In the mid-1990s, the Lake Saint-Pierre (Québec) population of yellow perch (Perca flavescens) started to undergo a sharp decline. By 2012, the situation had become so critical that the provincial government closed the commercial and sport fishing of this species. Although fishery activities contributed to the decline of yellow perch, this species has also suffered from habitat deterioration. An analysis of land-use using aerial photographs, coupled with modeling based on information concerning the best spawning habitat for yellow perch in the littoral zone, revealed that 5000 ha of spring habitat have been negatively modified by anthopogenic activities since 1950. Furthermore, the loss of submerged macrophyte beds, the proliferation of benthic cyanobacteria in the areas used by young yellow perch, the reduction in connectivity between the lake and the littoral zone, competition with exotic species, the arrival of a new avian predator and climate change have also contributed to poor recruitment and to the decline of the yellow perch. These findings suggest that the situation will only improve when this species is provided with a healthy environment in which to spawn and develop. This will require restoration of essential habitats, an improvement in water quality, and an enhanced level of connectivity between the lake and the littoral zone (including the floodplain).