Spatial Patterns and Environmental Factors Related to Arsenic Bioaccumulation in Boreal Freshwater Fish

To better understand the spatial patterns in arsenic bioaccumulation in freshwater systems, we investigated ecological, physical and chemical factors associated with total arsenic concentrations ([As]) in lacustrine and riverine fish across Ontario, Canada using a dataset of 3200 fish across 152 waterbodies. Assembled data of water chemistry, landscape characteristics, and stable carbon and nitrogen isotope ratios in muscle tissue were then used to assess factors related to As bioaccumulation. Results show [As] were generally low across most species and waterbodies (i.e., <1 µg/g wet in many inland fish). However, fish from northern coastal rivers had up to 23-fold higher [As] when compared to fish from landlocked sites. [As] increased slightly with the proportion of pelagic carbon in a fish’s diet, although relationships varied among species and sites. Furthermore, principal component scores, representing landscape and water chemistry variables, were related to [As] in fish, but these relationships varied among species. These results will help improve the efficacy of fish contaminant monitoring by further identifying key physical and ecological variables related to higher [As] in fish.