Water chemistry and benthic pigments in the Lake Meretta wetlands, Resolute Bay, Nunavut

The Meretta wetlands are an extensive area of shallow lakes, ponds and streams that mostly drain into Meretta Lake, in the Resolute Bay area, on Cornwallis Island in the Canadian High Arctic. The terrain is polar desert, with extensive landform modifications due to airport and road construction activities from the 1950s onwards. At least some of the basins were created or modified to treat wastewater discharge from the airport, and although this pollution was halted finally in the 1980s, there are still legacy effects of this earlier enrichment (Smol 2023). All of the aquatic environments are underlain by benthic biofilms, typically dominated by cyanobacteria, but with diatoms, green algae and other taxa. The aim of this study was to characterize these benthic communities by HPLC pigment analysis, with associated chemical analysis of the overlying water. The study took place from 3 to 8 August 2021. The water for chemical analysis was obtained by grab samples near the shore, at the surface, and analyzed by standard methods at INRS, Québec. The benthic pigment samples were taken as 5 mm x 5 mm cores, that were then extracted as in Bonilla et al. (2005). Pigments were quantified in each extract by high-performance liquid chromatography (HPLC) as in Zapata et al. (2000). The biofilms sampled in this study have also been analyzed for bacterial community structure and antibiotic resistance genes (Provencher et al. 2024).