Attached is a stock assessment summary update for the nass river (pdf format) from the nisga'a fisheries and wildlife department of nisga'a lisims government.  Sayt-k'il'im-goot.

All data presented in this update are preliminary and subject to change with further assessment information that becomes available and should be interpretated cautiously for in-season assessment purposes only.

Archived updates and announcements from nisga'a fisheries and wildlife department are available at the following link:

ftp://ftp.Lgl.Com/pub//nass_stock_assessment_updates

nass fishwheel operational notes:

fishwheel assessment data up to sunday 20 july 2008.


Gw fishwheels (test fishery - 15th year):  fishwheels 1 and 2 were started on 5 june for tagging and historical catch index assessments for salmon and steelhead.  Fishwheels 1 and 2 are operating well at average water level for date.  Average water level from 1992 to 2007 was 2.6 M for date.  All fish that have been caught in the gitwinksihlkw fishwheels have been released.

Grease harbour fishwheels:  three fishwheels will operate at grease harbour in 2008 for in-season mark recapture tag recoveries.  The fishwheel startup dates were: 11 june (fw5), 12 june (fw6) and 13 june (fw3).  All three fishwheels are operational.  All fish caught in the grease harbour fishwheels have been released.

Since only three fishwheels are fishing at grease harbour compared to four since 2000, total fishwheel catches in 2008 as reported below will not be directly comparable with fishwheel catch averages from 2000 to 2007.  Catch average comparisons at the gw fishwheels will be comparable and are provided once a week as week ending comparisons on mondays in the attachment.

Nass sockeye salmon:
the nass sockeye run size estimate to gitwinksihlkw to date (147,298) is currently tracking just above average (143,000) return based on a mean run size to gitwinksihlkw of 281,000 from 1994 to 2007.  This estimate is a combination of mark-recapture and historical catch indices methods.  Note that mark recapture estimates will change over a 5 day period due to mark rates stabilizing at grease harbour as fish tagged at gw are passing the gh fishwheel sites over a 5 day period. After the mark rate stabilizes, the daily estimate is better at predicting actual catch efficiencies at the gw fishwheels than the historical indices. As such we will use historical catch efficiencies during the 5 d fluctuating period while mark recapture estimates are stabilizing for less fluctuating estimates that are reported.  Currently, mark recapture estimates are final to 15 july and later dates will fluctuate from 16 july to 25 july as additional catch and tag recovery data become available from the gh fishwheels.

The run size target for nass sockeye to gitwinksihlkw is 225,000 to 250,000 depending on harvests projected above gitwinksihlkw.  Nisga'a fisheries is estimating that approximately 47% (93-07 median) of the sockeye run has passed gitwinksihlkw to date.  Using final mark-recapture estimates to 15 july, current forecast methods are predicting a good probability of reaching the run size target to gw (225,000) with estimates ranging from 292,000 (mean run timing method - range 255,000-329,000) to 295,000 (in-season to final method).

The net escapement estimate for nass sockeye to date is 141,205.  The net escapement target is 200,000 (160,000 to meziadin river and 40,000 to non-meziadin systems).

Meziadin fishway opened on 1 july for escapement counts to river.  Total counts of sockeye at meziadin to 20 july are:  56,187 adults (1596 tags) and 48 jacks.  The 2008 cumulative adult count (56,187) to date is above average (41,000) based on mean counts at the meziadin fishway from 1994 to 2007.  The average count of adult sockeye from 1994 to 2007 was 170,000.  The preliminary fishwheel mean-run timing forecast is predicting ~184,000 (range: 136,000-238,000) to reach the fishway based on current escapement passed gw and average stock proportion.  Nisga'a fisheries is estimating that ~23% of the meziadin sockeye run has reached the fishway to date based on mean counts from 1990 to 2007.

Nisga'a fisheries is currently using a preliminary total return to canada (trtc) estimate for nass sockeye of between 350,000 (pre-season) and 429,000 (in-season) for tracking the nisga'a entitlement of nass sockeye that is currently ranging between 52,000 and 70,000.  The 2008 trtc estimates are forecasting below average (666,000) based on trtc returns from 1994 to 2007.  Trtc returns will be influenced by alaskan catches which are below average to date (see below).

The total nisga'a catch estimate of nass sockeye to date is 23,094. This total includes fsc catch (13,988) to week ending 12 july and individual marine sale fishery catch estimates to date (9106).  The total average nisga'a fsc harvest for the same week ending period of nass sockeye from 2000 to 2007 was 13,500.  The annual total average nisga'a fsc harvest from 2000 to 2007 of nass sockeye was 26,000.   The next nisga'a catch estimate for week ending 19 july will be updated on wednesday, 23 july.

Nisga'a food fish (fsc) harvesting is open for all species and is anticipated to reach between 25,000 and 35,000 sockeye in 2008.  Given that total fsc amounts are not expected to exceed the total nisga'a entitlement estimate for 2008, the remaining entitlement (~30,000 to 40,000) will be available for sale fisheries.  Therefore the director of nisga'a fisheries and wildlife has opened the nisga'a marine individual sale fishery for harvesting nass sockeye as a sale fishery.   In-river sale fisheries are closed to date.   No harvesting from the fishwheels will occur in 2008.   All fish are being released from the fishwheels.

