Roles of underwater soundscape and habitat characteristics on fish activity in a shallow lake during winter

Background/Question/Methods

Spatial heterogeneity in underwater ambient sound has shown to serve as a reliable indicator of habitat type and potentially convey habitat quality information to dispersing organisms. Fish communities’ structure and their relation with the habitat under the ice sheet during winter is still a subject poorly understood. In this context, assessing the spatial and the temporal heterogeneity in underwater ambient sound may prove a valuable tool. In our study, we examine the relationship between underwater ambient sounds, habitat physical and chemical characteristics and fish activity at a spatial and temporal scale, in a bay of Lake Saint-Pierre (St. Lawrence River, Quebec, Canada) during winter. Over two consecutive years, we conducted repeated surveys of underwater habitats and fish communities using tip-up fishing rods. We fitted generalized mixed models to disentangle the roles of both underwater acoustics and habitat characteristics on fish communities.

Results/Conclusions

Our results show that, in interaction with underwater hydrodynamics and surface conditions, ambient sounds are important descriptors of fish activity under the ice sheet, especially for yellow perch. Our work is seminal in studying the ambient soundscape of a shallow fluvial lake under the ice and its role regarding fish activity during winter. It conveys complementary information for fish population’s management and conservation, since overwinter fish endurance is crucial for fish population’s survival.