Population dynamics of the mudflat amphipod Corophium volutator in winter
University of New Brunswick
Winter conditions and their effects on population structure and behavioural responses of species remains understudied. The amphipod Corophium volutator is an abundant species inhabiting the intertidal mudflats of the upper Bay of Fundy. It is a well-studied species in summer, but little is known about how it is affected by winter, or its adaptations to winter. I studied population densities and structure of C. volutator, and biotic and abiotic variables at two representative mudflats (Grande Anse and Pecks Cove) over two winters between 2009 and 2011. I also investigated two possible adaptations of C. volutator to winter, its depth selection in the sediment and its low temperature tolerance. C. volutator densities declined linearly through winter, and no single biotic or abiotic variable could be implicated in driving that decline. In the depth selection study, most C. volutator individuals were located within 1.5 cm of the surface of the mud. In the temperature stress experiment, survival of C. volutator remained high at -3 °C, but declined at -8 °C. My research enhanced our understanding of winter conditions on mudflats in the upper Bay of Fundy, and of how C. volutator responds to those conditions.