Latest Nass Update to Aug.15, 2010

Here is the latest Nass Update to Aug.15th. Information courtesy of the Nisga'a Fisheries Dept.
We copied the steelhead section to the top for convenience.


2010 NASS RIVER STOCK ASSESSMENT UPDATE – SUNDAY, 15 AUGUST 2010

Attached is a public Nass River salmon stock assessment update for 2010 (pdf format) from the Nisga’a Fisheries and Wildlife Department of Nisga’a Lisims Government. Sayt K'il'im Goot – one heart, one path, one nation.

All data presented in this update are preliminary and subject to change with further assessment information that becomes available and should be interpreted cautiously for in-season assessment purposes only.

ESCAPEMENT UPDATES AND FISHERY ANNOUNCEMENTS FROM NISGA’A FISHERIES AND WILDLIFE DEPARTMENT ARE AVAILABLE AT THE FOLLOWING LINK:

ftp://ftp.lgl.com/Nass%20Stock%20Assessment%20Updates/

It is recommended to refresh link (F5) each time & copy files to your machine before opening.

NASS FISHWHEEL, MEZIADIN FISHWAY, KWINAGEESE & SEASKINNISH WEIR OPERATIONAL NOTES:

Assessment data for fishwheels and Meziadin Fishway: Up to Saturday, 14 August 2010



Meziadin Fishway counts from 28 June to 14 August are: adult sockeye (76,218 vs. 102,000 mean), Chinook (223 vs. 288 mean) and coho (12 vs. 22 mean) are below average based on counts from 1994 to 2009. Other counts are: 1,490 tagged sockeye, 2,068 sockeye jacks (<45 cm NF length), 1 tagged Chinook, 40 Chinook jacks (<50 cm NF length) and 2 coho jacks (<45 cm NF length).

Kwinageese weir counts from 9 July to 13 August are: 26 adult Chinook (0 tags), 0 adult sockeye and 0 adult coho. Other adult counts are: 7 bull trout, 2 rainbow and 3 mountain whitefish.

Seaskinnish weir counts (net upstream) from 17 July to 14 August are: 66 adult coho (2 tags), 4 coho jack, 9 adult Chinook (0 tags), 5 Chinook jacks (<50 cm NF length), 13 adult rainbow, 3 adult sockeye (0 tags), and 3 adult Pacific lamprey (0 tags). One adult steelhead and one adult trout have been counted moving downstream of weir. Other video counts are: beavers, otters, juvenile salmon and trout, northern pike minnow, sucker, sculpin, whitefish and one small unidentified non-salmonid in the viewing box.

GITWINKSIHLKW (GW) FISHWHEELS (TEST FISHERY - 17TH YEAR):

Fishwheels 1 and 2 were started on 1 June for tagging and historical catch index assessments for salmon and steelhead. A third fishwheel (FW#7) operated below Gitwinksihlkw from 1 June to 27 July for applying additional Chinook tags as part of the Nass Chinook Sentinel Stock Program. Fishwheels 1 and 2 are currently operating at low water levels (1.4 m vs. 2.0 m mean) when compared to operational years from 1994 to 2009.

GREASE HARBOUR (GH) FISHWHEELS (~17 KM UPSTREAM OF TEST FISHERY):

Four fishwheels (FW#3, 5, 6 and now FW#4) are operating at Grease Harbour (upstream of Ts'im Anwiihlist) for in-season mark-recapture tag recoveries, additional tagging (adult steelhead, chum and Pacific lamprey), and for some selective harvesting of sockeye (ended on 24 July), Chinook (ended on 24 July) and coho salmon from July to September depending on run strength, Nisga’a entitlement levels and targets as directed by Nisga’a Lisims Government. Start-up dates of GH fishwheels were: 5 June (FW#5), 7 June (FW#3 and FW#6) and 5 August (FW#4).

Selective harvesting at the Grease Harbour fishwheels occurred for sockeye (5-24 July) and coho (17-24 July; and 6 August and continues). Harvests to date are: 6,023 sockeye and 3,558 coho. Sockeye harvesting at the fishwheels was shutdown on 24 July with a reduction in TRTC and entitlement estimates for Nass sockeye. A small sample of Chinook (155) were also harvested at the Grease Harbour fishwheels for morphometric length and sex research as part of the Nass Chinook PSC Sentinel Stock Program. The sample of Chinook were distributed to the elders and community food programs.

