Sable Island is a small, low-lying, barrier-type island located 150 km off the east coast of Nova Scotia, Canada in the Northwest Atlantic Ocean (43.93oN, 59.91oW). Constantly shifting dunes and sandy beaches dominate the crescent shaped landscape. Referred to as the “graveyard of the Atlantic”, the island is associated with over 350 shipwrecks, which motivated its establishment as Canada’s first life saving station. The island is currently home to a unique ecosystem consisting of over 500 wild horses, endangered seabirds, and the world’s largest breeding population of grey seals. Sable Island was established as a Canadian National Park Reserve in 2013 due to its extensive human history and ecosystem. Further information on Parks Canada’s ecosystem management initiatives for the island can be found on their website. Funding from MEOPAR and Parks Canada supported our research on the vulnerable freshwater resources on Sable Island.

Sable Island’s ecosystem relies on freshwater sourced from precipitation that infiltrates into the highly permeable sands. This freshwater is stored in a lens shaped zone of fresh groundwater that floats above denser seawater. The freshwater lens intersects the land surface in topographic depressions and forms small ponds that support the island’s wildlife. The recent decline or disappearance of these critical ponds raises questions about the future of the island's freshwater and ecosystem.

Waves and tides batter the island's coast, and hurricanes and other storms cause extensive seawater flooding on the island's beaches. Coastal flooding has the potential to salinize the island's surface and subsurface freshwater resources. The remote location of Sable Island and observations of declining freshwater provided the motivation to establish a near real-time wireless monitoring network. Our lab has been studying Sable Island since 2018, and related open-access journal publications in 2023 and 2024 highlight the impacts of coastal storms, erosion, and sea-level rise on the fragile freshwater lens.

The Dalhousie Coastal Hydrology lab deployed and maintained an inexpensive wireless sensor network that enables near real-time ocean and hydrologic monitoring using wave buoys and pond and groundwater sensors. The monitoring system will be valuable to island stakeholders and will make Sable Island remotely accessible. 

In September 2022, we installed a Campbell Scientific (and RiOT technology) wireless sensor network for real-time monitoring in three surface water ponds. The control system was deployed on the West Lighthouse (below, left). A specialized data logger sends commands to "motes" (top right) that control sensors installed in the ponds (bottom right) to monitor temperature, water level, and electrical conductivity (salinity). A specialized satellite transmitter wirelessly sends the data to the GOES satellite system where it is integrated and plotted on our Campbell Cloud website. On this dashboard (at this link, if needed, click on the dashboard symbol on the upper left) you can view recent climate data (air temperature and relative humidity) and the levels, temperatures, and conductivities (proxy for salinity) of the three ponds.

Our research on Sable Island was primarily funded through a MEOPAR Early-Career Award and a MEOPAR Knowledge Mobilization Grant. The latter grant (2020-2022) was focused on developing a wireless sensor network on Sable Island to make this new National Park Reserve more accessible for Canadians. We have also worked closely with Parks Canada Agency with funding to support development of a 3D groundwater model of the island. The wave buoys have been installed in partnership with the Ocean Frontier Institute and the Ocean Tracking Network.