M-200B-2
Influence of the Submerged Aquatic Vegetation Landscape on Fish Larva Abundance

Monday, August 18, 2014: 3:40 PM
200B (Centre des congrès de Québec // Québec City Convention Centre)
Philippe Massicotte , Science de l'environnement, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
Andrea Bertolo , Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
Philippe Brodeur , Secteur de la Faune de la Mauricie et du Centre-du-Québec, Ministère du Développement durable, de l'Environnement, de la Faune et des Parcs du Québec, Trois-Rivières, QC, Canada
Christiane Hudon , Environment Canada, Montréal, QC, Canada
Marc Mingelbier , Direction de la Faune Aquatique, Ministère du Développement durable, de l'Environnement, de la Faune et des Parcs du Québec, Québec, QC, Canada
Pierre Magnan , Science de l'environnement, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
Submerged aquatic vegetation (SAV) creates functional habitats for aquatic organisms in both marine and freshwater ecosystems. By structuring habitats (fragmentation, patch size, complexity), SAV influences prey–predator interactions, population dynamics, community structure and ecosystem functioning. In freshwater ecosystems, the loss of SAV beds is occurring in many systems. Although many fish species occupy these habitats at some life history stage, the influence of the SAV landscape on their abundance has rarely been studied. We used yellow perch (Perca flavescens) as a biological model to evaluate the effect of the SAV landscape (characterized using satellite imagery) on the abundance of fish larvae in a large fluvial lake. After controlling for spatial autocorrelation among spawning grounds at a broad scale, we show that fish larvae are actively selecting SAV habitats after hatching. In habitats with low SAV biomass, the probability of observing perch larvae was approximately 20% and increased to nearly 100% in habitats with dense SAV (R2 = 0.54). Our results also suggest that larvae use both new vegetation as well as SAV debris from the previous year that persisted through the winter.