Nass Update to August 28th

Here is the latest Nass Update to Friday August 28th. Information provided courtesy of Nisga'a Fisheries.
Of note:
-Nass steelhead run estimate above average at 9,646 versus 5,500 (94-08 mean return)
-Nass sockeye escapement goal reached
-Coho well above average estimated at 152,916 versus the 94-08 mean of 51,000
-Pinks above average
-Chum below average with Area 3 gillnet bycatch harvest of 46,427 with another 26,252 'released'....with a high associated mortality.



2009 NASS RIVER STOCK ASSESSMENT UPDATE

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 – 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/

(Note: 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, 27 August 2009.

GITWINKSIHLKW (GW) FISHWHEELS (TEST FISHERY - 16TH YEAR): Fishwheels 1 and 2 were started on 1 June for tagging and historical catch index assessments for salmon and steelhead. The fishwheels were shutdown during the high water period (2-15 June) and re-started on 16 June. Fishwheels 1 and 2 are currently operating well at below average water levels to date (1.3 m vs. 1.8 m average (94-08)). All fish caught in the Gitwinksihlkw fishwheels have been released.

GREASE HARBOUR (GH) FISHWHEELS (~17 KM UPSTREAM OF TEST FISHERY): Up to four fishwheels were operated at Grease Harbour (upstream of Ts'im Anwiihlist) in 2009 for in-season mark-recapture tag recoveries and some selective harvesting of sockeye, Chinook and coho based on Nisga’a entitlement levels and targets as directed by Nisga’a Lisims Government. The GH fishwheel start-up dates were: 17 June (FW6), 23 June (FW3), 25 June (FW5) and 7 July (FW4). All four fishwheels are currently operational.

NASS SUMMER-RUN STEELHEAD:

In-season run-size estimates or other information 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.

The total fishwheel catch of Nass steelhead (1,006) to 27 August is above average (600) based on fishwheel operations from 2000 to 2008. Specifically, steelhead catches (226) at the Gitwinksihlkw fishwheels to week ending, 22 August, are above average (132) for the same week ending period.

The run size estimate of Nass summer-run steelhead to Gitwinksihlkw to 27 August is 9,646 with ~62% (94-08 median) of the run estimated to have passed Gitwinksihlkw to date. The in-season run size estimate is currently tracking above average (5,500) based on mean returns from 1994 to 2008. During typical Gitwinksihlkw fishwheel operation (July to early to mid September), the preliminary minimum run size target for Nass summer-run steelhead to Gitwinksihlkw is ~4,200 (depending on any losses projected above Gitwinksihlkw) and has been reached in 2009 based on in-season data. The mean run size estimate to Gitwinksihlkw from 1994 to 2008 is ~10,100 (includes the adjustment in the difference between the fishwheel catch index and steelhead mark-recapture methods).

Note that there is some uncertainty in the in-season run size estimate for Nass steelhead due to a different tag type being applied to coho than in the past and the uncertainty associated with the coho mark rate that is being used for generating the steelhead estimate. However, the current estimate is within the range of the other estimates generated from historical catch index methods (i.e., 5,500 (high catchability) to 11,000 (low catchability)). A spreadsheet of the calculations and the range of estimates is provided in the attachment.

The run size estimate for summer-run steelhead is a combination of mark-recapture and historical catch index methods at GW fishwheels. 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. Steelhead run size estimates will change over a 7 day period due to coho mark rates stabilizing at Grease Harbour as tagged fish at Gitwinksihlkw pass the upstream Grease Harbour fishwheel sites over a 7 day period.

The net run size estimate above Grease Harbour for Nass summer-run steelhead is 9,536. The minimum net run size target for Nass summer-run steelhead above Grease Harbour is ~4,000 during typical operations of the Gitwinksihlkw fishwheels from July to first or second week of September and was reached for 2009 based on in-season data.

