For the future

Ducks Unlimited Canada (DUC) has big plans this month to restore a salt marsh on the Cornwallis River floodplain in the Annapolis Valley.

Conservation staff will be returning a freshwater marsh there, which sits adjacent to the river just outside Kentville, back to its historical origins as a tidal wetland.

The Duc-managed wetland, known as Cornwallis Marsh, and the tidal Cornwallis River are separated by an old agricultural dike. But during the past few years, as rising seas and more intense storm surges have lashed at coastlines, water in the salty river has started to eat away at the dike.

If left alone, the dike will quickly erode, and salt water will rush into the wetland, washing it and its critical wildlife habitat away too.

“Over the past few hundred years, we’ve lost 80 per cent of salt marshes along the Bay of Fundy and about 50 per cent of salt marshes across the province, so reclaiming where we can is a priority,” says DUC’S Nova Scotia conservation specialist Lee Millett.

The first step of the restoration is to excavate (or breach) the dike in three to four places. Earth removed from the dike will be placed inside the marsh and tamped down. Adding this extra soil, and keeping most of the dike in place at first, will help the marsh accumulate sediment, helping plant life grow.

Eventually the dike will completely wash away, but by then the restored salt marsh should be strong enough to withstand high tides and strong currents.

The second step is tracking how successfully the tidal wetland establishes. DUC works with universities and other researchers to monitor plant growth for years after a salt marsh has been restored, and this project will be no different. Data collected will help DUC and coastal communities better understand how to protect homes and vital ecosystems from rising seas.

“The marsh has been very productive in supporting waterfowl and other wildlife, but we can’t fight a rising ocean,” says Grenville Jones, Valley resident and a DUC director for Nova Scotia.

Salt marshes are important nurseries for smaller fish like gaspereaux and mummichog, which larger fish and crustaceans like striped bass and lobster depend on for food. They also capture and store carbon emissions, and buffer coastlines from erosion and flooding—which is becoming extremely important in the face of climate change.

“Restoring them is the right thing to do,” said Millett.