Fine cohesive erosion studies in the upper Bay of Fundy, New Brunswick

Abstract

My thesis examined erodibility of fine cohesive sediments at several intertidal mudflats in the upper Bay of Fundy, New Brunswick, Canada, related to air exposure time, sediment properties, and abundance of microalgal biofilm and the amphipod Corophium volutator. I also monitored changes at four nearby mudflats for one year after the opening of the Petitcodiac River Causeway gates. The Benthic Environment Assessment Sediment Tool (BEAST) was used to measure erodibility (erosion threshold and erosion rate). Sediment erodibility for emersion times up to 1 hour was unaffected. Higher Corophium densities were associated with more erodible sediments. I did not detect a significant effect of the causeway gates opening on erodibility of potentially impacted mudflats for up to one year after. My study highlighted relationships between sediment erodibility, Corophium abundance, and sediment conditions, providing baseline knowledge of sediment dynamics in intertidal mudflats and supporting future research in the Bay of Fundy.