A new study published this week provides strong evidence that Skeena River chum salmon were in the past up to 52 times more abundant than at present.
The study reported that on average each year from 1916 to 1919, between 268,000 and 471,000 chum salmon returned to the Skeena. That compares to fewer than 9,000 chum salmon that have returned each year since 2007.
Researchers with SkeenaWild Conservation Trust, Wild Fish Conservancy, and The University of Montana’s Flathead Lake Biological Station wrote the article, entitled Abundance of Skeena River chum salmon during the early rise in commercial fishing.
It appeared in the journal Transactions of the American Fisheries Society. The research applied a Bayesian analysis to catch data derived from historical salmon cannery records.
Not only is the current abundance of Skeena chum salmon very low, the enormity of their decline over time is much greater than previously thought.
“Our analysis enables us to look further back in time and more accurately assess the severity of loss in the Skeena,” said SkeenaWild executive director Greg Knox. “Previous estimates of historical salmon abundance have suffered from a ‘shifting baseline syndrome,’ whereby evaluations have been based on data from the 1950s at best, and often the 1980s.”
“Intense harvest pressure over the last century is likely the single largest factor contributing to the sustained decline in Skeena River chum,” said the report’s lead author, Michael Price. “However, other interactive influences such as reduced ocean productivity, habitat degradation, competitive interactions with hatchery fish, and bycatch in mixed-stock fisheries, may now inhibit the recovery of Skeena chum.”
Although chum salmon are not currently an economically important species for Northern B.C. commercial fisheries, they deliver vital marine nutrients to coastal and terrestrial systems.
“It is plausible that the fertility of the Skeena River and its estuary has declined considerably as a result of more than 100 years of intense exploitation of most Skeena salmon species, and the subsequent reduction in returning salmon nutrients,” said coauthor Nick Gayeski.
According to the study’s authors it may be possible to once again see substantially larger wild chum populations, but only if conservation measures are immediately initiated.
“The Skeena is still a relatively intact ecosystem with great habitat. If the right measures were put in place, we could see it become the great chum river our research shows it once was,” said co-author Jack Stanford.Price, M.H.H.1, Gayeski, N.2, and Stanford, J.A.3
Abundance of Skeena River chum salmon Oncorhynchus keta, during the early rise in commercial fishing.
Transactions of the American Fisheries Society. DOI: 10.1080/00028487.2013.790842
1 SkeenaWild Conservation Trust, Smithers, BC, Canada
2 Wild Fish Conservancy Northwest, Duvall, WA, USA
3 Flathead Lake Biological Station, The University of Montana, Polson, MT, USA
To view the study, visit:www.skeenawild.orghttp://www.tandfonline.com/eprint/xfVKcKCsBPVMXV2t4WQn/full
For more information contact:
Greg Knox - SkeenaWild Conservation Trust (www.skeenawild.org
Michael Price - SkeenaWild Conservation Trust (www.skeenawild.org
Nick Gayeski – Wild Fish Conservancy (www.wildfishconservancy.org
Jack Stanford - The University of Montana (www2.umt.edu/flbs/,