Flyfishing for steelheads. photo credit Dec Hogan

The tiny Craig Creek flows from a massive expanse of forest through the Saugeen First Nation, into the Saugeen River, and from there into Lake Huron. Compared to these massive bodies of water, Craig Creek seems insignificant. But the seemingly unimportant creek serves an ecological function: Steelhead Trout from Lake Huron and the Saugeen River swim up Craig Creek to access a key spawning area. And on their journey up the creek, the fish try to swim through a culvert.

A culvert is a watercourse structure, often a corrugated pipe, that enables water to flow under a road or railway from one side to the other without eroding the infrastructure. Culverts are a frequent method of enabling cars and trains to pass over ditches, streams, and rivers. However, over the past half century, culverts were often engineered and installed to ensure the stability of roads and railways, while less attention was paid to their effect on fish habitat.

Fish migrate through lakes, rivers, and wetlands during different stages of their life. However, fish often can’t complete their journey when they encounter poorly engineered watercourse structures like culverts, barriers that threaten their ability to feed and reproduce. As a consequence, some fish species in Canada have experienced population decline and some have even gone extinct.

Since the late 1990s, many civil engineers, like Jason Duguay of the University of Sherbrooke, have recognized the importance of fish passage. Duguay recently helped test a new baffle that facilitates fish passage and that baffle was recently sliplined into the culvert on Craig Creek. With more projects like this in the pipe, Duguay expects to work for many years redesigning and repurposing problem culverts.

However, the Steelhead that migrate up Craig Creek are an invasive species that actually pose problems for native species and the Saugeen First Nation. The First Nation was obligated to repair the culvert in part due to changes in 2012 to the Fisheries Act.This raises challenging questions about how we prioritize protecting some habitats and species over others, and while trying to balance conflicting ecological and human interests. 

A dual-pipe culvert bridge. Photo credit Pi-lens

Protecting fish habitat is both an ecological and social concern. Many First Nation communities depend on fish for their livelihood, a way of life they have enjoyed for thousands of years and has been affirmed in Canada’s constitution. The situation on Craig Creek demonstrates how innovation, like a well-engineered culvert, can only be effective if guided by enlightened policy.

According to a report from Canada’s Department of Fisheries and Oceans, poorly engineered culverts create five major stressors for migrating fish. First, they create flow velocity that can be so fast that fish exhaust their energy and fail to make it through. Second, poorly engineered culverts can create turbulence in the water; the same way air turbulence tosses around an airplane, water turbulence tosses fish about and can exhaust or injure them. Third, many culverts become perched (i.e., the culvert develops a fall at the outlet), making it difficult or impossible for fish to even enter the culvert. Fourth, problem culverts can lack the pool depth fish need to swim. Finally, most culverts lack resting spots with lower velocity and turbulence where fish can re-gather their strength and continue swimming upstream. These five impediments pose a significant barrier to migrating fish.

The problem culvert at Craig Creek. Photo credit MTO

Jason Duguay wanted to find cost-effective ways to fix problem culverts when he started his graduate studies. In 2013, Duguay performed the numerical modeling for a baffle conceived by a biologist working for the Government of Newfoundland. That baffle was ultimately slated to repurpose the problem culvert on Craig Creek. A baffle, when slip-lined into an existing culvert, uses a series of symmetrical channels to redirect the flow of water, eliminating previous stressors. Duguay used the proposed geometry of the new baffle and the flow rate of the creek to calculate the variables that can enable or impede fish passage.

A baffle designed to facilitate fish passage. Photo credit MTO

“It looks promising,” Duguay says. “We compared the same model to a fish baffle that’s been recommended by the Department of Fisheries and Oceans (DFO). Our baffle creates bigger recirculation zones where the fish can rest and it’s more calm and it’s deeper. I wouldn’t say the DFO model is worse, but I think we have some advantages with this one.”Duguay likes baffles because they are relatively inexpensive to install; instead of the labour-intensive process of digging up the old culvert, the construction crew can slip the baffle into the existing culvert.