NASS SUMMER-RUN STEELHEAD:

Total catch of steelhead at the Nass fishwheels to date is 333 (316 anchor tagged). The GW catch (87 vs. 90 mean) of steelhead is average based on mean catches from 1994-2009 to week ending 14 August.

In-season run size estimates presented for adult Nass steelhead are only for summer runs (i.e., do not include any estimates for winter or spring run steelhead) and only cover return information from July to September when the fishwheels typically operate during summer run migration.

The Nass summer-run steelhead in-season run size estimate to Gitwinksihlkw to 14 August (3,400) is just above average (3,000) based on a mean run size to Gitwinksihlkw of 11,500 from 1994 to 2009. The run size estimate is using the same catch efficiency rates used for coho during the season. The run size projection for Nass summer-run steelhead to GW to date is 10,000 (95% CI: 5,000, 15,000) based on in-season to post-season 94-09 linear regression relationship (r2=0.65). Using the 94-09 mean-run timing (33% to date) method, the early projection with this method is 10,000 (+/- 2 S.D: 6,000, 33,000).

The Nisga’a catch of steelhead to week ending 7 August is 398 and includes spring run steelhead caught in May and June. The average harvest of Nass steelhead in the Nisga’a fishery is ~400 (range: 100 to 700) from 1993 to 2009 catch monitoring programs. Releases of steelhead in the Area 3 commercial fishery to date is 185 from gillnet and 11 from seine fisheries in 2010.


NASS SOCKEYE SALMON:

Total catch of sockeye at the Nass fishwheels to date is 22,910 adults (5,796 tagged) and 2,499 jacks. The GW catch (6,800 vs. 14,000 mean) of adult sockeye is below average based on mean catches from 1994-2009 to week ending 14 August. The GW catch (863 vs. 900) of jack sockeye is about average to date.

The recommended run size target for adult Nass sockeye to Gitwinksihlkw in 2010 is 275,000 depending on harvests projected above Gitwinksihlkw. The run size target has been set to have a greater certainty of reaching the Meziadin River escapement goal (160,000) which has represented 51% to 85% (avg. is 68%) of the total Nass sockeye aggregate population since 1994. The net aggregate escapement target is ~200,000.

The Nass sockeye in-season run size estimate to Gitwinksihlkw to 14 August (206,000) is tracking below average (251,000) based on a mean run size to Gitwinksihlkw of 278,000 from 1994 to 2009. The run size estimate is a combination of mark-recapture and historical catch indices methods. Currently, run size estimates are final to 9 August based on in-season mark recapture rates. Mark-recapture (and best estimates of current run size) will fluctuate over a five day period as additional catch and tag recovery data from the weekly GW tagging period pass the GH fishwheels. A spreadsheet of the calculations and range of estimates is provided in the attachment.

The run size projection for Nass sockeye to GW to date is 231,000 (95% CI: 173,000, 289,000) based on in-season to post-season 93-09 linear regression relationship (r2=0.96). Using the 94-09 mean-run timing (91% to date) method, the projection is 228,000 (+/- 2 S.D: 201,000, 263,000). A chart is attached to show the daily projections since mark-recapture estimates started on 28 June. Note that the current in-season run size to GW and projection estimates may be under estimated by ~15,000 when comparing the in-season fishwheel mark rate at GW versus the current Meziadin mark rate using a 18 d lag and a tag retention rate of 70% (i.e., 27 July – 146,000 (fishwheel) vs. 160,500 (Meziadin) estimate). A lower tag retention rate is being used to account for in-river fisheries that were conducted during mid-July.

Using the 94-09 mean run timing to GW fishwheels (91%), in-season net escapement (~182,000) and total Canadian catch (~140,000) estimates to date, the in-season TRTC estimate being used by Nisga’a Fisheries for Nass sockeye is ~357,000 (Min/Max ranges: 336,000, 409,000). DFO’s Bayesian Total Nass sockeye run estimate using Alaskan Tree Point catch data to 12 August is 580,000 (95% C.I. = 340,000, 989,000). Assuming a harvest between 120,000 and 160,000 Nass sockeye in Alaskan fisheries in 2010, the TRTC point estimate is higher than projected, ranging between 420,000 and 460,000; however this estimate may be affected by the lack of commercial fishing effort in Area 3.

