Date of Award


Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Biological Sciences (MS)

Administrative Home Department

Department of Biological Sciences

Advisor 1

Stephen Techtmann

Committee Member 1

Gordon Paterson

Committee Member 2

Rupali Datta

Committee Member 3

Amy Marcarelli


With increased demand for oil, there is an increased risk for oil spills in many environments. A number of pipelines transport oil near or across freshwater systems including the Great Lakes. Microbes are capable of breaking down oil and have thus been proposed as tools for oil spill response through bioremediation. There is a need to understand the microbial response to diverse oil types in freshwater environments due to the lack of research into this topic. This study’s main objectives are to understand how the freshwater microbial communities respond to oil, and how the bacterial communities may respond to different oil types. The bacterial community response to oil was examined at seven different geographical locations in the Great Lakes. Additionally, the microbial community response to two very different oil types. A heavy oil, Cold Lake Diluted Bitumen (DilBit), and a light oil (Bakken) were examined. Our results demonstrated a distinct community composition at different sites throughout the Great Lakes. Furthermore, there was a distinct response to oil depending on the location. Additionally, our results showed a distinct community response to the two oil types tested Bakken and DilBit crudes. The primary organisms that responded to oil in our microcosms in the Great Lakes were bacteria from the families; Sphingomonadaceae, Rhodocyclaceae, Burkholderiales, and Comamonadacea. Our results also indicated that the extent of response to oil varied greatly between offshore, the Straits, and inland systems. These findings suggest that in the case of an oil spill in the Great Lakes, the location of the spill and type of oil should be taken into account in planning bioremediation efforts. Our results demonstrate that in most locations in the Great Lakes, a common group of bacteria can be expected to respond to the oil exposure indicating the potential for oil biodegradation throughout the Great Lakes.