This story is the third of a multi-part series running throughout June exploring the wide-ranging impacts of persistent drought conditions seen across the province since 2022.
Experts are concerned that low snowpack levels recorded across much of B.C. this year could lead to negative impacts on salmon populations later this summer.
Last year, severe drought conditions and high temperatures caused experts to sound the alarm over potential devastating effects on the province’s salmon populations.
Fish protection orders were issued for some waterways with the goal to maintain water levels for spawning salmon, and in the Kamloops area, an excavator was used to dig a channel that had dried up due to drought to re-establish water flow for migrating fish.
Much of the province, including the B.C. Interior, currently sits between level one and three on the B.C. government’s zero to five drought classification scale, meaning adverse ecosystem impacts are rare, unlikely or possible.
However, Jason Hwang, vice-president of salmon programs the Pacific Salmon Foundation, said drought is especially concerning when looking ahead to this summer.
Hwang said snowpacks are important for driving streamflows, and many B.C. regions have reported low snowpacks.
“Things aren't actually looking terrible locally [in the Thompson-Okanagan], at least at present — but when you take a step back and look at the province as a whole, it's very, very concerning, because these are extraordinarily low snowpacks,” Hwang said.
“As you come into mid summer, late summer, early fall, it's quite likely that these low snowpacks are going to result in extraordinarily low flows even if we don't have a particularly hot summer — because the snowpack is really important to driving your flows.”
Streamflow, water temperature crucial for salmon
Drought can impact salmon populations through its impact on streamflow and water temperature.
Low streamflows can be fatal for salmon, as migration pathways to spawning areas can be blocked. Hwang noted high water temperatures can increase stress on salmon, and can also cause them to die.
Eric Taylor, a UBC professor of zoology specializing in fish conservation, said when there is less water in a waterway, there is less space for fish to move.
“It can restrict access to areas they need to feed and reproduce and migrate,” Taylor said.
He said severe drought creates a lack of water with the potential to create “catastrophic” population loss.
In mid-August 2023, Fortune Creek near Enderby dried up, and Fisheries and Oceans Canada, and First Nations partners attempted to relocate salmon as a last-resort option.
Taylor said this was a last resort because salmon will return to habitat where they’ve historically done well. He says moving them to another place might help them, but it’s not as good as allowing the population to return to its preferred spot.
Another salmon expert, University of British Columbia professor Scott Hinch, predicted the need for similar relocations will grow in the future.
“That's going to become more common,” Hinch said.
“Streams are getting slightly warmer year by year, and with less and less water, these are both the things that we expect to see more of moving forward.”
Changing ecosystems and water temperatures
A big concern for experts is the temperature of waterways and how this will impact the salmon populations. The ideal water temperature varies depending on the species of salmon, but generally, the fish require cooler water.
Hinch said the surface of Interior lakes can be too warm, but the deeper levels don’t have enough oxygen, so salmon stay in a middle strip — which needs to be maintained.
“This is kind of where it’s all happening, these Interior [fish] populations, because the summer stream temperatures get so warm, and the lakes, even though they do have cool sections in them, their ecosystems are changing,” Hinch said.
For now, Okanagan salmon seem to be doing alright, but Hinch said the community must focus on protecting the fish and their habitat.
He says it can be tough to be optimistic about the future of salmon populations, but people need to continue protecting streams to avoid warming.
“We're really in uncharted territory too, because all the baselines are switching,” Hinch said.
“Every year is a new record, a new warmer temperature, or drier or less water as we move forward.”
Hinch explains that riparian areas, the strip of land growing alongside bodies of water where vegetation grows, also plays an important part of keeping water the right temperature for salmon.
He said in many Interior areas, riparian areas have been cleared for agriculture or other land use activities.
“Salvage logging or things like that that remove the trees has a big impact on the stream temperatures. So whatever we can do to protect the streams and keep the temperatures from not increasing any further is going to be really important.” Hinch said.
