Located in the lower reaches of the catchment, Montrose Basin Local Nature Reserve, and the surrounding land, is highly susceptible to infestation from invasive non-native species whose seeds have arrived from upstream. Parts of the reserve, along the banks of the river as it approaches the estuary, have been smothered with Himalayan balsam.

Over the course of several years Scottish Wildlife Trust ran an intensive programme of targeted control, with volunteers spending approximately 100 hours per season removing Himalayan balsam. Cleared banks allowed native plants to quickly regenerate.