See the attached quick identification sheet for Invasive Aquatic Plants.
Invasive species are plants, animals, and micro-organisms that, when introduced outside of their natural environment, out-compete native species (Government of Canada, 2016). Invasive species can have harmful consequences for the natural environment, economy, and society, including human health. However, not all introduced species are invasive. Some, like the introduced Chinook salmon (Oncorhynchus tshawytscha), produce economic incentives for society, while also not posing a significant threat to native fish and their ecosystems.
Invasive aquatic plants, by contrast, displace native vegetation, slow down water flow, alter oxygen levels, and can affect recreational activities (e.g. boating, fishing, and swimming).