Two nisga'a individual sale fisheries have occurred to date (16-17 july; 17-18 july) in area 3-12 with 17 boats participating.  Total catches in the nisga'a marine fisheries to date are:   9106 sockeye, 491 pink, 118 coho and 79 chum.

Nisga'a fisheries has announced the next marine fishery:  48 hr nisga'a marine fishery in area 3-12 for wednesday 23 july (6 pm) to friday 25 july (6 pm).

The nisga'a nation passed a resolution at the special assembly in may 2008 recommending the closure of the general commercial fishing in area 3-12 due to pre-season conservation concerns of nass sockeye and chinook.  Dfo kept area 3-12 closed to 20 july due to the poor return of chinook and ensuring good escapement of nass sockeye into the river.  Dfo have now opened area 3-12 to the general commercial fishery with the majority of nass chinook through the marine waters and the nass sockeye run currently on track to reach the escapement goal.

Area 3 is opened today to both seines and gillnets.  This opening coincides with openings in areas 4, 5 and 6 that are expected to split the fleet of 300 gillnetters that have fished to date.  Area details can be obtained from the dfo announcement on their website.   Fisheries conducted to 20 july in area 3 have been five gillnet [24 june (170 boats), 1 july (209 boats), 7 july (174 boats), 14 july (179 boats) and 15 july (5 boats)] and two seine (14 july (13 boats) and 15 july (5 boats)) fisheries.  Total commercial harvest estimates in area 3 to 20 july are: 29,744 sockeye, 5805 pink, 11,488 chum and 391 chinook (source of data is from dfo prince rupert fisheries management).

Alaska gillnet fisheries in districts 101 (tree point) and 106 (sumner and upper clarence) began on 15 june and 8 june, respectively. Alaskan seine fisheries in districts 101 to 104 typically start in alaskan week's 25 (15-21 june; district 102), week 27 (29 june - 5 july; districts 101 and 104) and week 29 (13-19 july; district 103). Seine fisheries opening dates to date are: districts 101 (lower clarence/revilla; opened on 6 july), 102 (middle clarence; opened on 22 june), 103 (cordova; not open yet) and 104 (noyes/dall; opened on 6 july).

Total in-season catch estimate of sockeye in southeast alaskan fisheries is 52,098 based on data to 20 july on the adfg website and is complete catch reporting for week 29 (ended 19 july). Reported catches are below average to date.  Average catch of sockeye in southeast alaskan fisheries is 714,000 sockeye from 1999 to 2007. Of the total alaskan catch of sockeye, nisga'a fisheries is estimating approximately 21,000 are nass sockeye based on average stock % data (1982-98) and is below average to date. Average catch of nass sockeye is 165,000 from 1999 to 2007.

Nass chinook salmon:
the nass chinook run size estimate to gitwinksihlkw (13,423) is tracking below average to date (21,000) based on a mean run size to gitwinksihlkw of 22,000 from 1994 to 2007.  The run size target for nass chinook to gitwinksihlkw is 17,000 depending on harvests projected above gitwinksihlkw.  The in-season tracking of the nass chinook run to gitwinksihlkw is predicting between 14,000 and 15,000 [mean run timing method [range 14,000-15,000] and in-season to final method] as the final in-season run size total to gitwinksihlkw.  The 2008 return to date is the third worst on record since the start of the nisga'a fisheries program in 1992.  Nisga'a fisheries is estimating that 96% (93-07 median) of the run has passed gitwinksihlkw to date. The net escapement estimate for nass chinook is 12,394.  The net escapement target for nass chinook above grease harbour is 15,000.

Total counts of chinook at meziadin fishway to date are: 159 adults (2 tags) and 6 jacks.  The 2008 cumulative adult count (159) to date is above average (61) based on mean counts at the meziadin fishway from 1994 to 2007.  The average count of adult chinook at meziadin fishway from 1994 to 2007 was 480. The preliminary fishwheel mean-run timing forecast is predicting 320 chinook (range: 70-710) to reach the fishway based on current escapement passed gw and estimated stock composition.  Nisga'a fisheries is estimating that ~12% of the meziadin chinook run has passed the fishway to date based on mean counts from 1990 to 2007.   Mark-recapture surveys for final escapement estimates are also planned at kwinageese and damdochax rivers in september 2008.

The kincolith video-counting fence began operation on 11 june for collecting escapement data for the kincolith river and providing an index of escapement to coastal streams in area 3.  Net upstream counts at the weir to 20 july are:  676 chinook (133 afc and 22 broodstock) and 1 pink.  Other weir counts to date are: 15 steelhead (7 down and 8 up).  The current count of chinook passing the weir is above the average count (493) for the date from past operations (2001, 2002, 2005-2007).  Nisga'a fisheries is projecting to date that the escapement forecast (~1,800 - range 800-2700) for kincolith chinook is currently on target of making the escapement goal (700) based on mean run timing from past operations (2001, 2002, 2005-2007) but the forecast is imprecise at this date.  Nisga'a fisheries is estimating that ~38% of the kincolith chinook run has passed the weir to date based on the reconstructed mean run timing.