Total counts of steelhead at Meziadin Fishway to date are: 1 adult (0 adipose marks). The 2009 cumulative adult count to date is above the average (0) based on mean counts at the Meziadin Fishway from 1994 to 2008. The average count of steelhead during operation of Meziadin Fishway (July to mid-October) from 1994 to 2008 is 30. Steelhead begin passing the Fishway in late August.

The Nisga’a harvest estimate of Nass steelhead to week ending 22 August is 226. The average harvest of Nass summer-run steelhead in Nisga’a Fisheries is ~400 from 1994 to 2008. A total of 97 steelhead were also released alive during all Nisga’a fisheries (i.e., FSC, marine and in-river sale fisheries).


NASS SOCKEYE SALMON:

The Nass sockeye run size estimate to Gitwinksihlkw to 27 August (257,403) is currently tracking below average (270,000) based on a mean run size to Gitwinksihlkw of 278,000 from 1994 to 2008.

The run size estimate is a combination of mark-recapture and historical catch indices methods. Currently, mark-recapture estimates are final to 22 August and later dates will fluctuate as additional catch and tag recovery data become available from 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 depending on harvests projected above Gitwinksihlkw. Although the net escapement goal (200,000) for Nass sockeye has been achieved at lower in-season aggregate run size targets (225,000 to 250,000) in seven of the past nine years since the implementation of the Nisga’a treaty, the Meziadin goal (160,000) has only been achieved in two years of the past nine years. Therefore, Nisga’a Fisheries recommended to DFO (and DFO agreed) that the run size target should be increased to 275,000 in 2009 to have a greater certainty of reaching the Meziadin River escapement goal which has represented between 51% and 85% (avg. is 68%) of the total Nass sockeye aggregate population since 1994.

Using final mark-recapture estimates to 22 August, preliminary forecast methods are currently predicting to be under the run size target (275,000) to Gitwinksihlkw for 2009 with forecast estimates at approximately 265,000 Although the aggregate in-season sockeye run size target to GW may not be reached in 2009, the net escapement goal has been reached based on in-season data.

The net escapement estimate for Nass sockeye to date is 222,495 with 34,908 sockeye estimated to have been harvested above GW. The current net escapement target is ~200,000 (160,000 to Meziadin River and ~40,000 to non-Meziadin systems). However, to reach the Meziadin escapement goal, the net escapement target typically will need to be larger than 200,000 (see comments below).

Meziadin Fishway opened on 1 July for escapement counts to the river. Total counts of sockeye at Meziadin to 27 August are: 147,510 adults (4,214 tags) and 10,804 jacks. The 2009 cumulative adult count to date is above average (136,000) based on mean counts at the Meziadin Fishway from 1994 to 2008. The fishwheel mean-run timing forecast is predicting ~152,000 sockeye (95% CI: 129,000, 175,000) to reach the Fishway based on current escapement passed GW, estimated mean stock composition (68%; 1994 to 2008) and projected harvests (40,000) above GW. This estimate will be higher if fewer than 40,000 sockeye are harvested above GW. In-season to final fishway count (180,000) and Meziadin mean count (181,000) methods are projecting higher forecasts to reach the fishway in 2009 based on current counts at the Fishway. The average count of adult sockeye from 1994 to 2008 is 169,000. Nisga’a Fisheries estimates that ~82% of the Meziadin sockeye run has reached the Fishway to date based on mean counts from 1990 to 2008.

The 2009 pre-season TRTC return (511,000) was expected to be below average (636,000) based on TRTC returns from 1994 to 2008. The in-season Nass sockeye projected TRTC is 405,000 (using 93-08 mean run timing – 97% (95% CI: 96%, 98%) with 95% CI of 400,000 and 410,000) and is below the pre-season TRTC estimate.

The Nisga'a entitlement of Nass sockeye ranges between 62,000 (in-season) and 86,000 (pre-season) depending on final post-season results.

Nisga’a food fish (FSC) harvesting continues to be open for all salmon species and is anticipated to reach between 25,000 and 30,000 for Nass sockeye in 2009. Given that the total in-season FSC amount was projected to not exceed the total Nisga’a entitlement estimate for 2009, the remaining entitlement was available for sale fisheries.

