Methane (CH4), a potent greenhouse gas, is produced in the sediment and water column of aquatic ecosystems. The release of CH4 to the atmosphere is partially mitigated by CH4 oxidizing microorganisms (Ferry & Lessner, 2008; Kiene, 1991; Koo & Rosenzweig, 2021). This work focused on Placentia Bay, the largest bay on the southern coast of the Island of Newfoundland. Placentia Bay is influenced by several marine sources which could introduce CH4 to coastal Newfoundland. Furthermore, 18% of the landmass of Newfoundland is peatland bogs, which are hotbeds of CH4 production (Mahdianpari et al., 2020; Pelletier et al., 2007; Rydin & Jeglum, 2010; Wang et al., 2019) . Here, I present dissolved CH4 concentrations from one peatland and two catchment rivers that flow into the bay, as well as CH4 concentrations and oxidation rates in the bay. Additionally, nutrient and dissolved organic carbon data provide evidence of the microbial dynamics that may influence CH4 concentrations. This study provides an initial assessment of CH4 dynamics within Placentia Bay and its tributaries.