The Mute Swan is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) and the RAMSAR Convention of 1972 protections apply. However,numbers fluctuate, due to die-offs caused by pollution, degraded lead in water bodies, installation of towers, high wires and loss of habitat due to development. A massive die-off of waterfowl, including swans, came in 1926 when the U.S.War Department tested phosphorus bombs in the Baltimore Harbor, emptying into the Chesapeake Bay.

The Mute Swan is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) and the RAMSAR Convention of 1972 protections apply. However,numbers fluctuate, due to die-offs caused by pollution, degraded lead in water bodies, installation of towers, high wires and loss of habitat due to development. A massive die-off of waterfowl, including swans, came in 1926 when the U.S.War Department tested phosphorus bombs in the Baltimore Harbor, emptying into the Chesapeake Bay.