Latest Nass Update to July 25, 2010

Here is the Nass Upodate to July 25, 2010. Information courtesy of the Nisga'a Fisheries Dept.


2010 NASS RIVER STOCK ASSESSMENT UPDATE – SUNDAY 25 JULY 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 24 July 2010

Meziadin Fishway began operations on 28 June. Counts to date of adult sockeye (47,000 vs. 53,000) and Chinook (120 vs. 90) are average for sockeye and above average for Chinook based on counts from 1994 to 2009. Other counts are: 929 tagged sockeye, 535 sockeye jacks (<45 cm NF length), 1 tagged Chinook and 16 Chinook jacks (<50 cm NF length).

Kwinageese weir began operations on 9 July. Counts to 17 July are: 16 adult Chinook (0 tags) and 0 sockeye.

Seaskinnish weir began operations on 17 July. Counts to 20 July are: 2 adult rainbow, 1 beaver and 1 adult Pacific lamprey.

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) began operation below Gitwinksihlkw on 1 June for applying additional Chinook tags as part of the Nass Chinook Sentinel Stock Program and will be moved to Grease Harbour next week. All fish caught at the GW fishwheels will be released in 2010. Over the past five days, daily catches of salmon at the Gitwinksihlkw fishwheels have remained steady for sockeye (averaging ~110 per day), low for Chinook (averaging <2 per day) and chum (averaging <1 per day), and increasing for coho (averaging ~5 per day), pink (averaging ~5 per day) and steelhead (averaging ~2 per day).

Fishwheels 1 and 2 are currently operating at below average water levels (2.0 m vs. 2.5 m average (94-09)).

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

Three fishwheels (FW#3, 5 and 6) are operating at Grease Harbour (upstream of Ts'im Anwiihlist) for in-season mark-recapture tag recoveries and for some selective harvesting of sockeye, Chinook and/or coho salmon to begin in July and/or August 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) and 7 June (FW#3 and FW#6).

Selective harvesting of sockeye and coho at the Grease Harbour fishwheels began on 5 July. Harvests to date are: 6,023 sockeye and 23 coho. Sockeye harvesting in now closed with a reduction in TRTC and entitlement estimates for Nass sockeye. A small sample of Chinook (148) were harvested at the Grease Harbour fishwheels for morphometric length research as part of the Nass Chinook Sentinel Stock Program. The Chinook were distributed to the elders and community food programs. Over the past five days, daily catches of salmon at the Grease Harbour fishwheels have been steady for sockeye (averaging ~260 per day), low for Chinook (averaging ~5 per day) and chum (averaging <1 per day), and increasing for coho (averaging ~5 per day), pink (averaging ~1 per day), and steelhead (averaging ~1 per day).

NASS SOCKEYE SALMON:

Total catch of sockeye at the Nass fishwheels to date is 12,837 adults (4,126 tagged) and 1,488 jacks. The GW catch (4,804 vs. 10,700 mean) of adult sockeye is currently below average based on mean catches from 1994-2009 to week ending 24 July. The GW catch (686 vs. 570) of jack sockeye is currently above average.

The recommended run size target for adult Nass sockeye to Gitwinksihlkw 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 24 July (120,000) is currently tracking below average (163,000) 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 19 July. Mark-recapture (and best estimates of current run size) will fluctuate over a 5 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 226,000 (95% CI: 135,000, 363,000) based on in-season to post-season 93-09 linear regression relationship (r2=0.85) based on poor catches at GW fishwheels over the last five days. Using the 94-09 mean-run timing method, the projection is 205,000 (+/- 2 S.D: 155,000, 303,000). A chart is attached to show the daily projections since mark-recapture estimates started on 28 June.

Using the 93-09 mean run timing to GW fishwheels (58%), in-season net escapement (~99,000) and total Canadian catch (~117,000) estimates to date, the TRTC estimate being used by Nisga’a Fisheries for Nass sockeye is 380,000 (Min/Max ranges: 301,000, 501,000). DFO’s Bayesian Total Nass sockeye run estimate using Alaskan Tree Point catch data to 22 July was 530,000 (95% C.I. = 290,000 to 969,000). Assuming a harvest between 120,000 and 160,000 Nass sockeye in Alaskan fisheries in 2010, the TRTC point estimate would range between 370,000 and 410,000.

