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

由于在道路和其他基础设施中使用冬季除冰盐而产生的径流造成淡水湖的盐污染，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，道路盐在那里得到了广泛的使用。岩盐(氯化钠)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摄氏度)。道路盐分径流的损害是累积的，随着盐度水平的增加，湖泊中水生物种的多样性和丰度下降，这可能导致生态崩溃和水质变化。尽管使用氯化钠会对环境产生影响，但它的使用是可以容忍的，因为除冰可以显著减少(88%)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路径和寿命，以及制定将环境恢复到干扰前(自然)条件的战略至关重要。这种监测费用高昂，盐度测量可能会受到相当大的每日波动的影响，这可能会影响结果。*研究的目的是开发一种新的、广泛适用的、具有成本效益的湖泊盐分污染监测技术，使用广泛存在于湖泊沉积物中的微型Arcellinida(贝壳变形虫)，已被证明对道路盐分污染具有可量化的敏感性。这项研究首先将重点放在大多伦多地区(GTA)的湖泊上，那里冬季道路盐的使用量特别高(400系列高速公路上的220吨/公里，区域道路上的30吨/公里)。该研究计划的总体目标将是：在GTA和加拿大东部其他地方的一大批湖泊中，量化特定的Arcellinidas分类群与关键的与道路盐分相关的水属性和基于沉积物的地球化学变量之间的关系；使用分布数据集来制定Arcellinidan盐分污染指数(SCI)，该指数可以很容易地应用于整个地区的湖泊表层沉积物，以对盐害进行分类；并使用分布的SCI训练集，通过分析从20世纪初到现在的基线非道路盐分影响条件的岩心，来确定道路盐分污染对湖泊生态系统的累积影响。*为开发SCI提出的创新方法将产生一种成本效益高的方式，以评估盐污染对整个景观和时间的湖泊水生生态系统的累积影响。这些信息将支持政策制定者和利益相关者从战略上管理道路盐污染影响的努力，并将有助于为HQP提供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.**