Paleolimnological tools for assessing the impact of road salt contamination on eastern Canadian lakes

由于冬季除冰盐在道路和其他基础设施上的应用而产生的径流导致淡水湖的盐污染，这是一个重大的环境挑战。这是加拿大东部的一个主要问题，自20世纪40年代以来，道路盐一直被广泛使用。岩盐（NaCl）是最常用的除冰剂，因为它具有成本效益，并且适合区域气候（有效至-18℃）。道路盐径流损害是累积的，随着湖泊盐度水平的增加，水生物种多样性和丰度下降，可能导致生态崩溃和水质改变。尽管NaCl的使用会对环境造成影响，但它的使用是可以容忍的，因为除冰可以显著减少（88%）道路交通事故和死亡人数。定期监测道路盐对水生群落和受盐破坏的饮用水供应的影响，对于充分了解这些污染物在环境中的途径和寿命，以及制定将环境恢复到干扰前（自然）条件的战略至关重要。这种监测费用昂贵，而且盐度测量每天可能有很大的波动，这可能影响结果。这项研究的目的是开发一种新的、广泛适用的、成本效益高的监测湖泊盐污染的技术，利用广泛存在于湖泊沉积物中的微小阿米巴原虫（有壳变形虫），这些生物已被证明对道路盐污染具有可量化的敏感性。该研究将首先关注大多伦多地区（GTA）湖泊的道路盐污染，该地区冬季道路盐使用量特别高（400系列公路220吨/公里，区域公路30吨/公里）。该研究项目的总体目标是：量化来自大多伦多地区和加拿大东部其他地区的大量湖泊中特定的Arcellinida分类群与关键的道路盐相关水性质和沉积物地球化学变量之间的关系；利用分布式数据集开发了一个可用于整个地区湖泊表层沉积物的arcellinidan盐污染指数（SCI），以对盐损害进行分类；并利用分布式SCI训练集，通过分析20世纪初至今的基线非道路盐影响条件的岩心，确定道路盐污染对湖泊生态系统的累积影响。提出的开发SCI的创新方法将导致一种经济有效的方法来评估盐污染对湖泊水生生态系统的累积影响。这些信息将有助于政策制定者和利益相关者战略性地管理道路盐污染的影响，并将有助于HQP的有价值的综合培训计划。

Salt contamination of fresh water lakes as the result of runoff from the application of winter de-icing salts to roads and other infrastructure presents a significant environmental challenge. This is a major issue in eastern Canada where road salt has been in wide spread use since the 1940s. Rock salt (NaCl) is the most commonly applied de-icer because of its cost effectiveness, and suitability for the regional climate (effective to -18C). Road salt runoff damage is cumulative, and as levels of salinity increase in lakes aquatic species diversity and abundances decline, which can lead to ecological collapse and altered water quality. Despite the environmental impact of the application of NaCl it's use is tolerated, as a result of deicing leading to a significant (88%) reduction in road accidents and fatalities. Regular monitoring of the impacts of road salt on aquatic communities and salt-damaged drinking water supplies is critical to gain a full understanding of the pathways and lifespan of these contaminants in the environment and to develop strategies to restore the environment to pre-disturbance (natural) conditions. Such monitoring is costly and salinity measurements may be subject to sizable daily fluctuations, which can influence results. The research aim is to develop a novel, widely applicable and cost effective technique of monitoring salt contamination in lakes, using microscopic Arcellinida (shelled amoeba), that are widely present in lake sediments, which have been shown to have a quantifiable sensitivity to road salt contamination. The research will initially focus road salt contamination on lakes in the Greater Toronto Area (GTA), where winter road salt application is particularly high (220t/km on 400 series highways and 30t/km on regional roads). The overarching objectives of the research program will be to: quantify the relationships between specific Arcellinida taxa and key road-salt related water property and sediment-based geochemical variables in a large set of lakes from the GTA and elsewhere in eastern Canada; use the distributional dataset to develop an arcellinidan Salt Contamination Index' (SCI) that can be readily applied to lake surficial sediments throughout the region to categorize salt damage; and use the distributional SCI training set to determine the cumulative impact of road salt contamination on lake ecosystems through analysis of cores spanning from baseline non-road salt impacted conditions of the early 20th century to present. The innovative approach proposed for development of the SCI will result in a cost-effective way to assess the cumulative impacts of salt contamination on lake aquatic ecosystems across the landscape and through time. This information will support efforts by policy makers and stakeholders to strategically manage the impact of road salt contamination, and will contribute to a valuable integrative training program for HQP.