Lyons Ferry Hatchery Evaluation Fall Chinook Salmon Annual Report: 2005

This report summarizes activities by the Washington Department of Fish and Wildlife’s (WDFW) Lower Snake River Hatchery Evaluation Program from 16 April 2004 to 15 April 2005.

Fall Chinook salmon broodstock were obtained from the Lyons Ferry Hatchery (LFH) ladder from 7 September until 18 November and the adult fish trap at Lower Granite (LGR) Dam from 6 September until 20 November.

Fall Chinook were spawned at LFH from 18 October to 29 November with the peak spawn days occurring during the 15th and 16th of November. We processed 2,709 adults and jacks trapped at LFH, 964 adults and jacks trapped at LGR, and returned 89 fish to the Snake River. Many (29.5%) of the males were used multiple times due to mating protocol constraints.

This was the third year that Snake River natural origin fish were included in broodstock (5.3 % of the fish spawned). In addition this was the first year strays were purposely used in broodstock (3.2 % of broodstock) since 1989. These changes occurred because of co-manager and NOAA agreements that strays should be kept to less than 5% of the broodstock.

We collected 4,929,630 green eggs. Egg mortality to eye-up was 4.6% and 1,180,000 eyed eggs were shipped to other hatcheries resulting in 3,562,700 eyed eggs available for production. In February 2006, 154,100 fry (progeny of matings in which one parent was a stray) were destroyed and 30,000 fry from these crosses were shipped to NPT. Following an additional 2.89% (103,037) sac-fry loss, total fry ponded for production in rearing ponds was 3,275,563.

In 2005, WDFW released a total of 1,116,852 subyearlings (2004 BY) into the Snake River at LFH and Couse Creek boat launch, and the Grande Ronde River near the mouth of Cougar Creek. An additional 1,203,000 were transferred to other agencies. Survival of subyearlings from green egg to transfer and release was 90.8%. We also released 224,853 yearlings (2003 BY) with a CWT, adipose clip, and a red VIE behind the left eye, and 225,147 fish with a CWT and red VIE behind the left eye from LFH in April of 2006. Survival of yearlings from green egg to release was 90.1%.

WDFW staff conducted adult salmon surveys on the lower Tucannon River between 24 October and 6 December 2005. Redd counts were expanded to account for areas not walked. We estimate the total number of redds at 67, and escapement was 201 fish based on an estimate of 3 fish per redd. The composition of 10 fall Chinook carcasses recovered indicate the majority of adults spawning in the Tucannon were our-of-basin strays (66.7%). Only one jack was recovered and it was of LF/Snake River hatchery origin.

Naturally produced juvenile fall Chinook (BY04) were observed at the Tucannon River smolt trap (Rkm 3.0) from 31 January through 30 June 2005. Based on 2005 smolt trap estimates and 2004 fall Chinook redd counts downstream of the trap, we estimated that 72,705 naturally produced fall Chinook smolts emigrated from the Tucannon.

The run of fall Chinook to LGR Dam was 11,638 adults and 2,347 jacks. The composition of the reconstructed run for LF/Snake River hatchery, LF/Snake River natural, and out-of-basin strays was 64.7%, 24.5%, and 10.8%, respectively. This is the first year bounds were placed around these estimates.

LSRCP returns of LF/Snake River hatchery origin fish to the Snake River basin (LFH, LGR, Tucannon River) totaled 8,476 adults and 2,276 jacks which was only 58.8% of the number required to meet mitigation.

Take of ESA listed LF/Snake River hatchery origin fall Chinook totaled 3,072 fish (including 33 returned to the Snake River), and 252 (38 returned to the Snake River) LF/Snake River natural origin fish.

LF/Snake River hatchery fall Chinook have a high fidelity to the Snake River. Of the 4,285 fish with CWTs recovered outside of the Snake River, approximately 0.1% of the fish were recovered at hatcheries, 1.2% at hatchery racks, and 0.1% during carcass surveys. The majority of recoveries outside the Snake River basin were in fisheries. The majority of ocean recoveries of adults from yearling and subyearling smolt releases occurred in British Columbia and Washington waters.