Kuskokwim River Harvest Estimates

Harvest Estimates: 7/5/2018 Subsistence Opportunity
Tuntutuliak - Akiak
Prepared by USFWS

This document presents harvest and effort estimates as well as fisher-trip information for the subsistence salmon fishery
opportunity on the Kuskokwim River that occurred on July 5, 2018 within the Yukon Delta National Wildlife Refuge (YDNWR)
boundaries. The production of these estimates was a highly collaborative effort between the U.S. Fish and Wildlife Service
(USFWS), the Orutsararmuit Traditional Native Council (OTNC), the Alaska Department of Fish and Game (ADF&G) and
the Kuskokwim River Inter-Tribal Fish Commission (KRITFC) in cooperation with the Bering Sea Fisherman’s Association
(BSFA). These estimates encompass harvest taken in the portion of the main-stem Kuskokwim River between
and including the villages of Tuntutuliak and Akiak. Harvest and effort estimation was conducted by USFWS staff
using the same methods as in 2016 and 2017. Please contact Ben Staton (benjamin_staton@fws.gov) if you have any questions
regarding these estimates.

Opportunity Details
The YDNWR federal in-season manager, with authority delegated by the Federal Subsistence Board and in consultation with
the KRITFC, announced a subsistence fishing opportunity for Chinook salmon within the YDNWR waters for federallyqualified subsistence users. The opportunity was 12 hours in duration, starting at 9:00AM July 5 and ending at 9:00PM July
5. The special action can be found here, and the corresponding news release here.

Data Sources
• 94 fisher interviews were used in this analysis.
– 29 fisher interviews collected by OTNC from the Bethel boat harbor were used.
– 20 fisher interviews collected by OTNC from Bethel area fish camps were used.
– 43 fisher interviews collected by KRITFC/BSFA community-based monitoring efforts were used.
– 2 fisher interviews collected monitors trained by ADF&G Division of Subsistence staff stationed in Kasigluk were
used.
• 81 interviews were from drift boat fishers.
• 13 interviews were from set net fishers.
• USFWS flew 2 aerial surveys to count drift boats and set nets (3 were scheduled but the morning flight was canceled
due to inclement weather).

Effort Estimates
• 276 drift boat trips were estimated to have occurred during the opportunity.
• During aerial survey flights between Tuntutuliak and Akiak, we observed:
– 87 drift boats between 2:00PM and 4:00PM,
– 90 drift boats between 6:40PM and 8:00PM, and
• Of the drift boats counted on the second flight, an estimated 30% were also counted during the first flight.
• 126 drift boat trips were estimated to have began and ended during times that were not flown.
• We observed 13 set nets fishing in the main-stem Kuskokwim River during the opportunity.

Harvest Estimates
• An estimated total of 24,800 (21,210 - 28,680) salmon were harvested.
– An estimated total of 1,020 (820 - 1,240) Chinook salmon were harvested.
– An estimated total of 12,500 (10,380 - 14,760) chum salmon were harvested.
– An estimated total of 11,280 (9,250 - 13,490) sockeye salmon were harvested.
• Harvest by set nets accounted for an estimated 1,220 (830 - 1,670) total salmon (4% Chinook salmon, 35% chum
salmon, and 61% sockeye salmon).

1

Table 1. Breakdown of relevant quantities by river stratum (area). It was necessary to pool data from the Johnson-Napaskiak
stratum in with the Tunt-Johnson to produce the estimate for the Tunt-Johnson stratum.

Stratum

Interviews

Max Drift
Count

Est. Drift
Trips

Chinook
Harvest

Chum
Harvest

Sockeye
Harvest

4
20
52
18
94

20
22
47
12
101

50
61
132
33
276

230
300
370
120
1,020

3,670
4,330
3,340
1,160
12,500

2,540
3,250
4,800
690
11,280

Tunt-Johnson
Johnson-Napaskiak
Napaskiak-Akiachak
Akiachak-Akiak
Total

Table 2. Specific quantities for the decision framework used by the USFWS and KRITFC. Salmon/boat is total salmon
harvest per drift boat and Ratio is the chum/sockeye:Chinook salmon ratio. Quantities were calculated using the harvest
estimates for each species and the number of estimated number of boat trips, not the raw interview values.
Area

Quantity

Below Johnson R.
Above Johnson R.
Below Johnson R.
Above Johnson R.

Salmon/Boat
Salmon/Boat
Ratio
Ratio

Mean

Lower 95%

Upper 95%

129
76
27.3
22.6

93
62
18.1
17.1

168
91
40.9
29.9

Figure 1. Distribution of relevant quantities from all collected drift boat interviews, excluding those conducted by USFWS
law enforcement officers. BBH = Bethel boat harbor, CBM = community-based monitoring, FC = Bethel area fish camps.