Whether Steelhead can pass through the baffle will require further testing now that the baffle is installed on the creek. If Duguay’s modeling is as accurate as he predicts, Steelhead should be able to swim up the baffle and reach their spawning area. “There’s work being done to address fish passage,” Duguay says. “But I think a part of the problem is with the culture. A lot of engineers finish university and they don’t even know how to make fish passage a priority. So, from my experience, there seems to be a lack of training on the topic.”He says engineering programs should reevaluate how they teach undergrads about habitat protection, ensuring all new engineers have the knowledge and skills necessary to build structures that are safe, stable, and ecologically responsible.

Water cascading through primary and secondary passage of the fish ladder (left) 

and looking downstream at the fish ladder grouted in place and running full (right). Photo credit CSPI and MTO

But in the case of Craig Creek, there’s a complicated problem: the Saugeen First Nation depends on Lake Whitefish, not Steelhead. For centuries, the Ojibway who lived on the Saugeen Peninsula thrived on Lake Whitefish, a species with cultural and spiritual significance to the Nation. Professor Neil Rooney at the University of Guelph conducts research related to environmental assessments in the Traditional Territory of the Saugeen Ojibway Nation. He says Lake Whitefish live and spawn in Lake Huron and are unaffected by the culvert on Craig Creek. Indeed, Craig Creek is used exclusively by Steelhead and therefore only the Steelhead will benefit from improved fish passage. What’s more, he says, the Steelhead that migrate through Craig Creek are an invasive species, introduced to the region by recreational fishers, that feed high on the food chain and create problems for native species. The baffle could, in this case, actually be causing harm to fish habitat in the region. 

Why, then, would the Saugeen First Nation protect fish passage for an invasive species that is destructive to native species like the Lake Whitefish they depend on? Because, Rooney says, the Ministry of Natural Resources in Ontario told them to. “There are lots of discussions between the Ministry of Natural Resources in Ontario and the Saugeen Ojibway Nation around the prioritizing of different species and habitat,” he says. “There’s a tremendous amount of pressure from sports fishers, because sport fishing is a huge industry in Ontario, for the Ministry to maintain the habitat of these Steelhead that are non-native because they’re good fishing fish.”

Freshwater Whitefish. Photo credit

This is part of a larger issue stemming from recent changes to the Fisheries Act. Jeffrey A. Hutchings of Dalhousie University published a paper explaining how changes to the Fisheries Act prioritize protecting only fish habitats that are part of a fishery. He argues that these changes alter the focus of the Fisheries Act, once driven to sustain healthy ecosystems, now driven to serve the needs of industry. Indeed, he specifies the invasive Steelhead as a beneficiary of the new Act due to the fish’s popularity with recreational fishers. He says the scientific literature has well documented the detrimental impact of Steelhead on native species, like the Lake Whitefish so vital to the Saugeen First Nation.

Canada’s First Nations can hunt and fish as part of their constitutional rights. Indeed, many First Nations depend on traditional foods like fish because transporting food to their communities can be expensive, a threat to their food security. First Nations retain some of their independence and connection to their heritage by hunting and fishing. Therefore, the Saugeen First Nation have both a legal and a moral right to a safe and stable habitat for Lake Whitefish. Regardless, in the interests of recreational fishers and to comply with the new Fisheries Act, the Saugeen First Nation was obligated to repurpose the culvert on Craig Creek as directed by the Ontario government.

Even with this legal requirement imposed upon them, the people of the Saugeen First Nation considered repurposing the culvert a low priority. After all, replacing and fixing problem culverts can be labour-intensive and expensive. But if the First Nation failed to provide good fish passage to the Steelhead, they could face a serious fine, potentially millions of dollars.

The baffle modeled by Duguay provided the Saugeen First Nation with a cost-effective way to comply with the Fisheries Act and avoid being fined. But the situation on Craig Creek reflects why good science must be guided by good policy. There are hundreds of problematic culverts throughout North America threatening fish passage, habitat, and spawning areas. The baffle is a valuable solution to this problem, but only if it’s used in an enlightened and responsible way. Using the baffle to protect an invasive and destructive species for the benefit of recreational fishing reflects everything that’s wrong with the current Fisheries Act. As Hutchings says in his paper, the changes to the Act ran contrary to scientific advice and weakened Canada’s ability to “protect, conserve, and sustainably use aquatic biodiversity.” If we can review and revise the Fisheries Act to protect important aquatic ecosystems and First Nation’s fishing rights, we’ll be more likely to use solutions like the baffle where they will provide the best environmental stewardship.

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