Perfluorinated Chemicals in Meromictic Lakes on the Northern Coast of Ellesmere Island, High Arctic Canada + Online Appendix 1 (See Article Tools)
Keywords:perfluorinated chemicals, lake, transport pathways, climate change, snow, water, sediments, arctic char, zooplankton, meromictic
Perfluorinated chemicals (PFCs) have been recorded in many types of marine and freshwater ecosystems. The aim of the present study was to examine meromictic lakes and their catchments on the far northern coast of Ellesmere Island, Nunavut, Canada, and to evaluate the results in the context of climate change. Our analyses revealed the presence of several PFCs in catchment snowpack, inflowing streams, lake water, and the aquatic food web of Lake A (83˚00ʹ N, 75˚30ʹ W), showing that dispersal of these contaminants reaches the northern limit of the terrestrial High Arctic. However, the concentrations were low (total PFCs: 27 – 754 pg L-1 for water, 134 – 848 pg L-1 for melted snow, 5 – 2149 pg g-1 wet weight for fish; PFOS: 66 pg g-1 dry weight in surficial sediments) and at or below values reported to date in the literature for other remote lakes. PFHpA, PFOA, and PFNA were the main compounds detected in water and melted snow, while PFNA, PFDA, and PFUnA were the predominant compounds in the aquatic biota, indicating their bioaccumulative potential. Salinity-temperature-depth profiles suggested that most of the present contaminant load enters the lake via streams and flows directly under the lake ice to the ocean. The onset of summer open water in this perennially ice-covered lake in response to climate warming, and the increased duration of open water in recent years, have implications for the distribution, transport, and retention of PFCs in Arctic lakes.