Based on the pre-season TRTC forecasts and the minimum escapement goal (100,000), the Nisga’a pre-season allocation for Nass sockeye ranges between 52,000 and 118,000. Based on the in-season TRTC estimate, the in-season Nisga’a share of Nass sockeye is estimated at ~53,000 (Min/Max ranges: 48,000, 70,000).

Nisga’a domestic (FSC) fisheries continue with current catch monitoring results up to 7 August. Catch results up to 14 August will be available on Wednesday, 18 August. FSC catches to week ending 7 August are currently above average for sockeye (30,654 vs. 23,000 mean), coho (828 vs. 600 mean) and steelhead (398 vs. 150 mean – note atypical high abundance of steelhead encountered in early spring months); and below average for Chinook (4,009 vs. 5,600 mean), pink (732 vs. 1,100 even year mean) and chum (68 vs. 400 mean) based on mean catch monitoring results from 2000 to 2009.

Four Nisga’a marine sale fisheries in Area 3-12 were conducted on 2 July (29 boats), 9 July (29 boats), 10 July (21 boats) and 17 July (28 GN and 1 SN). Total marine sale catches to date are: 11,306 sockeye, 28 Chinook, 9 coho, and 1,338 pink. Four Nisga’a in-river sale fisheries were conducted on 12 July, 14 July, 16 July and 22 July. Total in-river sale catches to date are: 16,489 sockeye and 37 coho. All Nisga’a sockeye sale fisheries are shutdown due to the current TRTC and Nisga’a entitlement estimates.

Total in-season catch estimates in Nisga’a fisheries to date are: 64,472 sockeye; 4,284 Chinook; 4,432 coho; 2,070 pink, 68 chum and 398 steelhead.

Area 3 commercial fisheries conducted in 2010 to date: Nine gillnet [15 June (150 boats), 21 June (164 boats), 28 June (216 boats), 29 June (216 boats), 5 July (228 boats), 6 July (228 boats), 12 July (56 boats), 13 July (107 boats) and 26 July (17 boats)] and three seine [12 July (9 boats), 13 July (9 boats) and 26 July (9 boats)]. Total in-season commercial harvest estimates in Area 3 to date are: 67,757 sockeye; 0 coho (2,852 released); 53,370 pink (126 released); 15,388 chum (18,782 released) and 694 Chinook (520 released). Areas 3 and 4 are currently closed to sockeye fisheries due to low returns of both Nass and Skeena sockeye. Source of commercial information is courtesy of DFO Prince Rupert Fisheries Management.

Gitanyow Nass salmon harvests as reported by the Gitanyow Fisheries Authority to week ending 7 August are: 2,779 adult sockeye (30 tags recaps reported), 73 adult Chinook (1 tag recovery reported), 7 jack Chinook, and 10 adult coho (0 tags). A commercial harvest of sockeye by the Gitanyow below the Meziadin Fishway was approved by DFO, as part of DFO’s Inland Demonstration Fishery, and began on 12 August. The anticipated commercial harvest is 3,000 sockeye.

Alaskan gillnet fisheries in Districts 101 (Tree Point) and 106 (Sumner and Upper Clarence) began on 20 June and 21 June, respectively. Alaskan seine fisheries opening dates are: District 101 (Revilla & Lower Clarence) – 4 July; District 102 (Middle Clarence) – 21 June; District 103 (Cordova) – 25 July; and District 104 (Noyes and Dall) - 4 July. Total gillnet catches at Tree Point to date are well below average for sockeye (56,000 vs. 84,000 mean); about average for Chinook (1,350 vs. 1,400 mean) and coho (15,000 vs. 15,500 mean); and above average for pink (392,000 vs. 275,000 mean) and chum (283,000 vs. 168,000 mean) based on catch data from 2000 to 2009. The total salmon catch estimate to date in districts 101-104 by gillnet and seine are approximately: 3,125 Chinook, 216,000 sockeye, 148,000 coho, 5,418,000 pink and 806,000 chum salmon. Of the total sockeye catch reported, approximately 60,000 (27%) are estimated as Nass origin based on mean stock composition estimates from 1982 to 2007. Source of Alaskan commercial catch information is from the Alaskan Department of Fish and Game (ADFG) website.

NASS CHINOOK SALMON:

Total catch of Chinook salmon at the Nass fishwheels to date is 1,121 adults (358 tagged) and 670 jacks. The GW catch (330 vs. 1,725) of adult Chinook is well below average based on mean catches from 1994-2009 to week ending 14 August. The GW catch (185 vs. 180) of jack Chinook is average.

