Nass Update to July 18, 2010

Here is the latest Nass Update to July 18, 2010. Information courtesy of Nisga'a Fisheries.
Interesting info from the fishwheels and video monitoring at weirs.For example, at the Seaskinnish video-counting weir counts to date include 2 adult rainbow and 1 beaver.
Or these catches at fishwheels: 151 Pacific lamprey, 93 whitefish, 69 cutthroat, 50 Dolly Varden, 44 Northern pike minnow, 36 rainbows, 17 suckers, 4 spiny sculpins, and 2 long-fin smelt.


2010 NASS RIVER STOCK ASSESSMENT UPDATE – SUNDAY 18 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, Meziadin Fishway and weir projects: Up to Saturday 17 July 2010

Meziadin Fishway began operations on 28 June. Counts of adult sockeye (31,498 vs. 29,000) and Chinook (58 vs. 35) are above average (94-09) to date. Other counts are: 661 tagged sockeye, 101 sockeye jacks (<45 cm NF length) and 8 Chinook jacks (<50 cm NF length).

Kwinageese video-counting weir began operations on 9 July. Counts to date are: 8 adult Chinook (0 tags) and 0 sockeye.

Seaskinnish video-counting weir began operations on 17 July. Counts to date are: 2 adult rainbow and 1 beaver.

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 only operate in June and a portion of July once the majority of Chinook have passed GW. All fish caught at the GW fishwheels will be released in 2010. Daily catches of salmon at the Gitwinksihlkw fishwheels have dropped substantially for sockeye (averaging ~100 per day) and remain low for Chinook (averaging <2 per day) over the past five days.

Fishwheels 1 and 2 are currently operating at the lowest water levels experienced over the seventeen year period of the program (1.5 m vs. 2.7 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: 4,557 sockeye and 1 coho. 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. Daily catches of salmon at the Grease Harbour fishwheels have dropped significantly for sockeye (averaging ~250 per day) and low numbers of Chinook (averaging <10 per day), coho (averaging <1 per day) and pink (averaging <2 per day) have been caught over the past five days.

NASS SUMMER-RUN STEELHEAD:

Total catch of steelhead at the Nass fishwheels to date is 18. The GW catch (12 vs. 7 mean) of steelhead is above average based on mean catches from 1994-2009 to week ending 17 July. The first summer run steelhead caught since 24 June was on 16 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 in-season Nass summer-run steelhead run size estimate to Gitwinksihlkw to 17 July (45) is currently tracking above average (60) based on a mean run size to Gitwinksihlkw of 11,400 from 1994 to 2009.

The run size estimate is currently a historical catch index estimate based on coho results from 1994 to 2009 until enough tag recoveries at the Grease Harbour fishwheels occur to start generating an independent in-season mark-recapture estimate. Mark rates derived from the coho assessment program are used to generate summer-run steelhead estimates that assume similar catchability between coho and steelhead at the GW fishwheels based on similar run timing patterns. Mark-rate sample sizes are much larger and more reliable for coho than using steelhead mark rate data.

The Nisga’a catch of steelhead to week ending 10 July is 306 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 139 steelhead have been released in the Area 3 commercial net fishery to date in 2010.



NASS SOCKEYE SALMON:

Total catch of sockeye at the Nass fishwheels to date is 10,529 adults (3,530 tagged) and 1,216 jacks. The GW catch (4,142 vs. 8,800 mean) of adult sockeye is currently below average based on mean catches from 1994-2009 to week ending 17 July. The GW catch (645 vs. 420) of jack sockeye is currently above average.

The recommended run size target for adult Nass sockeye to Gitwinksihlkw is 275,000. 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 17 July (113,000) is currently tracking below average (132,000) 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 12 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 17 July is 254,000 (95% CI: 145,000, 363,000) based on in-season to post-season 93-09 linear regression relationship (r2=0.78). Using the 94-09 mean-run timing method, the projection is 238,000 (+/- 2 S.D: 168,000, 408,000). 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 (47%), in-season net escapement (~98,000) and total Canadian catch (~117,000) estimates to 17 July, the TRTC estimate being used by Nisga’a Fisheries for Nass sockeye is 452,000 (Min/Max ranges: 347,000, 607,000). DFO’s Bayesian Total Nass sockeye run estimate using Alaskan Tree Point catch data to 14 July was 570,000 (95% C.I. = 390,000 to 833,077). If we assume that between 120,000 and 160,000 Nass sockeye will be harvested in Alaskan fisheries in 2010 then the TRTC point estimate is reasonable for an in-season forecast to date using two different methods.

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 ~71,000 sockeye to date based on the in-season TRTC estimate.

Nisga’a domestic (FSC) fisheries continue with current catch monitoring results up to 10 July. Catch results up to 17 July will be available on Wednesday, 21 July. FSC catches to week ending 10 July are currently just above average for sockeye (11,104 vs. 10,150) and steelhead (306 vs. 50); average for coho (8 vs. 9); and below average for Chinook (3,529 vs. 4,600), pink (41 vs. 53) and chum (30 vs. 100) 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 Chinook, 9 coho, and 1,327 pink. Three Nisga’a in-river sale fisheries have occurred to date on 12 July, 14 July and 16 July. Total in-river sale catches to date are: 11,243 sockeye and 10 coho. Results of each fishery is provided in the attachment (pg 2 summary).

