Lake Trouts are considered aquatic invasive species (AIS) in Montana. They have taken the role of being the top aquatic predator from the bull trouts in many large lakes west of the glaciers. This is affecting many native aquatic ecosystems since the lake trouts are feeding on the prey of other animals. This will cause the amount of prey to decrease as there are more predators eating and fighting for food. At first, the amount of lake trouts will increase but once the prey are all gone, the amount of aquatic species will start to decrease.