The recommended in-season run size target for adult Nass Chinook to Gitwinksihlkw in 2010 is 17,000 depending on harvests projected above GW. The net escapement target is ~15,000.

The Nass Chinook in-season run size estimate to Gitwinksihlkw to 14 August (8,331) is well below average (22,700) based on a mean run size to Gitwinksihlkw of 23,000 from 1994 to 2009. The run size is estimated based on catch indices where the cumulative daily catch of Chinook at FW1 and FW2 is multiplied by a catchability expansion factors from 1994-2009 post-season results depending on daily water levels. Three catchability index ranges are shown in the attachment based on: 1) mean catchability (7.6%), 2) low water/low catchability (3.9%) and 3) high water/high catchability (12.6%). The low water-low catchability estimate has been used to generate the majority of the daily run size estimates for Chinook in 2010. The run size projection for Upper Nass Chinook to GW to date is 9,000 (95% CI: 8,100, 9,200) based on in-season to post-season estimates, 94-09 linear regression relationship (r2=1.00). Note: the in-season Chinook run size and projection estimates are typically under estimated each year by ~25% so the final run size (and TRTC) estimates are expected to be higher.

Using the 94-09 mean run timing to GW fishwheels (98%), in-season net escapement (~7,500 – coastal and in-river estimate) and total Canadian catch (~7,000) estimates to date, the TRTC estimate for Nass Chinook is 14,600 (Min/Max ranges: 14,000, 15,000). Based on the in-season TRTC estimate, the in-season Nisga’a share of Nass Chinook is estimated at ~4,600 (Min/Max ranges: 4,500, 4,700). The actual allocation share may be up to ~4,000 more for management uncertainty allowances as part of the overage/underage calculations from 2000 to 2009. However, the management uncertainty underage amount was not targeted in 2010 due to the poor return.

The total Nisga’a harvest estimate of Nass Chinook to date is 4,284. FSC catches to week ending 7 August are below average for Chinook (4,009 vs. 5,600 mean) based on mean catch monitoring results from 2000 to 2009.

Area 3 commercial net fishery harvests of Chinook to date is 694 (520 released). Areas 1 and 2 reported total Chinook harvests in the recreational and troll fishery is ~45,000 and ~64,000, respectively. DNA analyses of the troll catch indicated that Nass chinook made up 0.6% and 0.8% in the two early samples, and 0% in the subsequent samples. Source of catch and DNA information from DFO Prince Rupert. The total in-season harvest estimate of Chinook in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~3,200.

NASS COHO SALMON:

Total catch of coho salmon at the Nass fishwheels to date is 6,463 (1,853 tagged) and 1,176 jacks. The GW catch (2,183 vs. 1,500 mean) of adult coho is above average based on mean catches from 1994-2009 to week ending 14 August. The GW catch (206 vs. 100) of jack coho is above average.

The recommended in-season run size target for adult Nass coho to Gitwinksihlkw in 2010 is 65,000 depending on harvests projected above GW. The net escapement target to the Upper Nass is ~60,000. The Nass coho in-season run size estimate to Gitwinksihlkw to 14 August (82,000) is tracking well above average (31,000) based on a mean run size to Gitwinksihlkw of 82,000 from 1994 to 2009. The run size estimate is a combination of mark-recapture and historical catch indices methods. Currently, run size estimates are final to 7 August based on in-season mark recapture rates. Mark-recapture (and best estimates of current run size) will fluctuate over a seven day period as additional catch and tag recovery data from the weekly GW tagging period pass the GH fishwheels. A total of 173 tag recaps are being used for in-season mark rate determination. A spreadsheet of the calculations and range of estimates is provided in the attachment.

The run size projection for Nass adult coho to GW to date is 201,000 (95% CI: 100,000, 303,000) based on in-season to post-season 94-09 linear regression relationship (r2=0.71). Using the 94-09 mean-run timing (40% to date) method, the projection with this method is 204,000 (+/- 2 S.D: 132,000, 441,000).