Nisga’a Fisheries will make an announcement updating on potential sale fishery openings on Monday, 19 July (2 pm) for in-river and Wednesday, 21 July (2 pm) for marine.

Total in-season catch estimates in Nisga’a fisheries to date are: 38,210 sockeye, 3,772 Chinook, 28 coho, 1,368 pink, 30 chum and 306 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: 64,275 sockeye; 0 coho (2315 released); 30,019 pink (126 released); 15,388 chum (15,301 released) and 693 Chinook (317 released). Next announcement from DFO regarding potential openings in Area 3 will be on Thursday, 22 July. 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) – not open yet; and District 104 (Noyes and Dall) - 4 July. Total gillnet catches at Tree Point to date are below average for sockeye (27,981 vs. 58,000 mean) and pink (71,199 vs. 100,000 mean); average for Chinook (1,217 vs. 1,200 mean) and coho (5,302 vs. 5,600 mean); and above average for chum (184,000 vs. 95,000 mean) based on catch data from 2000 to 2009. The total salmon catch estimate in all districts to date are approximately: 99,256 sockeye, 2,452 Chinook, 82,822 coho, 430,149 pink and 500,018 chum salmon. Of the total sockeye catch, approximately 33,000 (33%) 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 1,011 adults (336 tagged) and 551 jacks. The GW catch (306 vs. 1,640) of adult Chinook is below average based on mean catches from 1994-2009 to week ending 17 July. The GW catch (174 vs. 150) 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 17 July (7,754) is well below average (21,500) 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 17 July is 9,000 (95% CI: 6,500, 11,000) based on in-season to post-season estimates, 93-09 linear regression relationship (r2=0.99).

Using the 94-09 mean run timing to GW fishwheels (93%), in-season net escapement (~7,100 – coastal and in-river estimate) and total Canadian catch (~7,800) estimates to 17 July, the TRTC estimate for Nass Chinook is ~16,000 (Min/Max ranges: 15,000, 18,000).

The total Nisga’a harvest estimate of Nass Chinook to date is 3,772. FSC catches to week ending 10 July are below average for Chinook (3,529 vs. 4,600) based on mean catch monitoring results from 2000 to 2009. Nisga’a FSC harvest of Chinook is anticipated to reach between 4,000 and 6,000 in 2010.

Area 3 commercial net fishery harvests of Chinook to date is 693 (317 released). The total in-season harvest estimate of Chinook in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~2,500.

NASS COHO SALMON:

Total catch of coho salmon at the Nass fishwheels to date is 7 (3 tagged) and 2 jacks. The GW catch (4 vs. 4 mean) of adult coho is average based on mean catches from 1994-2009 to week ending 17 July. The GW catch (1 vs. 1) of jack coho is 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 17 July (144) is currently tracking above average (60) 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. It is too early to project a run size estimate for Upper Nass coho to GW as the return to date is estimated at <1% based on 94-09 mean run timing.

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.

The total Nisga’a harvest estimate of Nass coho to date is 28. FSC catches to week ending 17 July are average for coho (8 vs. 9 mean) based on mean catch monitoring results from 2000 to 2009. Nisga’a FSC harvest of coho is anticipated to reach between 2,000 and 4,000 in 2010.

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 ~83,000.

NASS PINK SALMON:

Total catch of pink salmon at the Nass fishwheels to date is 34. The GW catch (14 vs. 76 mean) of pink is below average based on mean catches for even years from 1994-2009 to week ending 17 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 1,368. FSC catches to week ending 10 July are just below average for pink (41 vs. 53 mean) based on mean catch monitoring results from 2000 to 2009 for even year catches.

Area 3 commercial net fishery harvests of pink salmon to date is 30,019 (126 released). The total in-season harvest estimate of pink salmon in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~430,000.

NASS CHUM SALMON:

Total catch of chum salmon at the Nass fishwheels to date is 4. The GW catch (2 vs. 2 mean) of chum is average based on mean catches from 1994-2009 to week ending 17 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 30. FSC catches to week ending 10 July are below average for chum (30 vs. 100) based on mean catch monitoring results from 2000 to 2009 catches.

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 ~500,000.

OTHER FISHWHEEL CAUGHT SPECIES:

Other catches of salmon and non-salmon species at the fishwheels to date include: 151 Pacific lamprey, 93 whitefish, 69 cutthroat, 50 Dolly Varden, 44 Northern pike minnow, 36 rainbows, 17 suckers, 4 spiny sculpins, and 2 long-fin smelt.

Escapement updates will be available at the above website link on Tuesday, 20 July and Thursday, 22 July.

The next Nass River public stock assessment update from Nisga’a Fisheries is planned for: Sunday, 25 July.