Effects of experimental sulfate additions on nutrient cycling, cyanobacterial abundance and mercury methylation in Lake 227, experimental lakes area

我们建议在安大略省西北部实验湖区的一个没有鱼的偏远湖泊--自1990年以来只接受磷的227号湖--添加全湖硫酸钠，以研究与富营养化管理、汞生物积累和道路盐影响有关的几个主要问题。我们假设，加拿大各地富营养化湖泊中不同的硫酸盐水平是湖泊反应中化学和生物变化的主要原因。该实验将考察(1)硫酸盐调节湖泊沉积物内部磷和铁负荷的程度，(2)控制有害蓝藻水华的形成，以及(3)硫酸盐调节甲基汞形成速率的程度。(4)本实验需要氯化钠(即道路盐)控制，因此一个实验将调查四个环境问题。

We are proposing a whole-lake sodium sulfate addition to a fishless, remote lake in the Experimental Lakes Area in Northwestern Ontario - artificially eutrophic Lake 227 which has received only phosphorus since 1990 to study several major questions related to eutrophication management, mercury bioaccumulation and road salt impacts. We hypothesize that varying sulfate levels in eutrophic lakes across Canada accounts for much of the chemical and biological variation in lake responses. The experiment will examine (1) the extent to which sulfate regulates internal phosphorus and iron loading from lake sediments which in turn, (2) control formation of nuisance cyanobacteria blooms, and (3) the extent to which sulfate regulates methylmercury formation rates. (4) This experiment requires a sodium chloride (i.e., road salt) control and thus one experiment will investigate four environmental problems.