In their latest research, Dr Lia Chalifour and colleagues evaluate the potential benefits of 14 management strategies – spanning fisheries, habitat, pollution, pathogens, hatcheries and predation management dimensions – on 19 genetically and ecologically distinct populations of the five Pacific salmon species in the lower Fraser River, British Columbia, Canada.

Fisheries closures in British Columbia have become the norm, with ‘good years’ for returning stocks becoming increasingly rare and geographically isolated. Meanwhile, fisheries regulations have become more proactive, fisheries scientists are working to incorporate more data than ever to predict returns, and Indigenous communities are taking leadership roles in limiting harvest opportunities voluntarily when returns are poor. Yet the bad years keep coming.

The Fraser is the largest salmon-bearing river in British Columbia, supporting 54 unique populations, known as Conservation Units (CUs), of wild Pacific salmon – 19 of which breed in the lower Fraser River. Our new open-access study shows that all 19 of these CUs are on a declining trajectory over the next 25 years. Crucially, we also found that it’s not too late to improve their outlook if we invest strategically in their recovery.

We observed that without interventions, none of the 19 CUs examined in this study are likely to be assessed as “green status”, or healthy and able to sustain fisheries under Canada’s Wild Salmon Policy, in the next 25 years. This is despite three CUs being classed as green status at the time of the study, which tells us that things are only going to get worse for these salmon unless we pivot away from business as usual and make salmon restoration a priority.

For the lower Fraser, which has a legacy of converting salmon habitat into highways and urban and industrial developments, the most effective solution is an overhaul in habitat management. By implementing a combined habitat strategy that includes barrier removal, estuarine and freshwater restoration, improved policies for watershed management, and protection of remaining habitat, 14 of the 19 CUs are likely to achieve green status at a cost of $20 million per year for 25 years, or the annual equivalent of $4.25 per person in British Columbia.

Doubling this investment and implementing all 11 identified management strategies, along with a new co-governance framework between Indigenous and Crown governments to cooperatively manage salmon, could lead to the recovery of up to 17 CUs.

To discover the most cost-effective management strategies to recover salmon in the lower Fraser, our team – led by Dr. Tara Martin at UBC – reached out to over 100 salmon experts in the lower Fraser region, and brought almost 50 of them together in-person (pre-COVID) over three days to do a deep dive into this problem. Working together with Indigenous fisheries and lands managers, commercial fisherman, DFO stock assessment scientists, salmon scientists and managers, we developed management strategies and estimated their benefit to salmon recovery, their cost, and their socio-political feasibility.

To me, the experience of bringing together these groups for a common purpose was one of the most powerful parts of this project. The fact that we were able to come up with a clear roadmap for the future of these salmon populations together speaks to a shared commitment to salmon and the ability of decision science frameworks like Priority Threat Management (PTM) to help find solutions to complex conservation problems.

Priority Threat Management is a conservation decision science framework developed by Tara and her colleagues that considers the predicted benefit, cost, and feasibility of management strategies to rapidly identify which strategies will have the greatest impact on the largest number of populations. PTM is particularly effective because it brings together all relevant parties – in our case managers, scientists, fishers, local and Indigenous knowledge holders, and conservationists – to find these solutions together. It also uses these many facets of knowledge to make predictions about the actual benefit of implementing a management solution – the closest we can get to achieving 20/20 vision into the future.

Taking an integrated approach can highlight key pieces of data and potential solutions that could easily be missed. For example, a stock assessment biologist together with a commercial fisherman can say with high confidence how a change in fisheries management will play out for salmon populations. A land manager and restoration biologist can tell you which sloughs salmon are dying in due to anoxic conditions and what it would take to restore that habitat. This is all crucial information to piecing together the big picture for salmon. PTM then helps us to quantitatively assess which pieces are likely to give us the biggest bang for our conservation buck.

The next step is for decision-makers, managers, conservationists, and the public to support these results and make a detailed implementation plan for the priority strategies. Our work shows that applying a co-governance framework for salmon management between Indigenous and Crown governments improves the outlook for salmon by increasing the success and likelihood of implementation of management strategies.

This aligns with the trajectory that British Columbia and Canada are on, working towards reconciliation with Indigenous communities and recognizing that existing colonial frameworks for managing lands and resources are not working and often in direct violation of Indigenous rights and title as defined by UNDRIP, DRIPA, and the Canadian constitution. While the path to reconciliation is even more complex than the path to salmon recovery, parts of these journeys can be walked together. Our research suggests that making an effort toward co-governance in the lower Fraser region will have significant benefits for salmon.

If we can commit to changing the way that we manage salmon and their habitats in the lower Fraser River, and implement these priority strategies in a timely manner, then in 25-years time “good years” should become the norm for wild salmon returns in this region. We have the answers. Now the question is: will we act on them in time?

For more information about our research and the Martin Conservation Decisions Lab, visit: https://www.taramartin.org/research/lower-fraser-river-salmon/

Read the full paper Identifying a pathway towards recovery for depleted wild Pacific salmon populations in a large watershed under multiple stressors in Journal of Applied Ecology