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Dalhousie Engineering Professor working to protect Sable Island's ecosystem

Posted by Engineering Communications on February 20, 2019 in News
Dr. Barret Kurylyk's research aims to protect the water resources that Sable Island's horses depend on.
Dr. Barret Kurylyk's research aims to protect the water resources that Sable Island's horses depend on.

For generations, Sable Island has intrigued Canadians and much of North America.

The crescent shaped landscape spans for miles across the Atlantic ocean and sits 300 km southeast of Halifax. The island is famously home to an estimated 500 wild horses, as well as the world's largest breeding colony of grey seals; it is also the location of Dr. Barret Kurylyk’s next research project.

Kurylyk, a hydrologist and assistant professor in Dal’s Faculty of Engineering, is studying how to better protect the island’s unique freshwater resources and the ecosystem that depends on them. He is currently expanding the project based on new funding through the MEOPAR Early Career Award.

Dr. Kurylyk joined Dal’s Department of Civil and Resource Engineering in July of 2017. His research focuses on a range of coastal groundwater quantity and quality issues including how hydrologic systems respond to environmental changes and the interactions between aquifers and surface water bodies.

This spring Kurylyk and his team will focus on Sable Island’s rapidly shrinking fresh water ponds: the only source of fresh drinking water available on the island.

“The volume of fresh surface water has shrunk by over 50 per cent in the past few decades. That’s a drastic decline in fresh water resource on Sable Island,” reports Dr. Kurylyk.

Water is especially limited on the eastern side of the island.

“On parts of Sable Island where the horses no longer have fresh water ponds, they have to dig into the sand to access water,” he continues, “That means they’ll dig holes until they hit the groundwater table and then they’ll drink from that.”  

Kurylyk says because of the high rates of high tides and storm surges along the island, significant volumes of salt water intrude into the ponds and freshwater aquifer.  

“There are two types of saltwater contamination that can occur along coastal lines,” Dr. Kurylyk notes. “Over time, as climate changes and sea levels rise, you can have a gradual lateral salinization of these fresh water ponds.”

 “But on top of that,” he adds, “you can also have sudden episodic events where storm surges come in on the island and you have salt water going down into the aquifers from above.”

Once on Sable Island, Kurylyk will install shallow monitoring wells with conductivity loggers that will analyse how ocean tides, storm surges and hurricanes influence the salinity of ponds and shallow aquifers.

“On small islands, there is a freshwater aquifer (called 'a freshwater lens') that effectively floats above the denser seawater. We can measure the depth to the saltwater (which is typically 10's of meters) using geophysical instruments that discriminate between zones of different conductivities.”

Kurylyk’s research findings will be particularly valuable to Parks Canada as Sable Island was designated as a National Park Reserve in 2013.

Fewer than two hundred and fifty people visit the island each year, but that number may increase if Parks Canada opens its beaches to the public.

“If there’s going to be more people on the island in the future, which some are discussing, there could potentially be more demand for fresh water supply,” he says. “Regardless, the present rate of decline in freshwater is not sustainable.”