EXPERIMENTAL TESTING OF WAVE TRANSMISSION COEFFICIENTS FOR OYSTER SHELL-FILLED BAG BERMS

Climate change and rising sea levels pose a significant risk of extreme flooding and erosion in coastal zones, requiring adaptation to make the shorelines more resilient. Berms composed of oyster shell filled-bags have been implemented at shorelines in western Canada (Provan et al., 2023) and in the United States (Milligan et al., 2018; Spiering et al., 2021; Wellman et al., 2021, among others) to provide a nature-based solution to reduce shoreline erosion or help stabilize restored salt marshes. However, there is limited available information on the performance and ability of these oyster shell berms in terms of wave attenuation. Previous experimental studies have been conducted to address this lack of information (Allen and Web, 2011; Coghlan et al., 2017); however, the studies were limited in tested wave conditions and sizes of the tested oyster shell filled-bags. To address this, a series of full-scale (1:1) physical model experiments were carried out to investigate the wave attenuation ability of oyster shell bags for different bag sizes and configurations.