Salmon in a changing world

November 24, 2023

By: Dene Moore

Wildfires and floods, drought and disaster. The signs of a warming planet are everywhere.

Climate change is putting ever more stress on salmon runs already burdened by open net-pen salmon farms, overfishing, loss of habitat, industrial activity and development.

Global warming is challenging salmon throughout their lifecycle, from stream to ocean and back again, Dr. Jonathan Moore, head of Simon Fraser University’s Salmon Watersheds Lab, told more than 230 attendees this week during Watershed Watch’s webinar “Science and Stewardship of Salmon Watersheds in an Era of Climate Change.

Events like an atmospheric river cause increased flooding and scouring, which can dislodge salmon eggs buried in the gravel. Water flow is shifting in many rivers, with less and warmer water during summer.

Dr. Jonathan Moore

“As the system gets changed, salmon are having to cope with that impact,” said Dr. Moore, a professor of biological science and resource and environmental management at SFU, where he holds the Liber Ero Chair of Coastal Science and Management.

In some river systems, they’re starting to die.

Changing food web

The life cycle of salmon is timed to the life cycle of other species upon which they rely for survival. As these ecosystems change, the timing of the food web is changing, Dr. Moore explained.

For example, if young salmon migrate to the ocean when the food web is right, they survive. If their timing is off, they are more likely to die.

There is good news.

The lab compiled data on when salmon along the North Pacific coast are migrating to the ocean and found that salmon are adapting, migrating earlier or later in response to the changing climate.

The life cycles of those ocean species are also changing, though. The question is whether they are changing more rapidly than the salmon that rely on them.

The return to freshwater to spawn is another key part of the salmon life cycle.

Another study by the lab gathered spawning data from California to Alaska and found a wide range of spawning, from June and July to November and even February. Salmon have already started to adapt to warming water temperatures in summer, Dr. Moore said.

In B.C., we can expect to see the time of salmon life cycles shift in the coming decades.

“They’ve coped with amazing challenges over their evolutionary lifetime and they’ve found solutions,” he said.

Not just global warming

These challenges are coupled with other stressors, from mining and forestry to overfishing and the dangers of open net-pen salmon farming.

Rising sea levels, coupled with coastal development are putting a coastal squeeze on habitat.

Flood control infrastructure in areas like the Lower Fraser region have cut off habitat. Work like Connected Waters – Watershed Watch’s campaign to reconnect 1,500 kilometres of salmon habitat blocked by outdated flood infrastructure in the Lower Fraser floodplain – is helping.

There are agricultural and forestry pressures, land use and water use decisions, all of which have immediate and direct impact on salmon habitat and salmon survivability.

Overfishing, like the devastating interception fisheries in southeast Alaska, continue and there is a growing body of scientific evidence of the harmful effects of open net-pen salmon farms on wild salmon populations.

“It’s just one more hammer on salmon populations,” Dr. Moore said. But “there is some exciting action happening in terms of getting some of these salmon farms out of some of those key migration pathways.”

While glacial melting is affecting salmon habitat it is also creating new habitat, particularly in northwestern B.C., where new stream beds appear as the glaciers recede. The problem is that these newly exposed stream beds create new mining opportunities, which can have a detrimental effect.

Policy changes

Dr. Moore worries wild salmon are suffering a death by a thousand cuts. He would like B.C. to have legislation that considers cumulative effects, rather than looking at individual impacts in isolation.

“Salmon are resilient. They’ve adapted to a lot over their lifecycle, and they do have the capacity to cope with change,” he said. “There’s a lot we can do.”

Share This Story!

Salmon in a changing world

November 24, 2023

By: Dene Moore

Wildfires and floods, drought and disaster. The signs of a warming planet are everywhere.

Climate change is putting ever more stress on salmon runs already burdened by open net-pen salmon farms, overfishing, loss of habitat, industrial activity and development.

