As the spawning season for late-run Shuswap sockeye runs down, fisheries officials believe the numbers are down compared to the 2014 dominant run, but are not sure by how much.
“Could be 90 per cent (of 2014) or more, it’s hard to know as tagging isn’t finished,” says Pacific Salmon Commission chief biologist Mike Lapointe, who believes salmon are continuing to arrive and tagging will continue into November. “But I think the distribution of spawners will shift, with disproportionately few fish in the Shuswap River.”
Lapointe explains that the Late Shuswap Lake salmon ‘complex’ is comprised of several spawning streams.
The main sockeye spawning sites are Eagle River, Lower and Middle Shuswap rivers, Lower Adams River (where the Salute to the Sockeye was) and Little River, that runs between Shuswap Lake and Little Shuswap Lake.
“Overall, I expect the number of spawners estimated for the entire Late Shuswap complex will be less than the approximately 2.1 million in 2014,” he says. “I think we’ll get about 78 per cent of that.”
While fisheries officials provide weekly updates, preliminary estimates are typically not released until the new year, as a substantial amount of data needs to be processed first.
Lower Adams and Little Shuswap River spawning populations are estimated based on fish tagging, a process that began about two weeks ago and is ongoing, says Lapointe. About 3,000 tags were applied onto the fish last week in the Lower Adams/Little River area, said Lapointe on Friday.
The total number of tags applied as of Thursday, Oct. 24, was almost 9,800 which is estimated to be about 71 per cent of the number of tags applied by about the same date in 2014, says Lapointe.
In 2014, the last dominant run, about 900,000 fish were estimated to have spawned in these two rivers, 700,000 in the Lower Adams and 200,000 in Little River.
“DFO stocks assessment staff are reporting that arrival and spawning will be more spread out than other years,” he says, noting the run began two weeks later than a new normal that was set in 1994. “So it could be that a significant number of tags will be applied in the next week.”
Acoustic estimates at the Lower Shuswap are currently at about 500,000 fish or just over 60 per cent of the more than 830,000 fish that were estimated to have spawned in 2014.
“But daily migration remains strong,” Lapointe said on Friday, Oct. 26.
“The last three daily estimates were about 13,000, 11,000 and 7,000 fish respectively.”
Estimates in the Middle Shuswap River are done visually, which makes interpretation of in-season data difficult, says Lapointe. About 195,000 fish were estimated to have spawned there in 2014.
“I suspect 2018 will be less, perhaps substantially so, but it’s hard to tell at this point; it is a complicated system,” said Lapointe, noting that last year, more late-run sockeye returned to the Shuswap River whereas Adams River is getting a bigger return this year.