Differential presence of anthropogenic compounds dissolved in the marine waters of Puget Sound, WA and Barkley Sound, BC

► Anthropogenic vanillin is the most abundant cooking spice found in Puget Sound. ► Puget Sound has a significant anthropogenic source for salicylic acid. ► Amounts of anthropogenic compounds are greater in Puget Sound than Barkley Sound. ► Some compounds investigated have both a natural and anthropogenic source. ► Abundances for certain compounds in Puget Sound suggest overlapping sources. Organic compounds were evaluated in March 2010 at 22 stations in Barkley Sound, Vancouver Island Canada and at 66 locations in Puget Sound. Of 37 compounds, 15 were xenobiotics, 8 were determined to have an anthropogenic imprint over natural sources, and 13 were presumed to be of natural or mixed origin. The three most frequently detected compounds were salicyclic acid, vanillin and thymol. The three most abundant compounds were diethylhexyl phthalate (DEHP), ethyl vanillin and benzaldehyde (∼600ngL−1 on average). Concentrations of xenobiotics were 10–100 times higher in Puget Sound relative to Barkley Sound. Three compound couplets are used to illustrate the influence of human activity on marine waters; vanillin and ethyl vanillin, salicylic acid and acetylsalicylic acid, and cinnamaldehyde and cinnamic acid. Ratios indicate that anthropogenic activities are the predominant source of these chemicals in Puget Sound.