Hwang said he saw the impact of riparian areas in Kamloops’ Noble Creek area last summer.
One section of the creek with little to no shade-creating vegetation due to unnatural development resulted in salmon dying. However, another section 50 metres away had a riparian area with thick vegetation creating shade — and this area was full of fish.
Cumulative impacts of multi-year droughts
When asked if multi-year droughts have a cumulative impact on salmon populations, Hwang said it’s quite likely there’s compounding effects from multiple drought years in a row.
“The flow specialists, the river morphologists and the water managers tell us that when you have multiple years in a row, things like recharge of groundwater or aquifers does not happen like it normally would,” Hwang said.
In some cases, groundwater is critical for maintaining base flows in streams in the late summer. When there hasn’t been rain for a long time, water has been stored in the ground and gradually releases into streams.
Hwang said groundwater is especially important because it is cold. When looking at a stream in late summer, salmon are often hiding out in places where groundwater is flowing into the creek.
“When you have multiple years of drought in a row, and you have reduced recharge of your groundwater, you're actually losing flow that would be really important to the stream in the late summer, when you have drought conditions,” said Hwang. “You're also losing a cold water input that might be providing local refuge areas when the broader conditions are not hospitable for salmon.”
Hwang said more research could be done specifically for the Interior, but experts understand this is happening broadly around the province.
Taylor pointed to the impacts cumulative droughts could have on juvenile salmon, saying species where juveniles stay in the stream for a year or two before heading to oceans are particularly at risk of low flow, warm pools, and increased stressors.
He likened a recurring drought to being punched in the face multiple times versus once.
“Even if the so-called punch in the face is the same intensity, obviously, if you get it four times in a row it's a lot worse than just getting it once,” Taylor said.
A loss of salmon populations will ripple up through our ecosystem, because there’s less salmon for people, First Nations, grizzly bears, killer whales — the entire ecosystem.
All three experts said the level of concern over Okanagan salmon amid drought conditions greatly depends on the species.
Hwang said the Okanagan Nation Alliance has been working hard to rebuild Okanagan sockeye populations, meaning these fish have been doing quite well.
The large sockeye population means it is buffered slightly when feeling the effects of drought.
Taylor said the more fish trying to come back to spawning grounds, the higher the likelihood some will make it through increasingly poor stream conditions.
Changes required to province’s current approach
Hwang said to best protect fish populations, changes need to be made to the province's current approach.
“The current management system is based on a time when we didn't have drought as severe or as frequently, and the management system now, it tends to wait until there's an extreme problem,” he said.
“The ministry doesn't really have many tools at their disposal, they can kind of regulate water use, but that comes, usually, at some significant trade-off or consequence to the entity that would like to be using that water.”
Hwang said current water restrictions aim to protect the minimum flow — or the minimum amount of water needed for salmon to survive at that time. He said while this is an important thing to consider, it's not all that's needed for fish to survive and be healthy.
Hwang and Hinch agree an approach to water resources, salmon and fish habitat needs to come from a variety of players, including the province, salmon experts and water experts.
“We have a responsibility to look after these things for the future generations, for all of the ecosystem needs that depend on salmon — and it's within our control," Hwang said.
"We can do a better job of this, but the system that we have in place right now wasn't set up to deal with present-day conditions, and we can't just kind of sit there and keep hoping it gets better.
“We have some healthy salmon populations, but we have a lot of them that are not doing well, around half are at some level of conservation concern."
Hinch said people need to shift towards a proactive approach. He noted while climate change was discussed about 20 years ago, systems didn’t necessarily manage for that.
“I don't think any of us fully appreciated how quickly things would change, nor the scale of what was about to happen, because the scale is what's monumental,” said Hinch.
“This is not just a couple of streams — you're talking about all of them. They all have the potential to get quite warm and dry, and it's only with effective management of the landscape can you ensure that streams maintain enough water and of the right temperature so that fish can rear in them as juveniles and spawn in them as adults.”
