Columbia salmon managers may extend the lower river’s spring Chinook season for another seven days.
That after the ongoing eight-day extension on through tomorrow was expected to yield only 1,362 kings, including 767 of the upriver fish.
That brings the catch tally for above-Bonneville-bound springers since February to 4,587, nearly 3,000 below the guideline managers are using.
If approved in its current form, the season would be extended from Saturday, April 16, through Friday, April 22.
Managers are puzzled by what the river is telling them. A fact sheet out early this afternoon says:
Bonneville Dam passage of Chinook through April 13 totals 864 adults. Based on the recent 5-year average, which includes four late-timed years, passage is typically about 2% (range 0.1% to 4%) complete on April 13. The 10-year average completion percentage is 8% (range 0.1% to 32%).
The 5-year average 50% passage date is May 8; therefore it is difficult to make accurate conclusions regarding run size at this time.
Indicators for the upriver run strength are mixed; negative indicators include the low cumulative Bonneville Dam count and low catch rates in the lower river sport fishery to date. Positive indicators include a high proportion of upriver fish in non-Indian catch since early February and the improved catch rate from test fishing and ongoing research activities.
Then there’s the Columbia’s water conditions:
During April 1-12, discharge at Bonneville Dam averaged 338 kcfs, including about 111 kcfs in spill. The discharge peaked at 390 kcfs on April 5 and dropped to 303 kcfs by April 13. The 5-year average discharge for April 14 is 217 kcfs. River stage is currently at 10.0 feet with a predicted rise to 11.4 feet by April 18.
Bonneville Dam discharge is predicted to average 266 kcfs from April 16-22 and 274 kcfs from April 23-30. Water visibility is 2.0 feet compared to 4.0 feet on April 1. The 5-year average visibility for this date is 4.7 feet.
Water temperature was 47° F on April 12. Spring water temperatures have been colder than both the 5- and 10-year averages.