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Districts Affected: Yukon River Area
Fall Season Assessment

There have been three pulses of fall chum salmon, two small and one moderate sized, that have entered the Yukon River this season. On an average year, over three quarters of the fall chum salmon and over one half of the coho salmon are in the river by August 31. Fishermen in the lower river have observed salmon holding in sloughs in the delta, which is not typical and may be due to very low water conditions or acclimating to warmer than normal water temperatures before proceeding up river. Normally salmon migrate steadily upstream. During much of August, there was a lack of favorable strong onshore westerly winds associated with carrying salmon into the mouth of the river.

As of August 30, the cumulative fall chum salmon passage was estimated to be a record low of approximately 211,000 fish by the Pilot Station sonar, which is well below the average of 652,000 for this date. The 90% confidence interval around the point estimate suggests the passage could range from 154,000 to 224,000 fall chum salmon. Annual reconstruction of previous runs suggests the point estimate may be conservative and therefore run passage could be towards the upper end of the estimated range. Furthermore, during August and early September, unusually shallow water on the left bank sonar site appeared to be causing salmon to spread out and migrate farther offshore. Fish detection does not appear to be a problem because we have extended the range of the sonar. However, species apportionment is problematic due to very low test fish catches that are used in the estimating model. Some days we do not catch any fall chum salmon. Because most of the few fish caught on the left bank have been coho salmon and whitefish, we may be underestimating fall chum salmon on the left bank. Lower river and Mountain Village test fisheries and subsistence catch reports indicate a higher proportion of coho than fall chum salmon, but the percentage of fall chum salmon in the subsistence catches is higher than indicated in test fishing catches on the left bank at the sonar site. Taking this into account, we assess the fall chum run abundance to be weak with a projected run size of 300,000 to 325,000 fish. We are attempting to test fish below and above the left bank sonar site to increase test fishing catches. Local fishermen have been contracted to conduct drifts with longer gillnets in an effort to determine fish distribution. So far these efforts have not been fruitful, in part, due to the short pulses typical of fall chum salmon and the overall low passage of fish. We are also exploring different sonar sites along the left bank for the future.

The genetic mixed stock analysis data indicates approximately one half of the first small pulse of chum salmon was comprised of summer chum salmon stocks. Samples of the second, moderate sized pulse, suggests that approximately 70% of the second pulse are likely bound for tributaries in the upper Yukon River drainage. Results of genetic sampling are not yet available for the third small pulse. As the run progresses, it is anticipated that an increasing percentage of the fall chum salmon will contribute to the Tanana River stocks which is typical for the later portion of the run. The first pulse of fall chum salmon is expected to be between Circle and Eagle, the second pulse is near Stevens Village, and the third pulse should be near Kaltag.

In contrast, the coho salmon run is above average. The Pilot Station sonar cumulative passage estimate of 141,000 through August 30 is well above the average of 132,000 coho salmon for this date. The Department and cooperating fishermen have been conducting additional test fishing on Flat Island in the southern mouth to supplement assessment project information. The additional catches agree with other assessment projects in that the coho salmon abundance is high relative to fall chum salmon which typically dominate the fall season.

Lower Yukon Cooperative Drift Test Fishery - 6.0” mesh / ADF&G, YDFDA
The Lower Yukon River Test Fish Project concluded on August 28. The cumulative fall chum salmon CPUE for the season was 311.01 which is well below the average of 1,175.98. The cumulative coho salmon CPUE for the season was 265.04 which is below the average of 359.70.

Mountain Village Drift Test Fishery- 5-7/8” mesh / Asacarasarmiut Traditional Council, BSFA
The cumulative CPUE for fall chum salmon is 1,512.56 through August 30 which is below the average of 2,118.34 for this date. The cumulative coho salmon CPUE is 846.77 which is slightly below the average of 953.15 for this date. This project is scheduled to operate through September 10 and should provide evidence of additional fish passage and contributions of fall chum and coho salmon.

Pilot Station Sonar / ADF&G, YDFDA, AVCP/USFWS
The cumulative passage through August 30 is approximately 211,000 fall chum salmon which is below the average of 652,000 for this date. The cumulative passage estimate for coho salmon is 181,000 which is above the average of 132,000 for this date. This project will extend operations to September 7 as it did last year using R&M funding to continue to monitor late fish passage.

Rapids Test Fish Wheel/Stan Zuray
The cumulative count through August 30 is 4,250 chum salmon which is below the historical average of 17,442 fish for this date.

Y-5A Test Fish Wheel/Pat Moore
The cumulative count through August 29 is 651 fall chum salmon which is below the historical average of 1,797 fish for this date. The cumulative count of 13 coho salmon is below the historical average of 120 fish for this date.

Nenana Test Fish Wheel/Kleinschmidt
The cumulative count through August 30 is 863 fall chum salmon which is below the historical average of 894 fish for this date. The cumulative count of 443 coho salmon is above the historical average of 83 fish for this date.

Chandalar River Sonar/USFWS
The cumulative count through August 23 is approximately 6,183 chum salmon which is below the average of 11,569 fish for this date. The project has been terminated unexpectedly early for the season due to crew and safety issues.

Sheenjek River Sonar/ADF&G
The cumulative count through August 30 is approximately 1,500 chum salmon which is below the average of 20,500 fish for this date.

Eagle Sonar/ADF&G and DFO
The project transitioned to counting fall chum salmon as of August 18 with a cumulative count through August 30 of 1,662 fish which is below the average of 3,581 for this date. The preliminary total passage estimate for Chinook salmon through August 17 is 69,650 fish.