Global warming is challenging salmon throughout their lifecycle, from stream to ocean and back again, Dr. Jonathan Moore, head of Simon Fraser University’s Salmon Watersheds Lab, told more than 230 attendees this week during Watershed Watch’s webinar “Science and Stewardship of Salmon Watersheds in an Era of Climate Change.

Events like an atmospheric river cause increased flooding and scouring, which can dislodge salmon eggs buried in the gravel. Water flow is shifting in many rivers, with less and warmer water during summer.

Dr. Jonathan Moore

“As the system gets changed, salmon are having to cope with that impact,” said Dr. Moore, a professor of biological science and resource and environmental management at SFU, where he holds the Liber Ero Chair of Coastal Science and Management.

In some river systems, they’re starting to die.

Changing food web

The life cycle of salmon is timed to the life cycle of other species upon which they rely for survival. As these ecosystems change, the timing of the food web is changing, Dr. Moore explained.

For example, if young salmon migrate to the ocean when the food web is right, they survive. If their timing is off, they are more likely to die.

There is good news.

The lab compiled data on when salmon along the North Pacific coast are migrating to the ocean and found that salmon are adapting, migrating earlier or later in response to the changing climate.

The life cycles of those ocean species are also changing, though. The question is whether they are changing more rapidly than the salmon that rely on them.

The return to freshwater to spawn is another key part of the salmon life cycle.

Another study by the lab gathered spawning data from California to Alaska and found a wide range of spawning, from June and July to November and even February. Salmon have already started to adapt to warming water temperatures in summer, Dr. Moore said.

In B.C., we can expect to see the time of salmon life cycles shift in the coming decades.

“They’ve coped with amazing challenges over their evolutionary lifetime and they’ve found solutions,” he said.

Not just global warming

These challenges are coupled with other stressors, from mining and forestry to overfishing and the dangers of open net-pen salmon farming.

Rising sea levels, coupled with coastal development are putting a coastal squeeze on habitat.

Flood control infrastructure in areas like the Lower Fraser region have cut off habitat. Work like Connected Waters – Watershed Watch’s campaign to reconnect 1,500 kilometres of salmon habitat blocked by outdated flood infrastructure in the Lower Fraser floodplain – is helping.

There are agricultural and forestry pressures, land use and water use decisions, all of which have immediate and direct impact on salmon habitat and salmon survivability.

Overfishing, like the devastating interception fisheries in southeast Alaska, continue and there is a growing body of scientific evidence of the harmful effects of open net-pen salmon farms on wild salmon populations.

“It’s just one more hammer on salmon populations,” Dr. Moore said. But “there is some exciting action happening in terms of getting some of these salmon farms out of some of those key migration pathways.”

While glacial melting is affecting salmon habitat it is also creating new habitat, particularly in northwestern B.C., where new stream beds appear as the glaciers recede. The problem is that these newly exposed stream beds create new mining opportunities, which can have a detrimental effect.

Policy changes

Dr. Moore worries wild salmon are suffering a death by a thousand cuts. He would like B.C. to have legislation that considers cumulative effects, rather than looking at individual impacts in isolation.

“Salmon are resilient. They’ve adapted to a lot over their lifecycle, and they do have the capacity to cope with change,” he said. “There’s a lot we can do.”

Share This Story!

Stand with us to defend wild Pacific salmon

Stand with us to defend wild Pacific salmon

One Comment

  1. WANDA J CULP December 1, 2023 at 9:40 am - Reply

    Coastal and River-bound indigenous Alaska Natives are keen to the world of salmon society hardships produced by global warming, this article describes those conditions well. Overfishing, loss of habitat, open net salmon farms are all tied to commercialization through raging exploitation. These commodifying of nature’s resources creates hardships for all living systems. Atmospheric rivers of heavy rain accompanied with high intense winds create floods, landslides, melting freshwater glaciers emitting tons of silt into saltwater habitat – added to droughts and wildfires are literally killing us! FOOD 1st must become the lawmaker’s priority to managing land, water, and clean air. Big industry can pitch in cleaning up after themselves or eat their money when all else is gone.

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