Anne-Marie Saint-Cerny has been a social and environmental activist in various NGOs for over thirty-five years. Videographer, essayist, and novelist, her book-length piece of investigative journalism Megantic, une tragedie annoncee (Editions Ecosociete, 2018) was in its original French edition the winner of the 2018 Prix Pierre-Vadeboncoeur, a finalist for the 2018 Governor General's Literary Awards for Non-Fiction, and was listed for the 2019 Prix des libraires.
Saint-Cerny participated in the launch of Fondation Rivieres, an NGO where she served as vice-president, then general manager, opposing private dams, the harnessing of the Rupert and Romaine Rivers, and campaigning for the preservation of vital watercourses.
Since 2008, acting as general manager of the Societe pour Vaincre la Pollution (SVP), she has been involved in several investigations on instances of ecological contamination by large corporations, notably the Lac-Megantic rail disaster and several Canadian mining projects. In 2018, she co-founded Quebec's Association des victimes de l'amiante (AVAQ). She was also present in Lac-Megantic during the full aftermath of the rail disaster and has supported the actions of victims and local committees since 2013. She was the Green Party's 2015 federal candidate for the riding of Hochelaga-Maisonneuve.