Not only did changes occur in the atmosphere, they also occurred in the water. The creation of the reservoir compromised the livelihood of aquatic life, which before the dam lived peacefully in the river. Rivers and lakes support different species therefore some fish were able to thrive in the lake but others could not be supported by its different environment. Mountain whitefish, rainbow trout and Arctic grayling were primarily the species that faced decline. A number of species were known to have thrived and it is estimated that there are more fish in the basin today than before the reservoir, but possessing levels of mercury indicating they are not entirely healthy. High levels of mercury have been measured in the lake, as a result of decaying matter from the plants and trees that drowned. Mercury is released into the lake, is ingested by tiny organisms and eventually makes its way up the food chain. In 2000 British Columbia issued a Fish Consumption Advisory for bull trout and dolly varden warning people about the high content of mercury in these fish.