B.C. fish are making a splash after newfound freedom
Physical barriers can prevent fish from accessing habitat needed for all stages of their life cycle, a prevalent issue in B.C. that prompted the provincial government and conservation groups to step in to resolve.
Fish are getting a helping hand to thrive in British Columbia, thanks to restorative efforts from the provincial government and environmental organizations.
Since 2020, the Canadian Wildlife Federation (CWF) has supported 13 B.C. barrier-removal projects for fish passages. To highlight its ongoing progress, the organization released videos in March for two of its current projects. They cover the migration of fish on the traditional territories of Lake Babine Nation and Takla Lake First Nation in the northern Interior.
SEE ALSO: How wildlife corridors can reconnect Canada's fractured habitats
According to CWF, human-made barriers prevent fish from accessing habitat needed for all stages of their life cycle. Different types of habitat are needed for accessibility in all seasons and life stages, with connected waterways being essential for them.
Nicolas Lapointe, CWF senior conservation biologist of freshwater ecosystems, told The Weather Network that fish passage restoration is an area "we really wanted to work in" because the provinces have had ample leadership in planning and addressing the movement issues.
(Avison Management Services Ltd.)
"We're really impressed with what they did, and we wanted to learn from them and build on that work," said Lapointe.
NUMEROUS BARRIERS TO FISH AND THEIR IMPACTS
Migratory fish, including species that travel between oceans and freshwaters (diadromous) and those that trek within freshwaters (potamodromous), are particularly reliant on moving freely through rivers, streams and lakes without obstruction.
CWF has focused its removal efforts on barriers that have "good datasets," Lapointe said, including smaller-sized dams with water control structures and any road or rail crossings, if they aren't bridges with open structures beneath, as they will limit fish movement.
He acknowledged that some culverts "hold up for a good amount of time if they're properly designed and installed," but most aren't. As well, there are natural and semi-natural barriers such as landslides and slugs of sediment, plus other river material that have ended up in the streams.
(Avison Management Services Ltd.)
The impacts of barriers on fish populations depend on the species, Lapointe noted. For example, they could have serious ramifications for Pacific salmon, which have to migrate between freshwaters and the ocean to complete their life cycle.
"If you've got a barrier that cuts them off from their spawning habitat, you're going to lose that portion of the population that existed above that barrier. That's kind of the absolute worst-case scenario," said Lapointe.
However, he pointed out that if the fish can complete their entire life cycle within smaller reaches of stream on either side of a barrier, then you won't necessarily lose the "full" population, but you do lose the connectivity between those populations.
"Different life stages of fish need different types of habitats to survive. By reconnecting those river escapes and allowing fish to move freely throughout them, you're able to let them get to the habitats they want to be in and succeed the most in over time," said Lapointe.
VARIOUS HABITATS RESTORED
Sitlika Creek, a tributary to Takla Lake, was thought to have supported an at-risk population of sockeye salmon before a rail line was built in the 1950s, according to CWF.
(Jim Trask/Cornice Environmental Consulting Ltd.)
Habitat in Sitlika Creek is a suitable home for sockeye salmon, kokanee and rainbow trout, among other species. CWF then partnered with the Takla Lake First Nation and Canadian National Railway Company (CN Rail) to develop a new, open channel through the rail line right-of-way and eliminate the culvert from the stream. As a result, this created access to three kilometres of pristine spawning and rearing habitat.
"Because the rail lines weren't being used, we eventually decided to take them out entirely and restore the stream. Takla Lake First Nation was really happy to have that done," said Lapointe. "It was a good first working relationship between CWF and CN [Rail]."
Betty Rebellato, improvement co-ordinator for CWF’s National Fish Passage Program, told The Weather Network that it is a "really quite an exciting project," especially now that CWF is beginning to examine how rail lines are impacting fish habitat across B.C. on a larger scale.
(Tyler Wood/B.C. Ministry of Forests)
Another waterway that's been the focus of restoration work is Cross Creek, a tributary to Babine Lake. It provides spawning habitat to native Babine sockeye salmon, along with coho salmon, kokanee and rainbow trout.
Rebellato noted that the creek contained a set of culverts that were rotting underneath the road, prompting restoration work from CWF, Spruce City Wildlife Association and the Ministry of Transportation and Infrastructure. Lake Babine Nation, which monitors all the streams around Lake Babine, noticed the fish were unable to pass through.
"It's kind of a bit of a learning process on our part, as well. They're teaching us how they go about these remediation projects, and we were giving input and support in any way that we could as that went through," said Rebellato.
After a habitat is freed from blockage, she said the organization can measure roughly how much of it has reopened once access is restored.
FISH PASSAGE: CROSS CREEK
CWF was told by Lake Babine Nation that approximately 2,200 salmon were able to swim past the barrier in Cross Creek in the summer the restorative work on the waterway was finished.
"That was really encouraging to see again," said Rebellato. "I still think that's a win, regardless of what would have been there beforehand that could have gone up there."
Another "immediate clear win" was the observation of chum salmon above the Nelson Creek fish ladder and after a forestry log jam was removed from MacKenzie Creek. The latter resulted in the documentation of sockeye salmon within an hour after clearing the barrier, Lapointe added.
OBSTACLES FOR FISH PASSAGES FOUND ACROSS THE COUNTRY
It isn't just in B.C. where fish have a difficult time navigating passages due to barriers. The obstructions can be found across the country, something CWF is highlighting as it is currently building a national database of all barriers blocking fish.
The organization is currently in the final months of completing the first phase, which will map out all the dams, waterfalls and fishways in Canada.
(Betty Rebellato/CWF)
Lapointe noted that CWF has identified 40,000 dams in Canada, but less than 400 fishways. This translates to less than one per cent of the dams in the country having fish passages around them.
"We really are behind the times in terms of a culture change and how we manage our freshwater ecosystems in Canada," said Lapointe.
Thumbnail courtesy of Avison Management Services Ltd.
Follow Nathan Howes on Twitter.