|April 08, 2020|
The deadly gauntlet Fraser salmon must Travel to come home
|The rockslide at Big Bar just north of Lillooet was a natural disaster that blocked the Fraser last summer, making it impossible for many returning salmon to return to their natal spawning streams. Of the five million sockeye expected to return for example, only about 300,000 made it to their spawning grounds.|
The Tyee has now learned that natural fish passage on the Fraser River will not be restored in time for the 2020 salmon migration.
The only upside of the disaster is that it's shining a new light on what we call the Gauntlet: the tortuous path that all six species of Pacific salmon must run every year as they return from their migrations on the high seas to fresh water streams across the 21 million-hectare Fraser River watershed.
The rockslide was an act of nature that with engineering expertise and brute force can eventually be fixed. But as the Gauntlet illustrates, what will prove much harder is to save Fraser salmon from the trajectory of decline they were already on before the rockslide happened.
What follows is a visual representation of the heroic journey that Fraser salmon make against all odds. Think of the Gauntlet as an unyielding attack from all angles. An ordeal. It's what Fraser River salmon must face every year, and it will become only more deadly unless we can do more to prioritize their existence.
1. High seas marine survival
Fraser salmon spend multiple years feeding in and around the Gulf of Alaska before returning home. Survival on the high seas has been getting worse. No one really knows why, although it's thought food has become scarce and less nutritious. Wild fish have to compete with huge numbers of human-produced hatchery fish for food out there, and warming oceans have been implicated in marine food scarcity, as well as the northward migration of novel predators.
2. Marine commercial and sports fishing in marine waters
As the fish approach the Pacific coast, industrial fishing fleets intercept home-bound salmon, as do sports fishermen and Indigenous fishers. Fraser-bound salmon are chased from southeast Alaska to Haida Gwaii, along the west coast of Vancouver Island, through the Johnstone and Georgia straits, and across the Salish Sea.
3. Fish farms in BC coastal waters
Fraser-bound fish pass by salmon farms on the inside and outside of Vancouver Island, including in the Broughton archipelago and Discovery Islands region. The farms are like small cities of densely-packed farmed salmon --- a source of pollution, disease and unnatural levels of parasites.
4. Danger on the lower Fraser River: pollution and more fishing
As they approach the Fraser, the salmon enter a giant plume containing the outfall of dozens of sewage treatment plants and untold industrial and city-suburban pollution discharges.
Depending on the year, sports fishermen get openings for angling, as do fishers using gillnets, which are highly effective but non-selective in what they catch.
The floodplain coast and islands across the Heart of the Fraser (between Mission and Hope, B.C.) have been channelized and razed of trees for farming and other development. Intensive farming in the Fraser Valley pollutes the river while flood works have cut off sloughs and side channels which were once salmon nurseries and refugia.
5. Through the canyon into the empire of the beetle
Fish must then navigate up the 375 kilometre-long Fraser Canyon between Lytton and Yale --- rising more than 900 metres in elevation, the river is squeezed into a narrow chasm.
Along the way, the impacts of forestry and the widespread destruction of forests from the mountain pine beetle have silted up rivers, changed hydrology and further degraded the river habitat. Siltation and other logging impacts are worse in the smaller feeder systems and spawning areas that are critical to spawning success.
6. Warming river water temperatures
Climate change affects the entire journey, but as salmon approach their natal streams, they must withstand increasingly warming water temperatures: when it gets over 20 C, their strength is sapped --- making fish susceptible to opportunistic infections and disease.
7. The ongoing rockslide disaster at Big Bar
In 2019, the salmon that survived The Gauntlet nosed up to a new immoveable mass of rock just north of Lillooet, just as they were almost home. Despite efforts to remove and blast rock this year, natural fish passage will not be restored in time for the 2020 salmon migration. Some experts fear the ongoing blockage could wipe out already endangered populations of salmon, including the Stuart Lake sockeye.