The total Nisga’a harvest estimate of Nass sockeye to date is 68,838. The total includes FSC catch (23,296) to week ending 22 August and sale fishery catch estimates to date (37,280 from individual sales and 8,262 from communal sales from GH fishwheels). The final Nisga’a catch estimate for week ending 29 August will be updated on Wednesday, 2 September.

Eight 12-hr Nisga’a marine individual sale fisheries occurred in 2009: 25 June (33 boats), 26 June (33 boats), 2 July (30 boats), 3 July (30 boats), 9 July (25 boats), 10 July (23 boats), 16 July (17 boats) and 17 July (17 boats) in Area 3-12. Total harvests in the Nisga’a marine sale fisheries in 2009 were: 16,373 sockeye; 20,891 pink; 240 Chinook and 30 coho.

Six 10-hr Nisga’a in-river individual sale fisheries occurred in 2009: 8 July, 15 July, 17 July, 19 July, 21 July and 23 July.

As a result of the downsizing of the TRTC and current entitlement amounts from in-season estimates, Nisga'a sale fisheries for sockeye are closed for 2009.

Area 3 commercial fisheries conducted in 2009 to date have been 10 gillnet [16 June (146 boats), 23 June (224 boats), 29 June (253 boats), 30 June (253), 6 July (264 boats), 7 July (229 boats), 13 July (258 boats), 4 July (224 boats), 20 July (164 boats) and 21 July (157 boats)] and 15 seine [13 July (19 boats),16 July (39 boats), 20 July (19 boats), 21 July (19 boats), 24 July (6 boats), 25 July (23 boats), 27 July (19 boats), 4 Aug (8 boats), 5 Aug (5 boats), 9 Aug (1 boat), 10 Aug (1 boat), 13 Aug (2 boats), 14 Aug (3 boats), 18 Aug (5 boats), and 19 Aug (4 boats)]. Total in-season commercial harvest estimates in Area 3 to date are: 104,530 sockeye, 1,020,083 pink, 46,427 chum, 1,933 coho and 1,296 Chinook (source of data is from DFO Prince Rupert Fisheries Management).

Alaskan gillnet fisheries in Districts 101 (Tree Point) and 106 (Sumner and Upper Clarence) began on 21 June and 15 June, respectively. Alaskan seine fisheries opening dates were: Districts 101 (Lower Clarence/Revilla; opened on 5 July), 102 (Middle Clarence; opened on 21 June), 103 (Cordova; 19 July) and 104 (Noyes/Dall; opened on 5 July). Alaskan fisheries continue in the above districts for both gillnet and seines.

Total in-season harvest estimates of sockeye in southeast Alaskan gillnet and seine fisheries in the above Districts is 376,223 based on data to week ending 34 (22 August) from the ADFG website. An attachment is provided showing the in-season breakout of catch by the respective district areas. The reported catches are below average (645,000) to the week ending period. The average total catch of sockeye in southeast Alaskan fisheries is 660,000 sockeye from 1999 to 2008. Of the Alaskan total catch of sockeye, Nisga’a Fisheries estimates that approximately 95,000 are Nass sockeye based on average stock % data (1982-07) and is below average (153,000) to week ending period. The average total catch of Nass sockeye in Alaskan fisheries is 156,000 from 1999 to 2008, and 185,000 in odd-years when targeting pinks.

NASS CHINOOK SALMON:

The Nass Chinook run size estimate to Gitwinksihlkw (23,743) is tracking above average (22,400) abundance levels to 27 August based on a mean run size to Gitwinksihlkw of 23,000 from 1994 to 2008. The run size target for Nass Chinook to Gitwinksihlkw is 17,000 depending on harvests projected above Gitwinksihlkw. The run size target for 2009 was reached based on in-season data.

