HYDRODYNAMIC FORCING AND EROSION DYNAMICS ON TWO SMALL ISLANDS OFF THE NORTH SHORE OF PRINCE EDWARD ISLAND: A BASELINE ASSESSMENT

Abstract

The global mean sea level (GMSL) is currently rising and continues to accelerate, in large part due to thermal expansion and a loss in land-ice mass, making low-lying coastal communities and small islands vulnerable to climate change and sea-level rise (SLR). Atlantic Canada’s coastal region has been and will continue to be significantly impacted by SLR in the following century, which will increase existing flood and erosion risks along the region’s coastline. As small islands are vulnerable to climate change, the north shore of Prince Edward Island (PEI) and its sandy barrier island system is an ideal location to study island vulnerability to climate change. Lennox Island, located in Malpeque Bay off the north shore of PEI, is home to the Lennox Island Mi’kmaq First Nation and has been an area of growing concern for climate change and coastal erosion risks. Hog Island functions as a protective barrier to mitigate the impacts of future coastal storms in Lennox Island and surrounding Malpeque Bay, is culturally and historically important to the Mi’kmaq population, and is being established as a national park reserve. Overall, this study focused on monitoring hydro- and morphodynamics of the area to establish a dataset of environmental conditions from which to quantify future changes and to conduct first order assessments for predicting coastal recession and wave dynamics. More specifically, the coastal currents and wave propagation around Hog Island and into Malpeque Bay were investigated; the wave attenuation impacts of a newly forming oyster reef near the shore of Lennox Island were assessed; and drone-based surveys were used to monitor morphological change on both Hog Island and Lennox Island. This was accomplished using state-of-the-art technology paired with data analysis and first-order interpretations using the Bruun rule and the Bretschneider equation. Collectively, these wave, sediment, and digital elevation model data form a dataset for assessing future environmental change (forcing and response) on Hog Island and Lennox Island. This is critical in the context of sustainable and proactive decision making for the Lennox Island First Nation and recent progress in establishing a federal national park reserve and Mi’kmaq Heritage Landscape on Hog Island, Pituamkek National Park Reserve.