Nisga'a fisheries is using a preliminary trtc estimate for nass chinook of between 20,000 (in-season) and 21,000 (pre-season) for tracking the nisga'a entitlement of nass chinook.  The 2008 trtc estimates are forecasting below average (36,000) based on trtc returns from 1994 to 2007.  Uncertainty of marine commercial and recreational catches of nass chinook make it difficult to accurately estimate in-season trtc estimates for nass chinook. However, based on the in-season trtc estimates for 2008, the nisga'a entitlement of nass chinook is ~4,000.  A cumulative underage of 3300 from past year's management uncertainty may be needed to fulfill nisga'a fsc needs in 2008 which on average total 6200 nass chinook.  As a result of fsc requirements, the entitlement target is expected to range between 4000 and 7300 depending on in-season run size estimates during the season.

The nisga'a catch estimate of nass chinook to week ending 12 july is 3649 and below average (00-07) for the period.  The total average nisga'a fsc harvest of nass chinook from 2000 to 2007 for the same week ending period was 5500.  The annual total average nisga'a fsc harvest of nass chinook from 2000 to 2007 was 6200.  The next nisga'a catch estimate for week ending 19 july will be updated on wednesday, 23 july.   No chinook are permitted for sale in any individual sale fisheries in 2008.

Nass coho salmon:
the fishwheel catch of coho (26) to date is above the mean catch (20) from 2000-2007. At this early stage, the nass coho run size estimate to gitwinksihlkw (458) is tracking above average to date (130) based on a mean run size to gitwinksihlkw of 76,000 from 1994 to 2007.  The run size target for nass coho to gitwinksihlkw is 50,000 depending on harvests projected above gitwinksihlkw.

Total counts of coho at meziadin fishway to date are: 0 adults (0 tags) and 0 jacks. The 2008 cumulative adult count (0) to date is the same as the average (0) based on mean counts at the meziadin fishway from 1994 to 2007.  The average count of adult coho at meziadin fishway from 1994 to 2007 was 3600. Coho begin passing the fishway in early august.

Nisga'a fisheries is currently using the pre-season trtc estimate for nass coho of 104,000 for tracking the nisga'a entitlement (8,000) of nass coho.  The 2008 trtc estimate is forecasted for a below average (162,000) return based on trtc returns from 1994 to 2007.

The total nisga'a catch estimate of nass coho to date is 121. This total includes fsc catch (3) to week ending 12 july and individual marine sale fishery catch estimate to date (118).  The next nisga'a fsc catch estimate for week ending 19 july will be updated on wednesday, 23 july.

Nass pink salmon:
the fishwheel catch of pink salmon (53) to date is below the mean catch (200) for even year returns from 2000 to 2007.

Nisga'a fisheries is currently using the pre-season trtc estimate for nass pinks of 569,000 for tracking the nisga'a entitlement (54,000) of nass pink. The 2008 trtc estimate is forecasting above average (524,000) based on trtc returns of even year pinks from 1994 to 2007. However, the last nass pink salmon even return year (2006) was extremely low (230,000).

The total nisga'a catch estimate of nass pink to date is 548. This total includes fsc catch (57) to week ending 12 july and individual marine sale fishery catch estimate to date (491). The next nisga'a catch estimate for week ending 19 july will be updated on wednesday, 23 july.

Nass chum salmon:
the fishwheel catch of chum (6) to date is just above the mean catch (4) from 2000-2007.

Nisga'a fisheries is currently using the pre-season trtc estimate for nass chum of 90,000 for tracking the nisga'a entitlement (7,000) of nass chum.  The 2008 trtc estimate is forecasting an average (91,000) return based on trtc returns from 1994 to 2007.

The total nisga'a catch estimate of nass chum to date is 120.  The total includes fsc catch (41) to week ending 12 july and individual marine sale fishery catch estimate to date (79). The next nisga'a catch estimate for week ending 19 july will be updated on wednesday, 23 july.

Nass summer-run steelhead:
the fishwheel catch of steelhead (8) to date is just below average catch level (9) from 2000-2007.

Total counts of steelhead at meziadin fishway to date are: 0 adults (0 tags). The 2008 cumulative adult count (0) to date is the same as the average (0) based on mean counts at the meziadin fishway from 1994 to 2007. The average count of steelhead during operation of meziadin fishway from 1994 to 2007 was 50. Steelhead begin passing the fishway in late august.

The nisga'a catch estimate of nass steelhead to week ending 12 july is 29. The next nisga'a catch estimate for week ending 19 july will be updated on wednesday, 23 july.

Next nass stock assessment update - wednesday 23 july 2008

Richard Alexander, RPBIO
Nisga'a Fisheries Stock Assessment Management Biologist
Nisga'a Lisims Government - Fisheries & Wildlife Department
P.O. Box 228, New Aiyansh, BC, V0J 1A0
phone:  (250) 633-2617
fax:        (250) 633-2971