The in-season tracking of the Nass Chinook run to Gitwinksihlkw predicts 24,000 as the final in-season run size total to Gitwinksihlkw using the two methods (in-season to final and mean run timing methods). Nisga’a Fisheries estimates that >99% (94-08 median) of the run has passed Gitwinksihlkw to date.

The net escapement estimate for Nass Chinook is 20,876 (harvests above GW to date are estimated at 2,867). The net escapement target for Nass Chinook above Grease Harbour is ~15,000 and was reached in 2009 based on in-season data.

Total counts of Chinook at Meziadin Fishway to 27 August are: 227 adults (6 tags) and 20 jacks. The 2009 cumulative adult count to date is currently below average (369) based on mean counts at the Meziadin Fishway from 1994 to 2008. The average count of adult Chinook at Meziadin Fishway from 1994 to 2008 is 480. The fishwheel mean-run timing forecast is predicting ~520 Chinook to reach the Fishway based on current escapement passed GW and estimated mean stock composition (2.6%; 1994 to 2008). In-season to final fishway count (330) and Meziadin mean count (292) methods are projecting lower forecasts to reach the fishway in 2009 based on current counts at the Fishway. Nisga’a Fisheries estimates that ~78% of the Meziadin Chinook run has passed the Fishway to date based on mean counts from 1994 to 2008.

Mark-recapture data for final escapement estimates for Upper Nass Chinook will be based primarily on Meziadin and Kwinageese weir counts and tag recovery information. Kwinageese weir operations began on 12 July. Total counts at the Kwinageese weir to 27 August are: 871 adult Chinook (23 tags) and 100 sockeye (no tags).

The Kincolith video-counting fence will not operate in 2009 due to water levels not cooperating for fully installing the weir after removing the log jam above the weir in the early summer months. The weir is beneficial to collecting escapement data for the Kincolith River and providing an index of escapement of salmon to coastal streams in Area 3. A mark-recapture study was conducted on Kincolith Chinook to estimate the number of Chinook that passed to the spawning areas in 2009. A total of 413 Chinook and 26 coho have been estimated to have been harvested from the Kincolith River to 17 August based on monitoring conducted by Nisga’a Fisheries

Nisga’a Fisheries is using a TRTC estimate for Nass Chinook of between 32,000 (in-season) and 48,000 (pre-season) for tracking the Nisga’a entitlement of Nass Chinook. The 2009 pre-season TRTC estimate was forecasting for an above average (36,000) return based on TRTC returns from 1994 to 2008; but in-season assessments are suggesting a below average return. 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 current TRTC estimate for 2009, the Nisga’a entitlement of Nass Chinook is between ~7,000 (in-season) and ~10,000 (pre-season). An additional allocation is also available as an underage (3,900) provision based on past year’s management uncertainty allowances; however, underages are only targeted in productive return years as assessed during the season.

The Nisga’a harvest estimate of Nass Chinook to date is 5,121. The total includes FSC catch (3,524) to week ending 22 August and sale fishery catch estimates to date (566 from individual sales and 1031 from communal sales from GH fishwheels).

Area 3 commercial gillnet harvest of Chinook to date is 1,296 (1759 released). No estimates of the Nass component are currently available to Nisga’a Fisheries.

Total in-season harvest estimate of Chinook in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is 11,721 based on data to week ending 34 (22 August) from the ADFG website. Reported catches are just below average (12,500) to date. The average total catch of Chinook in southeast Alaskan gillnets and seine fisheries in Districts 101 to 104 is ~13,000 Chinook from 1999 to 2008. No estimates of the Nass component are currently available to Nisga’a Fisheries.

NASS COHO SALMON:

The run size estimate of Nass coho to Gitwinksihlkw to 27 August is 152,916 with ~79% (94-08 median) of the run estimated to have passed Gitwinksihlkw to date.

