Previous paleolimnological investigations have examined the effects of gold mining operations, local land-use changes, and regional climate warming on the aquatic biota from shallow lakes in Yellowknife, Northwest Territories, Canada. However, the long-term impacts of these multiple environmental stressors on the biota of deeper lakes that support large-bodied fish species have not been investigated. In this study, we examined multiple sedimentary proxies from two deep lakes around Yellowknife to assess the long-term effects of metalloid contamination, development of the city, and recent warming over the past ~ 200 years. The sedimentary metalloid profiles tracked the influence of mining operations and local land-use changes in the Yellowknife area and there were some similarities in the diatom responses to multiple stressors across the two lakes. However, the increases in sedimentary metalloid concentrations, eutrophic diatom taxa, and whole-lake primary production were more pronounced at Grace Lake relative to Alexie, likely because Grace is located nearer to the gold mines, as well as local city development. The overall lake primary production and the relative abundance of the planktonic diatom Discostella stelligera increased at both sites suggesting that some of the biological changes may be influenced by changes in thermal stratification, as has been documented in a wide spectrum of lakes across the Northern Hemisphere. Furthermore, the diatom assemblage changes in these deep lakes differed from those observed from shallow lakes in the region, suggesting that site-specific limnological characteristics will influence the biological responses to multiple environmental stressors through time.

中文翻译：

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区域金矿开采活动和最近的气候变暖改变了亚北极深湖中的硅藻组合

以前的古湖泊学调查研究了金矿开采作业、当地土地利用变化和区域气候变暖对加拿大西北地区耶洛奈夫浅湖水生生物群的影响。然而，尚未研究这些多重环境压力因素对支持大型鱼类物种的更深湖泊生物群的长期影响。在这项研究中，我们检查了来自耶洛奈夫周围两个深湖的多个沉积代理，以评估近 200 年来非金属污染、城市发展和近期变暖的长期影响。沉积类金属剖面跟踪了耶洛奈夫地区采矿作业和当地土地利用变化的影响，并且硅藻对两个湖泊的多种压力源的反应有一些相似之处。然而，与 Alexie 相比，Grace Lake 的沉积类金属浓度、富营养化硅藻类群和全湖初级生产力的增加更为明显，这可能是因为 Grace 更靠近金矿和当地城市发展。整个湖泊初级生产和浮游硅藻 Discostella stelligera 的相对丰度在两个地点都增加了，这表明一些生物变化可能受到热分层变化的影响，正如北半球广泛的湖泊所记录的那样。此外，这些深湖中的硅藻组合变化与该地区浅湖观察到的不同，