Nass Update #1, 2010

Here is the first Nass Update for 2010. Information courtesy of Nisga'a Fisheries.
We have moved the steelhead stection to the top for quicker reference.

2010 NASS RIVER STOCK ASSESSMENT UPDATE

Attached is the first public Nass River salmon stock assessment 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.

The email send out list is from last year with some updates but if you would like to be removed or others added, please email for changes.

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:

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

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

NASS FISHWHEEL (AND MEZIADIN FISHWAY) OPERATIONAL NOTES:

Fishwheel assessment data: Up to Saturday 19 June 2010
Meziadin Fishway: Begins operation on approximately 1 July 2010

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. Fishwheels 1 and 2 are currently operating at below average water levels to date (2.2 m vs. 3.4 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 (with the exception of a small sample of adult Chinook (~150) being sacrificed for scientific research as part of the Nass Chinook Sentinel Stock Program).

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).

NASS SUMMER-RUN STEELHEAD:

Total catch of steelhead at the Nass fishwheels to date is 15 adults. The GW catch (10) 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 12 June is 248 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 monitoring programs.

NASS SOCKEYE SALMON:

Total catch of sockeye at the Nass fishwheels to date is 220 adults and 11 jacks. The GW catch (155) of adult sockeye is below average (470) based on mean catches from 1994-2009.

The Nass sockeye in-season run size estimate to Gitwinksihlkw to 19 June (5,090) is currently tracking below average (10,000) based on a mean run size to Gitwinksihlkw of 278,000 from 1994 to 2009. The in-season net escapement estimate for Nass sockeye to date is 5,065. The net escapement target is ~200,000.

The in-season run size estimate is calculated by either a mark-recapture or historical catch indices method. Currently, the run size is estimated based on catch indices where the cumulative daily catch of sockeye at FW1 and FW2 is multiplied by weekly historic catchability expansion factors from 1994-2009 results. This method is the historical catchability index method which will be used until mark-recapture estimates begin later in June when enough tag recaptures have been caught at the GH fishwheels to begin making reliable mark-recapture estimates. A spreadsheet of the calculations and range of in-season estimates under different fishwheel water level conditions 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.

It is too early to make any in-season forecasts of projected run size to GW or Total Return to Canada (TRTC) estimates 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 ranges between 52,000 and 118,000 sockeye. 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 the cumulative overages/underages 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 for Nass sockeye in 2010. The total Nisga’a harvest estimate of Nass sockeye to week ending 12 June is 77. The current FSC catch (77) is below average (2,000) for the 12 June week ending period based on 1994-2009 catches. The next Nisga’a salmon catch estimate for week ending 19 June will be available on Wednesday, 23 June.

No Nisga’a marine or in-river individual sale fisheries for Nass sockeye have occurred to date; or have been announced by the Nisga’a Fisheries & Wildlife Department to date. A public announcement by Nisga’a Fisheries will be made early next week regarding plans for the first Nisga’a marine sale fishery. In-river sale fisheries are not expected to begin until early July.

Area 3 commercial fisheries conducted in 2010 to date has been 1 gillnet [15 June (150 boats)]. Total in-season commercial harvest estimates in Area 3 to date are: 3512 sockeye, 0 coho, 0 pink, 43 chum and 199 Chinook. Area 3 commercial gillnet releases of salmon are: 55 coho, 25 chum and 48 Chinook. The next Area 3 gillnet fishery has been announced by DFO for Monday 21 June. 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) will begin on 20 June and 21 June, respectively. District 102 (Middle Clarence) Alaskan seine fishery opens on 21 June. 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 200 adults and 27 jacks. The GW catch (67) of adult Chinook is below average (260) based on mean catches from 1994-2009.

The Nass Chinook in-season run size estimate to Gitwinksihlkw to 19 June (1,690) is currently tracking below average (3,000) based on a mean run size to Gitwinksihlkw of 23,000 from 1994 to 2009. The recommended in-season run size target for adult Nass Chinook to Gitwinksihlkw in 2010 is 18,000. The net escapement estimate for Nass Chinook to date is 1,296. The net escapement target is ~15,000.

The in-season run size estimate is calculated by a historical catch indices method where the cumulative daily catch of Chinook at FW1 and FW2 is multiplied by a range of annual historic catchability expansion factors from 1994-2009 results. A spreadsheet of the calculations and range of estimates under different fishwheel water level conditions is provided in the attachment.

It is too early to make any in-season forecasts of projected run size to GW or TRTC estimates 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) will 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 may be up to 4,500 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 Chinook to week ending 12 June is 1079. The current FSC catch (1079) is below average (1,670) for the 12 June week ending period based on 1994-2009 catches. 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 199 (48 released). No estimates of the Nass component are currently available to Nisga’a Fisheries.

Total in-season harvest estimates of Chinook in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 are 0 with Districts 101 (GN), 102 (SN) and 106 (GN) opening on 20 June or 21 June.

NASS COHO SALMON:

No coho salmon have been caught at the Nass fishwheels or in the Nisga’a fishery to date. A total of 55 coho were released in the Area 3 gillnet fishery on 15 June.

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.

NASS PINK SALMON:

No pink salmon have been caught at the Nass fishwheels, in the Nisga’a fishery, or in Area 3 commercial fisheries to date.

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.

NASS CHUM SALMON:

No chum salmon have been caught at the Nass fishwheels or in the Nisga’a fishery to date. A total of 43 chum (25 released) were harvested in the Area 3 gillnet fishery on 15 June.

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.

The next Nass River public stock assessment update is planned for: Friday, 25 June.

An escapement update will also be available at the above website link on Tuesday, 22 June and Thursday, 24 June.

Richard Alexander, R.P.Bio
Nisga’a Fisheries Stock Assessment Management Biologist
Nisga’a Lisims Government - Fisheries & Wildlife Department
PO Box 228, New Aiyansh, BC, V0J 1A0
Phone: (250) 633-2617
Fax: (250) 633-2971
Cell: (250) 857-5129
Nisga’a Fisheries (website: http://www.nisgaalisims.ca/?q=fisheries-and-wildlife )
LGL Limited (website: http://www.lgl.com )