A cautionary note to in-season coho run size estimates is that Nisga'a Fisheries is applying a different tag type (operculum versus spaghetti) than other years to adult coho caught at the Gitwinksihlkw fishwheels and we do not know how this will affect in-season mark-recapture estimates. The change in tag type is part of the research being conducted on Nass coho to assess mark-rate differences between Upper Nass coho stocks where significant mark rate differences were detected between stocks using the spaghetti tag. Catches of coho at the Gitwinksihlkw fishwheels continue to be well above average (1.7 times the average catch to week ending 22 August) so a good abundance has been detected; but the magnitude of the return cannot be fully assessed until a post-season review of the mark-recapture results can be completed.

The current run size estimate is well above average (51,000) to date based on mean returns from 1994 to 2008. The mean run size estimate to Gitwinksihlkw from 1994 to 2008 is 68,000. The run size target for Nass coho to Gitwinksihlkw is ~65,000 depending on harvests projected above Gitwinksihlkw and during typical Gitwinksihlkw fishwheel operation (July to early-mid September) as coho continue to pass the fishwheels after the fishwheel program ends operation. Based on the in-season data to date, the run size target to GW was achieved for 2009.

The in-season run size estimate for Nass coho will be a combination of mark-recapture and historical catch index methods. The mark-recapture estimates will fluctuate over a 7 day period due to mark rates stabilizing at Grease Harbour as coho tagged at Gitwinksihlkw pass the upstream Grease Harbour fishwheel sites over a 7-day period.

The net escapement estimate for Nass coho is 144,550 (with 8,366 estimated to have been harvested above GW to date). The net escapement target for Nass coho above Grease Harbour is ~60,000 during typical operations of the Gitwinksihlkw fishwheels from July to first or second week of September and was reached for 2009 based on in-season data.

Total counts of coho at Meziadin Fishway to 27 August are: 800 adults (14 tags) and 29 jacks. The 2009 cumulative adult count to date is above average (300) based on mean counts at the Meziadin Fishway from 1994 to 2008. The average total count of adult coho at Meziadin Fishway from 1994 to 2008 is 3,700. Coho begin passing the Fishway typically in mid-to-late August.

Nisga’a Fisheries is using a preliminary TRTC estimate for Nass coho of between 119,000 (pre-season) and 369,000 (in-season) for tracking the Nisga’a entitlement of Nass coho. The 2009 pre-season TRTC estimate was forecasting for a below average (147,000) return based on TRTC returns from 1994 to 2008; but in-season assessments are suggesting an above average return. Uncertainty of marine commercial and recreational catches, and lower/coastal escapement of Nass coho make it difficult to accurately estimate in-season TRTC and entitlement estimates for Nass coho. However, based on the current in-season TRTC estimate for 2009, the Nisga’a entitlement of Nass coho is between ~9,500 and ~19,200 (the maximum allowed by treaty). An additional allocation is also available as an underage (6,263) provision based on past year’s management uncertainty allowances; however, underages are only targeted in productive return years as assessed during the season.

The Nisga’a harvest estimate of Nass coho to date is 9,808. The total includes FSC catch (2,646) to week ending 22 August and sale fishery catch estimates to date (39 from individual sale and 7,123 from communal sale from GH fishwheels). Communal harvesting of coho from the GH fishwheels began on Sunday, 9 August and continues to date.

Area 3 commercial gillnet and seine harvests of coho to date are 1,933 (10,006 released). No estimates of the Nass component are available to Nisga’a Fisheries.

Total in-season harvest estimate of coho in Southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is 291,618 based on data to week ending 34 (22 August) from the ADFG website. Reported catches are above average (240,000) to week ending period. The average total catch of coho in southeast Alaskan gillnets and seine fisheries in Districts 101 to 104 is ~370,000 coho from 2000 to 2008. No estimates of the Nass component are available to Nisga’a Fisheries.

NASS PINK SALMON:

The total fishwheel catch (39,598) of pink salmon to 27 August is above the mean catch (25,000) for odd-year returns from 2000 to 2008. Specifically, pink catches (21,000) at the Gitwinksihlkw fishwheels to week ending, 22 August, are double the odd-year average catch (11,000) for the same week ending period.

