Estuaries and coastal marshes make up less than three percent of British Columbia’s coast—but they are rich habitats that support 80 percent of the province’s fish and wildlife species. Not only are these areas a vital source of food for Indigenous peoples, they are magnets for migratory birds, rearing grounds for salmon and other fish, and lush banquets for seals, otters, eagles and grizzly bears. Estuaries also shield the coast from erosion and storm damage, and filter out pollution, helping to keep waterways clean.
As with so many ecosystems, estuaries face mounting pressure from the effects of climate change. For the past five years, Tula’s Hakai Institute has been part of a collaborative effort to understand climate change impacts on British Columbia’s coastal marshes and estuaries through the Estuary Resilience Project (ERP).
Led by the Nature Trust of British Columbia and coastal First Nations, the ERP has brought 12 different nations and tribal councils together with university researchers, the federal and provincial governments, and NGOs—an alliance based on concern for the ecosystems that are woven into British Columbia’s cultural fabric.
“It all comes back to the salmon for me,” says Jared Dick, a regional fisheries biologist with the Nuu-Chah-Nulth Tribal Council. “I grew up relying on salmon, fishing salmon. I remember pulling a net since probably the first time I could walk, and working to protect our food source is just what gets me out of bed.”
Researchers interpret the gathered data through an innovative tool that Tom Reid, West Coast Program Manager with the Nature Trust of British Columbia, first encountered at a 2015 conference on estuaries in Portland, Oregon. Developed in the United States, MARS (Marsh Resilience to Sea-Level Rise) is used to evaluate an estuary’s vulnerability to predicted sea level rise over the coming years.
Partners have spent a lot of time in gumboots and chest waders measuring sediment accretion rates, turbidity, and tidal variation at 15 estuary sites in British Columbia, from Bella Coola on the Central Coast to the Cowichan Estuary on southern Vancouver Island.
“You get close to people when you spend time in the field together, whether it's a sunny day or a rainy day,” says Jonathan Moore of the Salmon Watersheds Lab at Simon Fraser University, who has been involved in the ERP since it began. “Hauling in a net together shoulder to shoulder, you build those connections.”
Evaluating resilience will give First Nations and coastal communities in the study areas a chance to determine what interventions might be needed to increase resilience and prevent the estuarine habitat from drowning. In the Cowichan Estuary, ERP research has led to plans to restore 70 hectares of marsh by removing human-made barriers and reconnecting freshwater channels to tidal zones.
“We don't want to get to the point of people saying, ‘How come there are no chinook in the Cowichan River anymore?” says Reid.
The ERP was made possible by British Columbia Salmon Restoration and Innovation Fund grants, and in February, the United Nations endorsed the project as part of the UN Decade of Ocean Science for Sustainable Development. Since its launch in 2019, the project has relied on partners bringing forward traditional local knowledge as well as contemporary sampling and testing technology. The Hakai Institute’s infrastructure and support, says Reid, were critical pieces that allowed the partners to manage all the data in order to use the MARS tool effectively.
“Collaboration really strengthens science,” says Jonathan Moore. “It means that it is built by the folks that know that place the best. I like to think of science arising from place and people; it comes out of the local expertise and what the needs are of that place, rather than getting imposed from outside.”
You can learn more about the project in this video produced by the Hakai Institute and the Nature Trust of British Columbia.