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. The pre-season target was ~113,000 based on the sibling forecast method. The in-season target is estimated at ~55,000 sockeye to date based on the in-season TRTC estimate.

Nisga’a domestic (FSC) fisheries continue with current catch monitoring results up to 17 July. Catch results up to 24 July will be available on Wednesday, 28 July. FSC catches to week ending 17 July are currently just above average for coho (41 vs. 25) and steelhead (323 vs. 62 – note atypical high abundance of steelhead detected in early spring months); average for sockeye (13,780 vs. 13,130); and below average for Chinook (3,891 vs. 5,000), pink (104 vs. 400 even year) and chum (38 vs. 200) based on mean catch monitoring results from 2000 to 2009.

Four Nisga’a marine sale fisheries in Area 3-12 have occurred to date 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, 30 Coho, 9 coho, and 1,327 pink. Four Nisga’a in-river sale fisheries have occurred to date on 12 July, 14 July 16 July and 22 July. Total in-river sale catches to date are: 17,928 sockeye and 41 coho. Results of each fishery are provided in the attachment (pg 2 summary).

Nisga’a Fisheries will make an announcement on Monday, 26 July regarding the status of the Nass sockeye run and entitlement share. All sockeye sale fisheries will be shutdown until further notice due to the current estimates.

Total in-season catch estimates in Nisga’a fisheries to date are: 49,037 sockeye, 4,096 Chinook, 114 coho, 1,431 pink, 38 chum and 323 steelhead.

Area 3 commercial fisheries conducted in 2010 to date: Eight 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) and 13 July (107 boats)] and two seine [12 July (9 boats) and 13 July (9 boats)]. Total in-season commercial harvest estimates in Area 3 to date are: 64,373 sockeye; 0 coho (2,315 released); 30,174 pink (126 released); 15,388 chum (15,301 released) and 694 Chinook (317 released). DFO have announced a commercial fishery for both gillnets and seines in Area 3 on Monday, 26 July. Area 4 will also open on 26 July to gillnets which will reduce the number of boats fishing in Area 3. Source of commercial information is courtesy of DFO Prince Rupert Fisheries Management.

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 below average for sockeye (32,000 vs. 66,000 mean) and coho (5,700 vs. 7,800 mean); average for Chinook (1,250 vs. 1,300 mean); and above average for pink (106,000 vs. 89,000 mean) and chum (215,000 vs. 122,000 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: 126,500 sockeye, 2,550 Chinook, 93,500 coho, 781,500 pink and 605,800 chum salmon. Of the total sockeye catch, approximately 38,700 (31%) 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 1,049 adults (342 tagged) and 613 jacks. The GW catch (312 vs. 1,675) of adult Chinook is below average based on mean catches from 1994-2009 to week ending 24 July. The GW catch (179 vs. 160) 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 24 July (7,900) is well below average (22,000) 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 is being used to generate the current run size estimates for Chinook. The run size projection for Upper Nass Chinook to GW to date is 9,000 (95% CI: 7,300, 9,800) based on in-season to post-season estimates, 93-09 linear regression relationship (r2=1.00).

Using the 94-09 mean run timing to GW fishwheels (95%), in-season net escapement (~7,100 – coastal and in-river estimate) and total Canadian catch (~7,800) estimates to date, the TRTC estimate for Nass Chinook is 15,600 (Min/Max ranges: 15,000, 16,000).

The total Nisga’a harvest estimate of Nass Chinook to date is 4,096. FSC catches to week ending 17 July are below average for Chinook (3,891 vs. 5,000) based on mean catch monitoring results from 2000 to 2009.

Area 3 commercial net fishery harvests of Chinook to date is 694 (317 released). The total in-season harvest estimate of Chinook in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~2,550.

NASS COHO SALMON:

Total catch of coho salmon at the Nass fishwheels to date is 76 (32 tagged) and 16 jacks. The GW catch (37 vs. 37 mean) of adult coho is average based on mean catches from 1994-2009 to week ending 24 July. The GW catch (16 vs. 9) 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 is ~60,000.

The Nass coho in-season run size estimate to Gitwinksihlkw to 24 July (1,300) is currently tracking above average (650) based on a mean run size to Gitwinksihlkw of 82,000 from 1994 to 2009. The run size estimate is currently a historical catch index estimate until enough tag recoveries at the Grease Harbour fishwheels occur to start generating an independent in-season mark-recapture estimate. Three catchability index ranges are shown in the attachment based on: 1) mean catchability (4.3%), 2) low water/low catchability (2.8%) and 3) high water/high catchability (6.5%). The low water-low catchability estimate is being used to generate the current run size estimates for coho. The run size projection for Upper Nass Coho to GW to date is 118,000 (95% CI: 46,000, 190,000) based on in-season to post-season estimates, 94-09 linear regression relationship (r2=0.47).