Nisga’a Fisheries is using the Gitwinksihlkw catch information for in-season tracking of the Nisga’a entitlement. The TRTC estimate for Nass pink in 2009 is ranging between 1,053,000 (pre-season) and 2,000,000 (in-season) for tracking the Nisga’a entitlement of Nass pink that ranges between 129,000 and 271,000. The 2009 TRTC pre-season estimate was projecting to be just below average (1,150,000) based on TRTC returns of odd year pinks from 1995 to 2007; but current in-season assessments are suggesting a much larger return.

Note that pre-season and in-season forecasting of Nass area pinks are poorly developed for Area 3 currently. Nisga’a Fisheries is developing in-season methods with DFO for better predicting the magnitude of returns in the future based on fishwheel mean catches, Kincolith weir counts (when operated) and any stream survey information that can be collected (primarily from late July and early August data) to aid in managing Nass area pinks and tracking the Nisga’a entitlement.

The Nisga’a harvest estimate of Nass pinks to date is 28,037. The total includes FSC catch (7,105) to week ending 22 August and sale fishery catch estimates to date (20,932 from individual sales fisheries).

Area 3 commercial gillnet and seine harvest of pink to date are: 1,020,083 (910 released).

Total in-season harvest estimate of pink salmon in Southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is 17,306,425 based on data to week ending 34 (22 August) from the ADFG website. Reported catches are well below average (26,000,000) for the week ending period catches of odd-year pink returns. The average total catch of pink in southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is ~28,000,000 pink from odd year returns between 1999 and 2008. No estimates of the Nass component are available to Nisga’a Fisheries.

NASS CHUM SALMON:

The total fishwheel catch of chum salmon (65) to 27 August is below the mean catch (112) level based on total fishwheel catches from 2000 to 2008. Specifically, chum catches (36) at the Gitwinksihlkw fishwheels to week ending, 22 August, are below average (50) for the same week ending period.

Nisga’a Fisheries is currently using the pre-season TRTC estimate for Nass chum of 56,000 for tracking the Nisga’a entitlement (4,480) of Nass chum. The 2009 TRTC estimate is projecting a below average (93,000) return based on TRTC returns from 1994 to 2008. In addition, for the past two years the returns of Nass area chum have been well below the minimum escapement goal and concern for stock status has been raised by Nisga’a Fisheries to DFO. The overall stock status of Nass area chum since 2000 has prevented the opportunity to utilize the Nisga’a entitlement underages (~28,000) that occurred in the early years of implementing the Nisga’a treaty (2000 to 2002). In addition, when the returns have been above the escapement goal, the majority of the Nisga’a entitlement of Nass area chum has been foregone since 2002 in an attempt to rebuild stocks. Therefore, the Nisga’a entitlement of Nass chum in 2009 will be mostly foregone to continue the rebuilding of Nass Area chum stocks.

The pre-season and in-season forecasting of Nass area chums are poorly developed for Area 3. No reliable methods are currently available to estimate escapement during the season, track the status of the run or fully determine the Nisga’a entitlement.

The Nisga’a harvest estimate of Nass chum to date is 114. The total is FSC catch (114) to week ending 22 August. No Nisga’a sale fisheries for Nass chum are being permitted in 2009 to allow stock rebuilding in Area 3.

Area 3 commercial gillnet harvest of chum to date is 46,427 (26,252 released). No estimates of the Nass component are available to Nisga’a Fisheries.

Total in-season harvest estimate of chum in Southeast Alaskan gillnet and seine fisheries in Districts 101 to 104 is 1,159,564 based on data to week ending 34 (22 August) from the ADFG website. Reported catches are below average (1,227,000) to the week ending period reported. The average total catch of chum in Southeast Alaskan gillnets and seine fisheries in Districts 101 to 104 is ~1,500,000 chum from 1999 to 2008. No estimates of the Nass component are available to Nisga’a Fisheries.