17 



available scientific and convnercial data as in the previous 

 administrative record, NMFS changed its approach and is now relying 

 predominantly upon: (1) preseason projections of the 1994 return of fall 

 Chinook to the mouth oif the Columbia River; (2) guesses relative to the 

 1995 return; and (3) a new characterization of wild escapements that 

 have accrued since listing as being "low." Specifically, the December 

 28, 1994, Federal Register states: 



AJter the listing of Snake River fall Chinook salmon as a 

 thr»at0ned species in 1992, adult counts at Lower Granite Dam 

 during 1992 and 1993 remained at low levels. In-season estimates 

 for the 1994 return indicate that the situation has not 

 substantially improved . This lack of overall improvement during 

 recent years, exacerbated by the low returns of 1994 and expected 

 low returns in the next few years, indicates that the Snake River 

 fall Chinook salmon faces an imminent threat of extinction 

 throughout all or a significant portion of its range. The 

 projected adult return of listed Snake River fall chinook salmon 

 to the Columbia River during 1994 iM 803 fish, the second lowest 

 on record (Columbia River Technical Staffs (CRTS) 1994). As 

 discussed in CRTS (1994) and summarized in NMFS (1994), the number 

 of listed Snake River fall chinook returning in 1994 ia expected 

 to be below replacement level (i.e., fewer progeny th^n parents); 

 spawners have not replaced themselves In 7 or 8 of the last 9 

 years . 



Although final count data from the 1994 return will not be 

 available until February 1995, a tentative forecast of the 1995 

 run size suggests that the return will be about 60\ of that 

 expected in 1994 (NMFS and USFVS 1994). While it ia impossible to 

 make specific projections for returns of fall chinook over the 

 next 3 to 5 years, it ia possible to comment generally on the 

 prospects for decreasing run sizes. The number of offspring from 

 the 1991 brood is apparently quite small based on the record low 

 return of jacks in 1993. Therefore, the 5 year-old component of 

 the 1996 return is likely to be low. There was sufficient 

 escapement in 1992 and 1993 to allow for increased returns after 

 1995, but success of these runs will depend largely on 

 improvements in migration passage and ocean survival conditions . 



Although risks associated with small population sizes are also 

 applicable to Snake River fall chinook salmon, currently there is 

 no evidence of multiple , naturally spawning subpopulations of this 

 species. Still, the primary risk Co Snake River fall chinook 

 salmon remains the continued low numbers of spawning adults, and 

 genetic and demographic risks will increase if the population 

 remains at depressed levels for a number of consecutive years. 



Thus while in 1992, NMTS describes the count of 318 wild fall chinook 

 over Lower Granite Dam as representing'* considerable increase over the 

 1990 estimated escapement of 78 adults,' in 1994, NMFS describes counts 

 of 549 and 742 wild fall chinook over Lower Granite Dam in 1992 and 

 1993, respectively as escapements that 'remained at low levels.' 



The estimated wild escapement past Lower Granite Dam in 1990 was 78 

 fish, the lowest on record since 1980 when as Waples et al. (1991) 

 documented, a statistically significant change in growth rate parameters 

 of the population occurred. Since 1990, wild escapement past Lower 

 Granite Dam has bean estimated at 318, 549, 742, and 441 fish which 

 represent the twelfth highest, third highest, first highest, and sixth 

 highest escapements, respectively, of wild Snake River fall chinook 

 during this 15 year j>eriod. The average escapement of fall chinook 

 salmon past Lower Granite Dam from 1980 through 1990 was 377 fish; while 

 the average for 1991 through 1994 was 512 fish, a 36% increase. The 

 facts are that the estimated number of wild fall chinook passing above 

 Lower Granite Dam has increased by a factor of about one third over the 

 levels that escaped prior to listing and since the change in growth rate 

 parameters to this population occurred as a direct result of loss of 

 habitat and increase in migration difficulty due to dam construction. 

 Additionally, the escapement of wild fall chinook above Lower Granite 

 Dan in. 1994 was not the second lowest on record as the preseason 1994 

 forecast indicated (and as the December 28, 1994 Federal Register uses 



