Bacterial Community Structure over Temporal and Spatial Scales in the Northwest Atlantic Ocean

Abstract

Bacteria are important members of every marine ecosystem and the composition of their communities has implications for global biogeochemical cycling. The Northwest Atlantic Ocean is an ecologically and economically significant region that exhibits wide ranges in physiochemical parameters that vary seasonally. In this thesis the bacterial community structure of two areas within the Northwest Atlantic Ocean, the Scotian Shelf and the Bedford Basin, were analyzed using 16S rRNA gene sequencing. The Scotian Shelf was analyzed spatially over two time points. Environmental parameters of the region, seasonality, and depth were found to heavily influence community structure. In the Bedford Basin, a weekly bacterial time series was established and the first year of data from the deepest samples were analyzed. The deep basin exhibited seasonal patterns with respect to community similarity, diversity, and composition. Overall, these datasets provide novel information regarding community composition and drivers of community shifts in this region.