Total Salmon Catch/Trip
25
All Mean = 42.06
BBH Mean = 34.36
CBM Mean = 45.08
FC Mean = 43.88

20

Frequency

Chinook Salmon Catch/Trip

Chum/Sockeye Salmon Catch/Trip

25
All Mean = 1.98
BBH Mean = 1.68
CBM Mean = 2.47
FC Mean = 1.35

20

20

15

15

15

10

10

10

5

5

5

0

0

0

20

40

60

80

100

0

1

Trip Duration (Hours)

20

2

3

4

5

6

7

20

Soak Hours/Trip

All Mean = 2.91
BBH Mean = 3.4
CBM Mean = 2.39
FC Mean = 2.88

25

All Mean = 40.09
BBH Mean = 32.68
CBM Mean = 42.61
FC Mean = 42.53

30
25

15

60

80

100

Species Ratio

All Mean = 1.56
BBH Mean = 1.01
CBM Mean = 1.8
FC Mean = 1.63

35

40

All Mean = 22.87
BBH Mean = 19.29
CBM Mean = 21.93
FC Mean = 29.74

30
25
20

20
15
15

10

10

10
5

0
2

4

6

8

5

5

0

0
1

2

3

2

4

5

6

20

40

60

80

100

Appendix A: Bethel Boat Harbor Interview Information Detailed Summaries
Information is for drift nets only
Column Meanings
•
•
•
•
•
•
•

Area: The area of the river the trip occurred in
N: The number of interviews with fishing reported in each area
Min: the minimum value among all interviews conducted in each area
25%: the value that 25% of the interview values fell below in each area
Mean: the mean value among all interviews conducted in each area
75%: the value that 75% of the interview values fell below in each area
Max: the maximum value among all interviews conducted in each area

Table A1. Summary of catch rates for Chinook salmon by area (units are catch per 150 feet of net soaked for 1 hour).
Area

N

Min

25%

Mean

75%

Max

Tunt. - Johnson R.
Johnson R. - Napaskiak
Napaskiak - Akiachak
All

1
2
22
25

0
1
0
0

0
1.1
0.1
0

0
1.2
2.7
2.5

0
1.4
2.9
2.5

0
1.5
15
15

Table A2. Summary of catch per trip for Chinook salmon by area.
Area

N

Min

25%

Mean

75%

Max

Tunt. - Johnson R.
Johnson R. - Napaskiak
Napaskiak - Akiachak
All

1
2
22
25

0
1
0
0

0
1
0
0

0
2
2
2

0
2
2
2

0
2
5
5

Table A3. Summary of catch rates for chum/sockeye salmon by area (units are catch per 150 feet of net soaked for 1 hour).
Area

N

Min

25%

Mean

75%

Max

Tunt. - Johnson R.
Johnson R. - Napaskiak
Napaskiak - Akiachak
All

1
2
22
25

54
40
9
9

54
41.6
15.4
18

54
43.2
43.6
44

54
44.9
64.5
60

54
46.5
144
144

Table A4. Summary of catch per trip for chum/sockeye salmon by area.
Area

N

Min

25%

Mean

75%

Max

Tunt. - Johnson R.
Johnson R. - Napaskiak
Napaskiak - Akiachak
All

1
2
22
25

54
31
9
9

54
43
14
15

54
56
30
33

54
68
30
49

54
80
108
108

Table A5. Summary of the percent of salmon catches that were Chinook salmon by area.
Area

N

Min

25%

Mean

75%

Max

Tunt. - Johnson R.
Johnson R. - Napaskiak
Napaskiak - Akiachak
All

1
2
22
25

2%
0%
0%

3%
0%
0%

0%
3%
7%
6%

3%
8%
8%

3%
27%
27%

3

Table A6. Summary of trip start time by area.
Area
Tunt. - Johnson R.
Johnson R. - Napaskiak
Napaskiak - Akiachak
All

Min

25%

Mean

75%

Max

11:00AM
2:00PM
8:30AM
8:30AM

11:00AM
2:15PM
9:30AM
9:30AM

11:00AM
2:30PM
12:09PM
12:18PM

11:00AM
2:45PM
1:45PM
2:00PM

11:00AM
3:00PM
7:45PM
7:45PM

Table A7. Summary of trip end time by area.
Area
Tunt. - Johnson R.
Johnson R. - Napaskiak
Napaskiak - Akiachak
All

Min

25%

Mean

75%

Max

3:33PM
6:40PM
10:00AM
10:00AM

3:33PM
7:02PM
1:58PM
2:06PM

3:33PM
7:24PM
3:22PM
3:41PM

3:33PM
7:45PM
5:09PM
5:14PM

3:33PM
8:07PM
9:00PM
9:00PM

4

Appendix B: Village-Specific Interview Information Detailed Summaries
Information is for drift nets only; data from Kasigluk, Kwethluk, and Akiachak are not shown becasue very few interviews were
available there.
Column Meanings
•
•
•
•
•
•
•

