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).

梅雷塔湿地是一片广阔的浅水湖泊、池塘和溪流区域，主要汇入位于加拿大北极高地的科尔内利斯岛上的决绝湾地区的梅雷塔湖。该地区地形为极地沙漠，自20世纪50年代以来，由于机场和道路建设活动，地形发生了广泛的变化。至少部分流域是在此期间被开凿或改造，以处理机场的废水排放。尽管这种污染最终在20世纪80年代得到了遏制，但早期这种富集的遗留效应（Smol 2023）依然存在。所有水生环境均由底栖生物膜支撑，这些生物膜通常以蓝藻为主，但也包括硅藻、绿藻和其他类群。本研究旨在通过高效液相色谱（HPLC）色素分析对底栖群落进行表征，并对其上覆水进行相关化学分析。研究于2021年8月3日至8日进行。用于化学分析的水样是通过在岸边、水面进行现场采集获得的，并在魁北克省的INRS按照标准方法进行分析。底栖色素样本以5毫米×5毫米的芯样形式采集，随后按照Bonilla等人（2005）的方法进行提取。色素通过高效液相色谱（HPLC）进行定量分析，如Zapata等人（2000）所述。在本研究中采集的生物膜还进行了细菌群落结构和抗生素耐药基因的分析（Provencher等人，2024年）。