Nass Update to July 2

Here is the Nass Update to July 2. Information supplied courtesy of the Nisga'a Fisheries Department.


2010 NASS RIVER STOCK ASSESSMENT UPDATE – 2 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 (AND MEZIADIN FISHWAY) OPERATIONAL NOTES:

Fishwheel (and Meziadin Fishway) assessment data: Up to Thursday 1 July 2010

Meziadin Fishway began on 29 June and counts to date are: 2 adult sockeye.

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.

Fishwheels 1 and 2 are currently operating at very low water levels to date (1.6 m vs. 3.0 m average (94-09)).

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.

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).

No harvesting has occurred at the GH fishwheels to date other than a small sample of Chinook (69) being sacrificed for morphometric research as part of the Nass Chinook Sentinel Stock Program. These fish have been distributed to the elders and community food programs. Daily catches of salmon at the Grease Harbour fishwheels have been relatively small for sockeye (averaging 40 per day) and Chinook (averaging 30 per day) over the past five days.
NASS SUMMER-RUN STEELHEAD:

Total catch of steelhead at the Nass fishwheels to date is 16 adults. The GW catch (11) of adult steelhead is currently above average (5) based on mean catches from 1994-2009.
In-season run size estimates that will be 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. These estimates will begin in mid-July.
The Nisga’a catch of steelhead to week ending 26 June is 300 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.
NASS SOCKEYE SALMON:

Total catch of sockeye at the Nass fishwheels to date is 2,745 adults (1,677 tagged) and 467 jacks. The GW catch (2,024) of adult sockeye is currently below average based on mean catches from 1994-2009. The mean 94-09 cumulative catch of adult sockeye at GW fishwheels to week ending Saturday 3 July will be 4,300.

The Nass sockeye in-season run size estimate to Gitwinksihlkw to 1 July (62,101) is currently tracking at an average level (64,000) 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 27 June. 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 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 in-season net escapement estimate for Nass sockeye to date is ~61,600. The net escapement target is ~200,000.

Nisga’a Fisheries estimates that ~23% of the Nass sockeye run has reached Gitwinksihlkw to date based on mean run timing from 1993 to 2009. The current in-season run size estimate compared to a regression of in-season to post-season estimates from 1993-2009 is currently projecting a post-season run size estimate to Gitwinksihlkw of 286,000 (r2=0.35; 95%CI: 60,000, 514,000). It is still too early to make any in-season forecasts of the projected Total Return to Canada (TRTC) estimate for Nass sockeye. Pre-season TRTC forecasts range between 350,000 (minimum brood estimate) and 686,000 (maximum brood estimate).

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 sibling (age) TRTC pre-season method (648,000) has tracked well in the past and will be used by Nisga’a Fisheries for calculating the initial target for the in-season Nisga’a allocation (113,000). This target will be adjusted accordingly based on in-season data. The actual allocation target may be up to 2,000 less to account for a cumulative overage accrued from 2000 to 2009.

Nisga’a food fish (FSC) harvesting is open for all salmon species and is anticipated to reach between 25,000 and 40,000 Nass sockeye in 2010. The total Nisga’a harvest estimate of Nass sockeye to week ending 26 June is 2,398. FSC catches to week ending 26 June are currently below average for sockeye (2,398 vs. 4,200) based on historical catch monitoring results from 2000 to 2009. The next Nisga’a salmon catch estimate for week ending 3 July will be available on Wednesday, 7 July.

A 12-hr opening (6:00 to 18:00 hrs) Nisga’a marine sale fishery in Area 3 is occurring today (Friday 2 July). Preliminary reports of today’s fishery are 29 boats participating with mean catches of 24 sockeye per boat. Nisga’a in-river sale fisheries are not expected to begin until the second week of July. Public announcements by the Nisga’a Fisheries and Wildlife Department will be made 48 hours prior to any fishery being opened.

Area 3 commercial fisheries conducted in 2010 to date: 4 gillnet [15 June (150 boats), 21 June (164 boats), 28 June (216 boats) and 29 June (216 boats)]. Total in-season commercial harvest estimates in Area 3 to date are: 30,919 sockeye, 0 coho, 265 pink, 3,111 chum and 582 Chinook. Area 3 commercial gillnet releases of salmon are: 1,389 coho, 19 pink, 589 chum, 178 Chinook and 122 steelhead. The next Area 3 gillnet fishery has been announced by DFO for Monday 5 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. District 102 (Middle Clarence) Alaskan seine fishery began on 21 June. Total catches at Tree Point to date are approximately: 29,000 sockeye, 1,080 Chinook, 2,800 coho, 10,150 pink and 64,000 chum salmon. Total catches in the District 106 gillnet fishery to date are approximately: 17,000 sockeye, 415 Chinook, 36,200 coho, 1,800 pink and 5,600 chum salmon. Source of Alaskan commercial information is from the Alaskan Department of Fish and Game (ADFG) website.