Using the 94-09 mean run timing to GW fishwheels (40%), in-season net escapement (~144,000 – coastal and in-river estimate) and total Canadian catch (~10,000) estimates to date, the in-season TRTC estimate being used by Nisga’a Fisheries for Nass coho is ~379,000 (Min/Max ranges: 251,000, 727,000). Based on the preliminary TRTC estimate, the in-season Nisga’a share of Nass coho is estimated at ~19,200 (the maximum treaty amount with Min/Max ranges: 19,200, 19,200). The actual allocation share may be up to 8,000 more depending on run strength to account for management uncertainty allowances as part of the overage/underage calculations from 2000 to 2009.

The total Nisga’a harvest estimate of Nass coho to date is 4,432. FSC catches to week ending 7 August are above average for coho (828 vs. 600 mean) based on mean catch monitoring results from 2000 to 2009.

Area 3 commercial net fishery harvests of coho to date is 0 (2,852 released). Areas 1 and 2 reported coho harvests in the recreational fishery is ~15,000. The total projected catch of coho in troll fisheries is anticipated at ~56,000 with ~90% expected to be caught in Areas 1 and 2. The total in-season harvest estimate of coho in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~148,000. The Nass component in the northern commercial fisheries is unknown.

NASS PINK SALMON:

Total catch of adult pink salmon at the Nass fishwheels to date is 2,789. The GW catch (1,222 vs. 4,600 mean) of pink is well below average based on mean catches for even years from 1994-2009 to week ending 14 August.

Pre-season TRTC forecasts for Nass pinks range between 68,000 (minimum brood estimate) and 230,000 (maximum brood estimate) for even year, two year return average. Based on the pre-season TRTC forecasts and the minimum escapement goal (150,000), the Nisga’a allocation ranges between 500 and 2,000 for Nass Area pinks. No cumulated overages or underages exist from 2000 to 2009. In-season TRTC estimates for Nass pink salmon are under assessment and will be based on any coastal stream inspections conducted and provided by DFO.

The total Nisga’a harvest estimate of Nass pink salmon to date is 2,070. FSC catches to week ending 7 August are below average for pink (732 vs. 1,100 even year mean) based on mean catch results from 2000 to 2009 catch monitoring program for even year returns.

Area 3 commercial net fishery harvests of pink salmon to date is 53,370 (126 released). Areas 1 and 2 recreational catch estimates to date for pinks is ~2,000. The total in-season harvest estimate of pink salmon in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~5,418,000.

NASS CHUM SALMON:

Total catch of chum salmon at the Nass fishwheels to date is 40 (36 tagged). The GW catch (20 vs. 30 mean) of chum is below average based on mean catches from 1994-2009 to week ending 14 August.

Pre-season TRTC forecasts for Nass Area chums range between 19,000 (minimum brood estimate) and 108,000 (maximum brood estimate). Based on the pre-season TRTC forecasts and the minimum escapement goal (30,000), the Nisga’a allocation of Nass Area chums ranges between 1,500 and 8,600. In-season TRTC estimates for Nass Chum salmon are under assessment and will be based on any coastal stream inspections conducted and provided by DFO. The actual Nisga’a share of Nass Area chum may be up to 36,000 more to account for overage/underage allowances from 2000 to 2009. However, Nass Area chum will not be targeted in Nisga’a fisheries to promote rebuilding of stocks in Area 3 and assisting in addressing one of the conditions of the MSC certification recently awarded to the Nass sockeye fishery. Nisga’a FSC harvest of chum will be minimal and is anticipated to reach between 100 and 300 in 2010.

The total Nisga’a harvest estimate of Nass chum salmon to date is 68. FSC catches to week ending 7 August are below average for chum (68 vs. 400 mean) based on mean catch results from 2000 to 2009 catch monitoring program.

Area 3 commercial gillnet harvest of chum salmon is 15,388 (10,982 released). The Area 3 commercial seine fisheries released 7,800 chum. The total in-season harvest estimate of chum salmon in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~806,000.


OTHER FISHWHEEL CAUGHT SPECIES:

Other catches of adult salmon and non-salmon species at the fishwheels to date include: 259 Pacific lamprey (223 tagged), 240 Dolly Varden, 180 whitefish, 89 cutthroat, 71 rainbows, 65 Northern pike minnow, 22 suckers, 10 Peamouth chubb, 8 spiny sculpins, 6 redside shiners, 2 surf smelt and 1 mouse.

An escapement update will be available at the above website link on Thursday, 19 August.

The next Nass River public stock assessment update from Nisga’a Fisheries is planned for: Monday, 23 August.