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

通过大气沉积的汞污染是一个世界性的问题，新斯科舍省的湖泊也不能幸免。老矿井、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一些受温室气体污染最严重的水生生态系统。考虑到许多湖泊都有对人类和野生动物都很重要的关键鱼类物种，包括溪鳟、黄鲈和小嘴鲈鱼，这是一个令人担忧的主要问题。另一方面，新斯科舍省也有汞浓度低的偏远地区。新斯科舍省鱼类中汞含量的范围意味着这些湖泊可以被视为“试管”，以评估为什么某些湖泊的鱼类中汞含量高，而其他湖泊中汞含量低的假设。我的NSERC研究将弥合我们对全省汞食物网生物积累趋势的知识差距。首先，我们将研究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的汞生物放大：来自较高产（“绿色”）湖泊的鱼类食物网是否具有较慢的汞生物放大速率？其次，我们将评估酸雨在提高湖泊汞生物利用度方面的作用，以及湖泊沉积物中的硫酸盐浓度是否在决定食物网中汞被生物放大的程度方面发挥重要作用。第三，我们将比较有大量海水的沿海湖泊和有少量海水的山谷湖泊之间的差异，看看汞在两种类型的湖泊中是否以相同的速率生物放大。这些研究的结果是，我们将有更好的数据来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.