Tuesday, August 24, 2010

Nass Update to Aug.23rd,2010

Here is the latest Nass Update to August 23, 2010. Information provided courtesy if the Nisga'a Fisheries Dept.
We have moved the steelhead section to the top for convenience.
Wonder if the mouse caught in the fishwheel was tagged and released....???


2010 NASS RIVER STOCK ASSESSMENT UPDATE – MONDAY, 23 AUGUST 2010

NASS SUMMER-RUN STEELHEAD:

Total catch of steelhead at the Nass fishwheels to date is 573 (542 anchor tagged). The GW catch (117 vs. 140 mean) of steelhead is below average based on mean catches from 1994-2009 to week ending 21 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 22 August (3,800) is below average (5,000) 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 8,000 (95% CI: 4,000, 11,000) based on in-season to post-season 94-09 linear regression relationship (r2=0.82). Using the 94-09 mean-run timing (54% to date) method, the early projection with this method is 7,000 (+/- 2 S.D: 5,000, 14,000).

The Nisga’a catch of steelhead to week ending 14 August is 468 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.

OTHER FISHWHEEL CAUGHT SPECIES:

Other catches of adult salmon and non-salmon species at the fishwheels to date include: 279 Pacific lamprey (262 tagged), 279 Dolly Varden, 199 whitefish, 93 cutthroat, 79 rainbows, 80 Northern pike minnow, 24 suckers, 16 Peamouth chubb, 8 spiny sculpins, 6 redside shiners, 2 surf smelt and 1 mouse.

The next Nass River public stock assessment update from Nisga’a Fisheries is planned for: Monday, 30 August.




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 Sunday, 22 August 2010

Meziadin Fishway counts from 28 June to 22 August are: adult sockeye (114,301 vs. 123,000 mean), and Chinook (238 vs. 336 mean) are below average, and coho (177 vs. 152 mean) are above average based on counts from 1994 to 2009. Other counts are: 1,916 tagged sockeye, 1 tagged Chinook, 2 tagged coho, 3,117 sockeye jacks (<45 cm NF length), 46 Chinook jacks (<50 cm NF length) and 19 coho jacks (<45 cm NF length).



Seaskinnish weir counts (net upstream) from 17 July to 22 August are: 77 adult coho (2 tags), 10 adult Chinook (0 tags), 10 adult sockeye (0 tags), 7 Chinook jacks (<50 cm NF length), 4 coho jacks (<45 cm NF length), 15 adult rainbow, 4 adult Pacific lamprey (0 tags), and 4 unidentified adult trout. One adult steelhead has been counted moving downstream of weir. Other video counts are: beavers, otters, Dolly Varden char, juvenile salmon and trout, northern pike minnow, sucker, sculpin, whitefish and one small unidentified non-salmonid in the viewing box.

Kwinageese weir counts from 9 July to 21 August are: 27 adult Chinook (0 tags), 0 adult sockeye and 0 adult coho. Other adult counts are: 7 bull trout, 2 rainbow and 3 mountain whitefish. Below is a table of past year’s counts at Kwinageese for comparison. It is still too early to know stock status of sockeye or Chinook runs returning to the Upper Kwinageese River based on good counts observed after mid-to-late August in 2005 and 2006.



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 very low water levels (0.7 m vs. 1.9 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 6,448 coho. Sockeye harvesting at the fishwheels was shutdown on 24 July with a reduction in TRTC and Nisga’a entitlement estimates for Nass sockeye. A small sample of Chinook (155) were also harvested at the Grease Harbour fishwheels for morphometric length and gender 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 SOCKEYE SALMON:

Total catch of sockeye at the Nass fishwheels to date is 24,655 adults (6,014 tagged) and 2,683 jacks. The GW catch (7,000 vs. 15,000 mean) of adult sockeye is below average based on mean catches from 1994-2009 to week ending 21 August. The GW catch (881 vs. 980) of jack sockeye is below 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 22 August (206,500) is tracking below average (265,000) 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 17 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 218,000 (95% CI: 186,000, 251,000) based on in-season to post-season 93-09 linear regression relationship (r2=0.99). Using the 94-09 mean-run timing (95% to date) method, the projection is 216,000 (+/- 2 S.D: 201,000, 235,000). 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 ~20% (45,000) 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., 4 August – 175,000 (fishwheel) vs. 220,000 (Meziadin) estimates). The tag retention rate being used is based on tag removals from in-river fisheries during mid-July and other tag associated losses.

Using the 94-09 mean run timing to GW fishwheels (95%), in-season net escapement (~177,000) and total Canadian catch (~147,000) estimates to date, the in-season TRTC estimate being used by Nisga’a Fisheries for Nass sockeye is ~339,000 (Min/Max ranges: 328,000, 378,000). Note that the final TRTC estimate will likely be higher if the final Meziadin mark rate data continues to track the same as above when compared to the in-season fishwheel mark rate. DFO’s Bayesian Total Nass sockeye run estimate using Alaskan Tree Point catch data to 20 August is 570,000 (95% C.I. = 360,000, 902,000). Assuming a mean harvest of ~160,000 Nass sockeye in Alaskan fisheries in 2010, the TRTC point estimate is higher than projected, ~410,000; however this estimate may be affected by the lack of commercial fishing effort in Area 3 compared to other years.