Commercial Harvest

The preliminary fall season commercial harvest total for Districts Y-1 and Y-2 through August 5 is 23,063 fall chum, 5,096 coho, and 236 Chinook salmon. Genetic breakdown of the commercial catch suggests that 63% of the catch were lower and middle river summer chum salmon stocks.

Age Composition

Fall Chum Salmon

Lower Yukon Test Fishery:
The fall chum salmon weighted age composition from the 6.0” drift net test fishery through August 28 was 4% age-3, 69% age-4, 24% age-5, and 3% age-6 fish. Sample size was 252 fish. Females were 52%. The age structure this season has been slightly higher than average for age-4 fish, through August 28 typically the average age-4 contributes 66% and age-5 is 31%. However, based on the record high primary parent year escapement in 2005, this year’s age-4 component was expected to be much higher if production was good. The poor production is now suggesting 0.19 return per spawner which is the lowest on record.

Commercial fishery:
The fall chum salmon age composition from the District 1 commercial harvest, periods 1 through 4, was 56% age-4, 40% age-5, and 3% age-6 fish. Sample size was 636 fish. Females were 47%.

Management Strategies

Unfortunately, the fall chum salmon run is poor with a projected run size of 300,000 to 325,000 fish this season and the coho salmon run is judged to be above average in abundance. The Yukon River Drainage Fall Chum Salmon Management Plan specifies a minimum drainage-wide escapement goal of 300,000 fall chum salmon and the likelihood of achieving a run size much greater than 300,000 this late in the season decreases with each passing day.
Therefore, based on the current abundance and in accordance with the management plan, subsistence fishing time is being reduced along the Yukon River in an effort to achieve the drainage-wide escapement goal while continuing to provide opportunity to harvest some fish for subsistence use and take advantage of the abundant coho salmon where they are available in Districts 1-4 and in the Tanana River.

The subsistence harvest of fall chum salmon is expected to be less this year due to many factors including reduced fishing time and lower abundance. Reports of less effort are being attributed to the lateness of the run, expected low catch rates, high costs associated with fishing, lost gear, and lost fishing sites from the spring. The lower expected harvests are a consideration in management actions.

Subsistence fishing time in Districts 1, 2, and 3 was reduced to a schedule of two 24-hour periods per week on August 18 and will return to their 7 day a week schedule beginning Thursday, September 3 to allow opportunity to harvest the abundant coho salmon. District 4 began a reduced schedule of two 32-hour periods a week on August 27. However, subsistence fishing in the Innoko and Koyukuk River drainages will remain open 24 hours a day, 7 days a week due to low fishing effort and inefficient fishing conditions in these drainages. Subdistricts 5A, 5B, and 5C will begin a reduced schedule of two 32 hour periods on September 2. Subdistrict 5D, including the Porcupine River, can expect to begin a reduced weekly fishing schedule of four and one half days later this week. Subsistence salmon fishing in District 6 will likely begin a reduced weekly fishing schedule later this week as well. Additionally, personal use salmon fishing in the Tanana River will close until further notice beginning at 12:00 noon, Wednesday, September 2. Although late pulses have occurred in past years, no additional commercial fishing periods to target coho salmon are anticipated due to the low abundance of fall chum salmon.

Current Management

Commercial periods:
No commercial fishing at this time.

The current subsistence and personal use fishing schedules in the Alaskan portion of the Yukon River are as follows:

Coastal District: open 7 days per week, 24 hours per day, with unrestricted mesh size gillnets.
District Y-1: Subsistence fishing is open from 6 p.m. Thursdays until 6 p.m. Fridays and from 6 p.m. Mondays until 6 p.m. Tuesdays.
Districts Y-2 and Y-3: Subsistence fishing is open from 6 p.m. Sundays until 6 p.m. Mondays and from 6 p.m. Wednesdays until 6 p.m. Thursdays.
District Y-4: Subsistence salmon fishing is open for two 32-hour periods per week from 10 a.m. Sundays until 6 p.m. Mondays and from 10 a.m. Wednesdays until 6 p.m. Thursdays. During open subsistence salmon fishing periods that portion of Subdistrict Y-4A upstream of Stink Creek is open to the use of drift gillnet gear for chum salmon.
Subdistricts Y-5A, Y-5B, & Y-5C: Subsistence salmon fishing will close at 6 p.m. Wednesday, September 2. Subsistence fishing will then be reopen for two 32-hour periods per week from 10 a.m. Fridays until 6 p.m. Saturdays and from 10 a.m. Tuesdays until 6 p.m. Wednesdays.
Subdistrict Y-5D including the Porcupine River: Subsistence fishing is open 7 days per week, 24 hours per day, until further notice.
Subdistricts Y-6A, Y-6B: open for two 42-hour periods each week from Monday 6 p.m. to Wednesday 12 noon and Friday 6 p.m. to Sunday 12 noon, until further notice.
Old Minto Area: open 5 days per week from Fridays 6 p.m. to Wednesdays 6 p.m. until further notice
District Y-6C Personal Use: open for one 42-hour period from 6 p.m. Monday August 31 to 12 noon Wednesday September 2. Beginning at 12 noon on Wednesday September 2, personal use fishing will be closed until further notice.
Innoko River: open 7 days per week, 24 hours per day.
Koyukuk River: open 7 days per week, 24 hours per day.

During the subsistence salmon fishing closures, all gillnets with a mesh size greater than four inches and a length greater than 60 feet must be removed from the water.

Fishermen are encouraged to consult the State of Alaska commercial and subsistence fishing regulations and the federal subsistence fishing regulations before fishing in the Yukon Area.

If you have any questions, please contact the Emmonak ADF&G office at 949-1320. For a 24-hour schedule recording, please call toll-free 1-866-479-7387. Additionally, announcements are available at the following web address: http://www.cf.adfg.state.ak.us/region3/yukhome.php