Evidence of cobble habitat preference in age-0 winter flounder, Pseudopleuronectes americanus

Abstract

Juvenile winter flounder utilize a wide variety of habitats, including those that are structurally complex. Although a common nearshore habitat in the Northwest Atlantic, selection of cobble habitat by juvenile winter flounder has not been the focus of previous study. In this laboratory experiment, we investigated habitat selection and preferences of age-0 winter flounder in sand and cobble of varying complexity. Fish were observed every 0.5 h for 6 h in tanks with four cobble treatments; bare sand, sand with low complexity cobble, sand with intermediate complexity cobble, and sand with high complexity cobble. Habitat preference was inferred when the proportion of observations in treatments were greater than what would be expected by chance based on availability. Results suggest that age-0 winter flounder strongly prefer cobble to sand, particularly cobble of an intermediate complexity. This study serves as a first step in the investigation of the importance of cobble habitat to juvenile winter flounder, and highlights the need for a more integrative approach when monitoring this species.