NASS CHINOOK SALMON:

Total catch of Chinook at the Nass fishwheels to date is 809 adults (300 tagged) and 229 jacks. The GW catch (275) of adult Chinook is currently below average based on mean catches from 1994-2009. The mean 94-09 cumulative catch of adult Chinook at GW fishwheels to week ending Saturday 3 July will be 1,300.

The Nass Chinook in-season run size estimate to Gitwinksihlkw to 1 July (7,011) is currently tracking below average (13,500) 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 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 recommended in-season run size target for adult Nass Chinook to Gitwinksihlkw in 2010 is 18,000 depending on harvests projected above GW. The net escapement estimate for Nass Chinook to date is ~6,033. The net escapement target is ~15,000.

Nisga’a Fisheries estimates that ~58% of the Nass Chinook run has reached Gitwinksihlkw to date based on mean run timing from 1994 to 2009. The current in-season run size estimate compared to a regression of in-season to post-season estimates from 1994-2009 is currently projecting a post-season run size estimate to Gitwinksihlkw of 18,500 (r2=0.41; 95%CI: 8,200, 29,000).

It is still too early to make any in-season forecasts of the projected TRTC estimate for Nass Chinook. Pre-season TRTC forecasts range between 29,000 (minimum brood estimate) and 44,000 (maximum brood estimate). Based on the TRTC forecasts and the minimum escapement goal (10,000), the Nisga’a allocation of Nass Chinook ranges between 6,000 and 9,500. The sibling (age) TRTC estimate (33,000) continues to be used for calculating the initial target for the in-season Nisga’a allocation (7,000) of Nass Chinook. This target will be adjusted during the season based on in-season date. The actual allocation target could be up to 4,500 more to account for management uncertainty allowances as part of the overage/underage calculations from 2000 to 2009. However, based on in-season data to date indicating a smaller return than expected, the underage will not be targeted in 2010.

The total Nisga’a harvest estimate of Nass Chinook to week ending 26 June is 2,900. FSC catches to week ending 26 June are currently above average for Chinook (2,900 vs. 2,361) based on historical catch monitoring results from 2000 to 2009. Nisga’a FSC harvest of Chinook is anticipated to reach between 6,000 and 9,000 in 2010.

Area 3 commercial gillnet harvest of Chinook to date is 582 (178 released). No estimates of the Nass component are currently available to Nisga’a Fisheries. The total in-season harvest estimate of Chinook in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is 1,495.

NASS COHO SALMON:

No coho salmon have been caught at the Nass fishwheels or in the Nisga’a fishery to date. Coho typically begin to be caught at the fishwheels in mid-July.

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.

A total of 1,389 coho were released in the Area 3 commercial gillnet fishery to date. The total in-season harvest estimate of coho in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is 39,000 to date.

NASS PINK SALMON:

No pink salmon have been caught at the Nass fishwheels or in the Nisga’a fishery. Pink salmon typically begin to be caught at the fishwheels in the first week of July.

Pre-season TRTC forecasts for Nass pinks range between 68,000 (minimum brood estimate) and 230,000 (maximum brood estimate) for two year, even 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. The mean brood pre-season TRTC estimate (149,000) will be used for calculating the initial target for the in-season Nisga’a allocation (<500). This target will be adjusted during the season based on in-season data. No cumulated overages or underages exist from 2000 to 2009.

A total of 265 pink salmon were harvested (19 released) in the Area 3 commercial gillnet fishery to date. The total in-season harvest estimate of pink salmon in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is 11,950 to date.

NASS CHUM SALMON:

Two chum salmon has been caught at the Nass fishwheels to date. Chum salmon typically begin to be caught at the fishwheels in the second week of July. No chum have been caught in the Nisga’a fishery to date.

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 mean brood pre-season TRTC estimate (61,000) will be used for calculating the initial target for the in-season Nisga’a allocation (5,000). This target will be adjusted during the season based on in-season data. The actual allocation target may be up to 36,000 more to account for overage/underage allowances from 2000 to 2009. However, underages would only be targeted in productive return years as assessed during the season, and opportunities of utilizing the underage for Nass Area chum are not anticipated for 2010.

A total of 3,111 chum salmon (589 released) were harvested in the Area 3 commercial gillnet fishery to date. The total in-season harvest estimate of chum salmon in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is 69,600 to date.

The next Nass River public stock assessment update is planned for: Sunday, 11 July.

Escapement updates will be available at the above website link on Tuesday, 6 July and Thursday, 8 July.