Village: The village the interview occurred in
N: The number of interviews conducted in each village
Min: the minimum value among all interviews conducted in each village
25%: the value that 25% of the interview values fell below in each village
Mean: the mean value among all interviews conducted in each village
75%: the value that 75% of the interview values fell below in each village
Max: the maximum value among all interviews conducted in each village

Table B1. Summary of catch rates for Chinook salmon by village (units are catch per 150 feet of net soaked for 1 hour).
Village

N

Min

25%

Mean

75%

Max

Akiak
Napaskiak
All

13
19
32

0
0
0

0
0.7
0.4

2.6
2.1
2.3

3
3.7
3.5

12
6
12

Table B2. Summary of catch per trip for Chinook salmon by village.
Village

N

Min

25%

Mean

75%

Max

Akiak
Napaskiak
All

13
19
32

0
0
0

0
2
1

2
3
2

3
4
3

6
7
7

Table B3. Summary of catch rates for chum/sockeye salmon by village (units are catch per 150 feet of net soaked for 1 hour).
Village

N

Min

25%

Mean

75%

Max

Akiak
Napaskiak
All

13
19
32

5
4
4

16
7
11

36
52
46

55
74
64

72
170
170

5

Table B4. Summary of catch per trip for chum/sockeye salmon by village.
Village

N

Min

25%

Mean

75%

Max

Akiak
Napaskiak
All

13
19
32

16
11
11

24
26
24

31
49
42

35
71
58

65
111
111

Table B5. Summary of the percent of salmon catches that were Chinook salmon by village.
Village

N

Min

25%

Mean

75%

Max

Akiak
Napaskiak
All

13
19
32

0%
0%
0%

0%
3%
1%

5%
8%
7%

11%
10%
11%

15%
23%
23%

Table B6. Summary of trip start time by village.
Village
Akiak
Napaskiak
All

Min

25%

Mean

75%

Max

9:00am
9:00am
9:00am

12:00pm
10:00am
10:00am

1:25pm
10:47am
11:51am

2:15pm
11:45am
12:45pm

8:30pm
12:30pm
8:30pm

Table B7. Summary of trip end time by village.
Village
Akiak
Napaskiak
All

Min

25%

Mean

75%

Max

9:45am
10:30am
9:45am

2:10pm
11:52am
12:00pm

3:33pm
1:21pm
2:15pm

5:00pm
2:30pm
4:16pm

9:00pm
5:30pm
9:00pm

6

Table B8. Fisher’s reported progress at meeting harvest goals for Chinook salmon. The percentage is the fraction of fishers
reporting they are at or above each category after fishing on 7/5/2018.
Village

N

Under Half

Half

Over Half

Done

Akiachak
Akiak
Bethel Area Fish Camps
Kwethluk
Napaskiak
All

7
13
19
4
19
62

100%
100%
63%
100%
100%
89%

100%
92%
47%
100%
100%
82%

100%
92%
26%
100%
47%
59%

100%
50%
26%
100%
0%
36%

Table B9. Fisher’s reported progress at meeting harvest goals for chum salmon. Interpretted the same as in Table B8.
Village

N

Under Half

Half

Over Half

Done

Akiachak
Akiak
Bethel Area Fish Camps
Kwethluk
Napaskiak
All

7
13
19
4
19
62

100%
100%
89%
100%
100%
97%

100%
92%
89%
100%
100%
95%

100%
92%
84%
100%
95%
92%

100%
58%
79%
100%
58%
72%

Table B10. Fisher’s reported progress at meeting harvest goals for sockeye salmon. Interpretted the same as in Table B8.
Village

N

Under Half

Half

Over Half

Done

Akiachak
Akiak
Bethel Area Fish Camps
Kwethluk
Napaskiak
All

7
13
19
4
19
62

100%
92%
84%
100%
100%
94%

100%
92%
79%
100%
100%
92%

86%
54%
63%
100%
53%
63%

0%
23%
47%
100%
11%
29%

% of Fishers at or Above Category

Figure B1. Visual of the interviewed fishers’ reported progress at meeting harvest goals for each of the three salmon species
of interest. The height of the point/grey area is interpretted as the percent of interviewed fishers that have reportedly met at
least the category on the horizonal axis. More grey on the right indicates fishers are close to meeting needs, less grey on right
indicates fishers are far from meeting their harvest goals.
Chinook Salmon

Chum Salmon

Sockeye Salmon

100

100

100

80

80

80

60

60

60

40

40

40

20

20

20

0
Under Half

0
Half

Over Half

Done

Under Half

0
Half

Over Half

7

Done

Under Half

Half

Over Half

Done