Man relies on swans, especially Mute Swans, to alert to problems in the environment, such as the presence of heavy metals (copper, lead and mercury), as well as harmful microorganisms. Mute Swans have also been shown to promote biodiversity in the environment by allowing certain species such as dabbling ducks to feed from sub-aquatic vegetation and macrophytes that they would not otherwise be able to eat it if were not for the Mute Swans bringing the food resources to the top of the water.

Swans of all species rely on man to maintain clean wetlands and other water habitats and to provide safe areas from hunting, fishing, boating, development and other human encroachment. The Regal Swan