Centre for Earth Observation Science (CEOS), University of Manitoba, Winnipeg, Canada.
Northern Environmental Consulting, Pinawa, Manitoba, Canada.
Sci Total Environ. 2023 Jan 10;855:158718. doi: 10.1016/j.scitotenv.2022.158718. Epub 2022 Sep 13.
Hudson Bay is a small arctic inland shelf sea which receives large amounts of freshwater from riverine discharges, with marine flow from the north and the Atlantic. A warming climate has resulted in an expanded open water season which will result in an increase in shipping of fuel oil and petroleum to communities and mines on the western shore, increasing the risk of hydrocarbon releases. To evaluate the status of hydrocarbons, surface sediments were collected at 34 locations in the transportation route and offshore and analysed for several types of hydrocarbons. Total hydrocarbons varied by over 25 times between sites, reaching a maximum of 1116 μg/g OC (organic carbon basis) in Hudson Strait due to low molecular weight n-alkanes from marine primary production. The gross mean for all sites was 344 μg/g OC (GSD = 173-682), roughly equivalent to other remote sites in the Canadian Arctic with no known local hydrocarbon source. n-alkanes accounted for >90 % of residues. Diagnostic ratios (e.g., Carbon Preference Index (CPI), Odd-Even Predominance (OEP)) indicated mixed sources of n-alkanes, likely due to the input from vascular plants and ombrotrophic peat in northern and western watersheds, and primary production within the Bay. The elevated proportion of high molecular weight n-alkanes at deep water sites is consistent with lotic particulate organic matter deposited in the nearshore environment and redeposited offshore. ƩPAHs were a small fraction (1.9 %) of hydrocarbons, with a gross mean of 5.68 μg/g OC (GSD = 3.30-9.79). PCA separated deep water sediments from nearshore and community samples due to 4 alkylated naphthalenes which usually indicate a petrogenic source but probably indicates a natural source due to the lack of other petrogenic markers. Priority PAHs (i.e., ƩPAH) varied from 31.5 % to 56.6 % of the ƩPAH residues. The concentrations of individual PAHs were well below the Interim Sediment Quality Guidelines recommended by the Canadian Council of Ministers of the Environment.
哈德逊湾是一个小型的北极内陆架海，从河流排放中接收大量淡水，并有来自北方和大西洋的海洋流。气候变暖导致开阔的通航季节扩大，这将增加向西海岸社区和矿山运输燃料油和石油的数量，增加碳氢化合物泄漏的风险。为了评估碳氢化合物的状况，在运输路线和近海的 34 个地点采集了表层沉积物，并对几种类型的碳氢化合物进行了分析。由于海洋初级生产产生的低分子量正构烷烃，各地点之间的总碳氢化合物差异超过 25 倍，在哈德逊海峡达到最大值 1116μg/g OC（有机碳基础）。所有地点的总平均值为 344μg/g OC（GSD=173-682），大致相当于加拿大北极地区其他没有已知本地碳氢化合物源的偏远地区。正构烷烃占残留物的>90%。诊断比（例如，碳优先指数（CPI）、奇偶优势（OEP））表明正构烷烃的混合来源，可能是由于北方和西部流域的维管束植物和腐殖质泥炭以及湾内的初级生产输入所致。深水地点高分子量正构烷烃比例升高，与近岸环境中沉积的流水颗粒有机物质以及近海重新沉积的物质一致。ƩPAH 仅占碳氢化合物的一小部分（1.9%），总平均值为 5.68μg/g OC（GSD=3.30-9.79）。由于通常表示石油源的 4 种烷基化萘，PCA 将深水沉积物与近岸和社区样本分开，但由于缺乏其他石油源标志物，可能表明这是一种自然来源。优先 PAH（即ƩPAH）占ƩPAH 残留物的 31.5%至 56.6%不等。个别 PAH 的浓度远低于加拿大环境部长理事会建议的临时沉积物质量指南。
