A new map will give stakeholders in aquatic conservation insight on climate change by extending their view upstream

Every spring, juvenile Atlantic salmon migrate from rivers in Maine, Quebec and the maritime Provinces in Canada to the Atlantic Ocean, where they spend up to four years maturing before returning to the streams where they were born. Given climate change’s implications, these fish might soon be coming home to find different habitat from what they left behind.

“We will be dealing with warming waters and flooding events that will change flow rates, temperature, and more,” explained Margo Morrison, Director of Conservation Science for the Nature Conservancy of Canada.

For species like Atlantic salmon and Eastern brook trout that rely on specific temperatures to reproduce, climate change has serious implications for future populations. But in order to respond to emerging threats to aquatic habitat and species, scientists first need to address an existing challenge to protecting natural resources across broad geographies.

“There is no seamless classification of the aquatic environment across the border between the United States and Canada, or even within the Canadian portion of the North Atlantic LCC region,” explained Morrison.

That means partners trying to address parallel aquatic conservation issues on different sides of provincial and national borders are separated by more than just political boundaries. They are separated by incompatible maps and data.

Until now. With funding from the North Atlantic LCC, Morrison is overseeing a new project to develop a comprehensive classification and map of aquatic habitat across the Canadian portion of the North Atlantic LCC region, an effort that will break down a major barrier to protecting habitats that are defined by continuity.

The final product will be a classified spatial dataset of all hydrological systems within maritime Canada, consistent with the existing aquatic map that covers the U.S. portion of the North Atlantic LCC.

“The time for this project is now, both because of the changing circumstances, and because the data is becoming available,” explained William Millar, the project coordinator.  

Using GIS software, Millar will identify the individual watersheds within the entire network of rivers and streams across maritime Canada and Southern Quebec. Once the hydrological network and associated watersheds have been delineated, he will add in a set of distinct ecological characteristics - such as size, gradient, temperature, and tidal class - that can be used to classify every reach of every river and stream.

By providing a snapshot of all aquatic systems in the region as they stand now, the data will provide a baseline for measuring future changes.

“This is a huge first step, then going forward, we can use the information to identify watersheds that have unique or rare characteristics, watersheds that are highly degraded, and also ones that are in great shape,” said Morrison. “It will help organizations like ours see where the greatest needs lie, and respond to them more directly.

Millar pointed out that it will also help smaller organizations allocate scarce resources.

“Let’s say for example you are part of a watershed group,” he said. “If the headwaters of your focal watershed are in a different region, you can use this information to look at both upstream and downstream effects that can be factored into decision making and planning.”

In order to be sure the final product meets the needs of a range of partners, Millar is recruiting a diverse core team to guide the effort, including representatives from federal and provincial agencies, academic institutions, First Nations, conservation NGOs, and local watershed organizations. While the core team will be intimately involved with the analytical aspect of the project, he will also assemble an advisory group to provide ongoing feedback and a review of the final product.  

They will also seek technical input from the Eastern Division of The Nature Conservancy (TNC), which undertook the aquatic habitat classification and mapping for the U.S. portion of the North Atlantic LCC region. 

"Stitching together ecological data between Canada and the United States is so important for conserving freshwater systems, and making them more resilient in the face of climate change," said Arlene Olivero, who led the effort at TNC.

In terms of freshwater conservation, “It’s been a pretty hard border,” she said. “Now for the first time, we’ll be able to look at aquatic habitats that occur on both sides to see how they continue and compare across borders.”

The new project will complete more than just the aquatic picture; it is the one missing habitat link for the entire North Atlantic LCC region. In September, TNC completed project to extend the Northeast terrestrial habitat map into Canada as well.

“This is a great, natural progression,” said Millar. “It not only complements the terrestrial component, but allows for the interconnection between terrestrial and aquatic environments.”

For partners on both sides of the border, that will mean better prospects for species like salmon that are most vulnerable to landscape-scale threats, and have the most to gain from landscape-scale collaboration.