The Nova Scotia Mercury Project: Quantifying environmental factors influencing biomagnification trends in aquatic food webs.

大气沉积造成的汞污染是一个世界性的问题，新斯科舍省的湖泊也不例外。老煤矿、燃煤发电厂的存在，以及独特的地质和湖泊特征，意味着新斯科舍省拥有北美汞污染最严重的一些水生生态系统。这是一个主要的问题，因为许多湖泊都有关键的鱼类物种，包括对人类和野生动物都很重要的小河鲑鱼、黄鳕和小口鱼。另一方面，新斯科舍省也有汞浓度较低的偏远地区。新斯科舍省鱼类中汞浓度的这种范围意味着，这些湖泊可以被视为评估为什么一些湖泊的鱼类汞含量高，而其他湖泊不高的假说。我的NSERC研究将填补我们对全省汞食物网络生物累积趋势知识的空白。首先，我们将看看由过量营养物质径流引起的湖泊中的藻类水平如何影响鱼类食物网中汞的生物放大作用：来自产量更高(“绿色”)湖泊的鱼类食物网汞生物放大速度是否较慢？其次，我们将评估酸雨对提高湖泊中汞的生物有效性的作用，以及湖泊沉积物中的硫酸盐浓度是否对确定有多少汞在食物网中被生物放大具有重要作用。第三，我们将比较暴露在大量海水中的沿海湖泊和海水很少的山谷湖泊之间的差异，看看汞在两种类型的湖泊中的生物放大速度是否相同。作为这些研究的结果，我们将获得更好的数据，了解汞在新斯科舍省各种湖泊中的行为。

Mercury contamination via atmospheric deposition is a world-wide issue, and the lakes of Nova Scotia are not exempt. The presence of old mines, coal-fired power generating plants and distinctive geological and lake features has meant that Nova Scotia has some of the most Hg-contaminated aquatic ecosystems in North America. This is of major concern given that many lakes have key fish species, including brook trout, yellow perch and smallmouth bass, important to both humans and wildlife. On the other hand, Nova Scotia also has remote sites with low concentrations of mercury. This range of mercury concentrations in fish across Nova Scotia means that the lakes can be viewed as "test tubes" to assess hypotheses to why mercury is high in fish from some lakes, but not in other lakes. My NSERC research will bridge the gaps in our knowledge of mercury food web bioaccumulation trends across the province. First, we will look at how algal levels in lakes caused by excess nutrient runoff can impact on mercury biomagnification in fish food webs: does the fish food webs from the more productive ("green") lakes have slower rates of mercury biomagnification? Second, we will be assessing the role of acid rain on enhancing mercury bioavailability in lakes and whether sulfate concentrations in lake sediments have an important role in determining how much mercury is biomagnified in food webs. Third, we will be comparing the differences between coastal lakes exposed to a lot of saltwater from the sea and valley lakes with very little saltwater and see if mercury biomagnifies at the same rates in both types of lakes. As a result of those studies, we will have better data on how mercury behaves in a wide variety of Nova Scotia lakes.