Lake sediments and legacy environmental stressors

我的研究项目将使用水生沉积物和其他关键的流域措施，研究湖泊如何随着时间的推移对环境变化作出反应。加拿大人类活动造成的遗留污染对许多淡水生态系统，包括其食物网造成了破坏。虽然观察到生态系统恢复的迹象，但由于人类活动，许多湖泊现在经历着多种共同发生的环境压力。理解环境变化往往需要一个长期的时间观，因为它往往是在几十年内逐步发生的。从加拿大沿海省份的两个有据可查的污染例子中恢复湖泊，林业中使用的杀虫剂和金矿开采中的污染物，将是我未来五年研究计划的重点。这些广泛的化学品和（类）金属污染的例子与过去发生类似活动的加拿大其他地区有关。了解沉积物污染的影响以及湖泊恢复的方式对于评估水生健康、识别风险和制定受污染生态系统的补救计划非常重要。我们将使用无脊椎动物和地球化学签名保存在过时的沉积物芯调查污染趋势和当代的压力，如气候变化和土地利用，可能会影响整个世纪到现在的湖泊生态恢复。地球科学和水生科学的共同方法将用于确定环境变化的时间，以及相对于"基线"或典型水生条件的影响。我们的方法提供了关于温带湖泊生态系统如何从严重污染中恢复的新知识，同时也面临着现代环境压力。

My research program will use aquatic sediments and other key watershed measures to study how lakes respond to environmental change over time. Legacy pollution from human activities in Canada has resulted in damage to many freshwater ecosystems, including their food webs. Although signs of ecosystem recovery are observed, many lakes now experience multiple, co-occurring environmental stressors because of human activities. A long-term time perspective is often needed to understand environmental change because it tends to occur incrementally over many decades. Lake recovery from two well-documented examples of pollution in the Maritime provinces of Canada, insecticides used in forestry and contaminants from gold mining, will be the focus of my research program over the next five years. These examples of widespread chemical and metal(loid) pollution have relevance to other regions of Canada where similar activities occurred in the past. Understanding sediment-bound pollution impacts and how lake recovery occurs are important to assessing aquatic health, recognizing risk, and developing remediation plans for polluted ecosystems. We will use invertebrates and geochemical signatures preserved in dated sediment cores to investigate pollution trends and how contemporary stressors, such as climate change and land use, may influence the ecological recovery of lakes across the 20th century to the present. Methods common to geoscience and aquatic science will be applied to determine the timings of environmental changes, and their impacts relative to "baseline" or typical aquatic conditions. Our approach provides new knowledge on how temperate lake ecosystems may recover from severe pollution while also facing modern environmental stressors.