Dozens of birds have died and others are seriously ill following an outbreak of botulism in several lakes across the Perth area.

WA Seabird Rescue spokeswoman Fiona O'Sullivan said outbreaks had been identified in Kardinya, Mandurah and Lake Claremont, and the group had removed more than 50 dead birds in the past week alone.

She said the organisation was expecting other affected areas to be identified in the upcoming days.

WA Seabird Rescue spokeswoman Fiona O'Sullivan is urging people to keep an eye out for botulism infected birds. Credit:Kim Frost

Botulism is a bacterial disease that causes a gradual paralysis of body muscles.