Modeling the Impact on Sediment Texture of Large-Scale Tidal Power in the Bay of Fundy

Abstract

The output of a 3-D ocean circulation model and information on nearly 10,000 sediment samples are used to examine the extent to which a model of ocean currents can be used to predict seabed sediment texture in the Bay of Fundy and Gulf of Maine. It is found that sediment texture is generally closer to equilibrium with maximum tidal bed shear stress in the Gulf of Maine than in the Bay of Fundy. In the Bay of Fundy, competent mean grain sizes are generally coarser than observed mean grain sizes, and further interpretation suggests that sediment supply has a dominant influence on texture. Furthermore, the impact on texture is predicted for two tidal power development scenarios in the Minas Passage (Hasegawa et al., 2011). For a 2.0 GW of power scenario, a sediment fining is predicted in parts of Minas Passage, although the impact should be small as supply dominates texture. Further research is needed to quantify with more precision the potential impact of tidal power development on texture, especially in the Bay of Fundy.