Pre-season TRTC forecasts for Nass coho range between 104,000 (minimum brood estimate) and 127,000 (maximum brood estimate). Based on the pre-season TRTC forecasts and the minimum escapement goal (40,000), the Nisga’a pre-season allocation ranges between 8,000 and 10,000 for Nass Area coho. The mean brood pre-season TRTC estimate (115,000) will be used for calculating the initial target for the in-season Nisga’a allocation (9,000). This target will be adjusted during the season based on in-season assessments. The actual allocation target may be up to 7,000 more to account for management uncertainty allowances as part of the overage/underage calculations from 2000 to 2009. Underages would only be targeted in a productive return year as assessed during the season. It is too early to project TRTC estimate for Nass coho based on <1% return to date (94-09 mean run timing).

The total Nisga’a harvest estimate of Nass coho to date is 114. FSC catches to week ending 17 July are average for coho (41 vs. 25 mean) based on mean catch monitoring results from 2000 to 2009.

Area 3 commercial net fishery harvests of coho to date is 0 (2,315 released). The total in-season harvest estimate of coho in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~93,500.

NASS PINK SALMON:

Total catch of pink salmon at the Nass fishwheels to date is 94. The GW catch (48 vs. 400 mean) of pink is below average based on mean catches for even years from 1994-2009 to week ending 24 July.

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 0 and 2,000 for Nass Area pinks. No cumulated overages or underages exist from 2000 to 2009.

The total Nisga’a harvest estimate of Nass pink salmon to date is 1,431. FSC catches to week ending 17 July are just below average for pink (104 vs. 400 mean even year) 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 30,174 (126 released). The total in-season harvest estimate of pink salmon in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~781,500.

NASS CHUM SALMON:

Total catch of chum salmon at the Nass fishwheels to date is 12. The GW catch (6 vs. 5 mean) of chum is average based on mean catches from 1994-2009 to week ending 24 July.

Pre-season TRTC forecasts for Nass Area chums range between 19,000 (minimum brood estimate) and 107,000 (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 0 and 8,500. The actual allocation target 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 500 in 2010.

The total Nisga’a harvest estimate of Nass chum salmon to date is 38. FSC catches to week ending 17 July are below average for chum (38 vs. 200 mean) based on mean catch results from 2000 to 2009 catch monitoring program.

Area 3 commercial gillnet harvest of chum salmon to date is 15,388 (10,727 released). The Area 3 commercial seine fisheries released 4,574 chum to date. The total in-season harvest estimate of chum salmon in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~606,000.

NASS SUMMER-RUN STEELHEAD:

Total catch of steelhead at the Nass fishwheels to date is 30 (21 anchor tagged). The GW catch (20 vs. 11 mean) of steelhead is above average based on mean catches from 1994-2009 to week ending 24 July.

In-season run size estimates presented for 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 24 July (400) is above average (175) 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 early projected run size projection for summer-run steelhead to GW to date is 11,000 (95% CI: 1,050, 20,800) based on in-season to post-season estimates, 94-09 linear regression relationship (r2=0.12).

The Nisga’a catch of steelhead to week ending 17 July is 323 and includes spring run steelhead caught in May and June. The average harvest of Nass steelhead in the Nisga’a fishery is ~400 from 1994 to 2009 catch monitoring programs. A total of 176 steelhead have been released in the Area 3 commercial fishery to date in 2010.

OTHER FISHWHEEL CAUGHT SPECIES:

Other catches of adult salmon and non-salmon species at the fishwheels to date include: 174 Pacific lamprey (162 tagged), 130 whitefish, 77 cutthroat, 93 Dolly Varden, 45 Northern pike minnow, 45 rainbows, 19 suckers, 8 peamouth chubb, 6 redside shiners, 5 spiny sculpins, and 2 surf smelt.

Escapement updates will be available at the above website link on Tuesday, 27 July and Thursday, 29 July.

The next Nass River public stock assessment update from Nisga’a Fisheries is planned for: Monday, 2 August.