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 ~56,000 (Min/Max ranges: 54,000, 66,000).

Nisga’a domestic (FSC) fisheries continue with current catch monitoring results up to 14 August. Catch results up to 21 August will be available on Wednesday, 25 August. FSC catches to week ending 14 August are currently above average for sockeye (32,348 vs. 25,000 mean), coho (1,610 vs. 1,400 mean) and steelhead (468 vs. 175 mean – note atypical high abundance of steelhead encountered in early spring months); and below average for Chinook (4,200 vs. 5,700 mean), pink (848 vs. 1,400 even year mean) and chum (70 vs. 550 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 salmon and steelhead catch estimates in Nisga’a fisheries to date are: 66,166 sockeye, 4,375 Chinook, 8,104 coho, 2,186 pink, 70 chum and 468 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 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 21 August are: 7,030 adult sockeye (43 tags recovered), 87 adult Chinook (1 tag recovered), 7 jack Chinook, and 125 adult coho (1 tag recovered). The total adult sockeye harvested includes a commercial harvest of sockeye (3,000) by the Gitanyow below the Meziadin Fishway as part of DFO’s Inland Demonstration Fishery that occurred from 13-18 August.

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 (58,000 vs. 85,000 mean); about average for Chinook (1,370 vs. 1,400 mean) and coho (17,000 vs. 18,000 mean); and above average for pink (475,000 vs. 330,000 mean) and chum (287,000 vs. 176,000 mean) based on catch data from 2000 to 2009. The total salmon catch estimates to date in Alaskan Districts 101-104 by gillnet and seine are approximately: 3,300 Chinook, 236,000 sockeye, 195,000 coho, 8,848,000 pink and 901,000 chum salmon. Of the total in-season sockeye catch reported, approximately 62,000 (26%) 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 1,125 adults (359 tagged) and 674 jacks. The GW catch (332 vs. 1,735) of adult Chinook is well below average based on mean catches from 1994-2009 to week ending 21 August. The GW catch (186 vs. 180) of jack Chinook is just above 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 22 August (8,369) is well below average (23,000) 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, 9,100) 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 (99%), 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 14,500 (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 ~4,500 (Min/Max ranges: 4,400, 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 4,375. FSC catches to week ending 14 August are below average for Chinook (4,375 vs. 5,700 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 ~90,000, 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 ~3,300. Source of Alaskan commercial catch information is from the Alaskan Department of Fish and Game (ADFG) website.

NASS COHO SALMON:

Total catch of coho salmon at the Nass fishwheels to date is 10,174 (2,634 tagged) and 1,526 jacks. The GW catch (3,100 vs. 2,400 mean) of adult coho is above average based on mean catches from 1994-2009 to week ending 21 August. The GW catch (234 vs. 108) 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 22 August (94,000) is tracking well above average (52,000) 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 15 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 383 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 153,000 (95% CI: 104,000, 203,000) based on in-season to post-season 94-09 linear regression relationship (r2=0.90). Using the 94-09 mean-run timing (66% to date) method, the projection with this method is 142,000 (+/- 2 S.D: 107,000, 212,000).

Using the 94-09 mean run timing to GW fishwheels (66%), in-season net escapement (~161,000 – coastal and in-river estimate) and total Canadian catch (~12,000) estimates to date, the in-season TRTC estimate being used by Nisga’a Fisheries for Nass coho is ~261,000 (Min/Max ranges: 202,000, 375,000). Based on the preliminary TRTC estimate, the in-season Nisga’a share of Nass coho is estimated at ~19,000 (Min/Max ranges: 16,200, 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 8,104. FSC catches to week ending 14 August are above average for coho (1,610 vs. 1,400 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 to 15 August. 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. Source of Canadian commercial catch data is from DFO Prince Rupert. The total in-season harvest estimate of coho in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~195,000. Source of Alaskan commercial catch information is from the Alaskan Department of Fish and Game (ADFG) website. 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 3,950. The GW catch (1,500 vs. 6,000 mean) of pink is well below average based on mean catches for even years from 1994-2009 to week ending 21 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 2,186. FSC catches to week ending 14 August are below average for pink (848 vs. 1,400 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 for pinks is ~2,000 to 15 August. Source of Canadian commercial catch data is from DFO Prince Rupert. The total in-season harvest estimate of pink salmon in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~8,848,000. Source of Alaskan commercial catch information is from the Alaskan Department of Fish and Game (ADFG) website.

NASS CHUM SALMON:

Total catch of chum salmon at the Nass fishwheels to date is 56 (53 operculum tagged). The GW catch (26 vs. 50 mean) of chum is below average based on mean catches from 1994-2009 to week ending 21 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 70. FSC catches to week ending 14 August are below average for chum (70 vs. 550 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. Source of Canadian commercial catch data is from DFO Prince Rupert. The total in-season harvest estimate of chum salmon in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~901,000. Source of Alaskan commercial catch information is from the Alaskan Department of Fish and Game (ADFG) website.

No comments: