The main initiatives undertaken between 1978 and 2018 to identify and protect the habitat of the St. Lawrence Estuary (Québec, Canada) beluga whale (Delphinapterus leucas) population are presented. Despite these efforts, over the past 20 years, the state of the population has deteriorated. Not only is it declining, but the proportion of young has dropped to approximately a third of what it was, and female and calf mortality has risen. Recent information on the spatial distribution of beluga whales, their prey and marine traffic in the critical habitat in and around the Saguenay-St. Lawrence Marine Park are provided. Considerations and opportunities to develop spatial approaches to promote better cohabitation between human activities and beluga whales are given. In addition to the actions already undertaken, two strategies are outlined to promote recovery of the population: 1) the management of fisheries to account for the dietary needs of beluga whales and to prevent the resuspension of persistent contaminants by fishing gear; and 2) the reduction of disturbance due to disruption of vital activities, or through noise, in habitat used by females and young. Access to key prey and quiet areas in summer would improve the resilience of the population to degradations of its habitat, including those resulting from climate change.