|
Salmon forecast: sockeye up, chinook down |
|
December 18, 2016 |
The forecasted return of adult spring and summer
chinook salmon to the Columbia River basin in
2017 will be lower than initial estimates made
last year in December, but the estimate of
sockeye salmon is nearly twice the size of last
year’s estimate, according to an early forecast
of the runs released this week by the U.S. v
Oregon Technical Advisory Committee.
TAC estimated the total run of spring/summer
chinook salmon for 2017 at 160,400 fish. Last
year’s early forecast was 188,800, but the
actual return to Bonneville Dam was higher with
137,215 spring chinook and 119,591 summer
chinook.
A forecast by the Oregon Department of Fish and
Wildlife this week estimates a run of spring
chinook salmon into the Willamette River of
40,200, far lower than last year’s forecast of
70,100 fish, but closer to the actual 2016 tally
of 49,800 spring chinook.
Some 198,500 sockeye will enter the Columbia
River, according to TAC. That is nearly double
last year’s forecast of 101,600 fish, but far
below the actual and surprising count of 342,498
sockeye that passed Bonneville Dam.
The fall chinook forecast is not yet available.
TAC, made up of federal, state and tribal
representatives, was formed by the parties to
the U.S. v. Oregon court case.
According to an interview last year with Stuart
Ellis, harvest management biologist with the
Columbia River Inter-Tribal Fish Commission, the
forecasts are largely age-based and the number
of jack salmon from the current year also aid in
the following year’s forecast.
“We reconstruct the runs based on age data
collected at Bonneville, in the fisheries, and
in escapement areas,” Ellis said in December
2015. “One of the most common methods is to do
statistical regressions between the ages.
Sometimes we use ratios. We look at
relationships between various time periods too.”
TAC also tries to incorporate environmental
information, such as ocean conditions, into its
forecasts, he said.
Jacks have always served as a pretty good index
of the survival of a certain brood to date. In a
way, Ellis said, jacks can be looked at as a
type of ocean indicator. “For spring chinook,
jacks play a big part in our assessment of the
4-year old return which is normally the biggest
age class in any year.”
Of the 160,400 spring/summer chinook forecast
for 2017, 19,300 of the fish are upper Columbia
River spring chinook with 3,700 naturally
produced or wild fish. Some 95,800 (15,200
natural origin) will be destined for the Snake
River and the rest are Mid-Columbia River
stocks. The total upper Columbia River summer
chinook run is anticipated to be 63,100 fish,
according to information from TAC provided this
week by Ellis.
In addition to the Willamette forecast of 40,200
spring chinook, 17,100 fish will head up the
Cowlitz River, 3,100 into the Kalama River and
700 into the Lewis River, all rivers in
Washington State.
Of the 198,500 sockeye, just 1,400 will go to
the Snake River, 54,200 to the Wenatchee River,
137,900 to the Okanagan River, 4,000 to the
Yakima River and 1,000 to the Deschutes River.
This year (2016), the actual count of spring
chinook salmon at Bonneville Dam was 137,215
adult fish and 11,145 jacks, far below the 2015
count of 220,480 adults and 13,314 jacks. The
10-year average is 146,704 adults and 24,884
jacks.
The actual count this year for summer chinook at
Bonneville was 119,591 fish and 10,834 jacks,
also far below the 2015 count of 161,735 adults
and 17,730 jacks. The 10-year average is 95,523
adults and 21,451 jacks.
Again, the actual count for sockeye at
Bonneville in 2016 was 342,498 fish (more than
three times the 2016 early forecast of 101,600
fish). The actual count at Bonneville in 2015
was 510,706 and the 10-year average is 285,072.
The count in 2016 at Lower Granite Dam, the
upper of four lower Snake River dams, was 816
(Lower Monumental was 1,024). The 2015 count at
Lower Granite count was a depressing 440 (one of
the warmest years on record) and the 10-year
average is 983. The count at Lower Monumental in
2015 was 888 and the 10-year average is 983. |
|
Questions or comments about this
article?
Click here to e-mail! |
|
|
|
|
