As long as the resources on which salmon, Pacific lamprey, and white sturgeon depended were maintained—i.e., the cool, clear waters, complex stream systems, and the interconnectedness of the parts—these anadromous species thrived and enabled the Indians of the Columbia River Basin to prosper. As described below, much of this has changed drastically in a relatively short time.
During the last century in the Columbia River Basin, salmon runs, once the largest in the world, have declined over 90%. The 7.4-12.5 million average annual number of fish above Bonneville Dam has dropped to 600,000. Of these, approximately 350,000 are produced in hatcheries (ODFW and WDFW 1995).
Spawning salmon populations in the Columbia River produced enough offspring historically to replace themselves fivefold. However, the magnitude of cumulative mortality impacts is now so large that these species are biologically unable to compensate, and populations cannot replace themselves on a consistent basis. Many salmon stocks have been extirpated from major portions of their historical range (Table 3.1). Furthermore, the majority of Columbia River Basin natural salmon populations are on a downward trend, and many are approaching extirpation (CRITFC 1992a). Snake River chinook and sockeye have been listed under the federal Endangered Species Act. What is considered to be a local population today may simply be a fragment of what was historically a large, continuous population. Declines in natural production are indicated generally by declining numbers of redds in tributary streams.
Since the completion of the hydropower system in the Columbia Basin, numbers of Pacific lamprey have declined dramatically compared with historical levels of abundance and distribution. For example, the name of the ancestral Nez Perce village Hasotino (located on present day Asotin Creek), means “the great eel fishery” (Spiden 1908). Counts at Bonneville Dam have exceeded 300,000 lamprey in the past (Starke and Dalen 1995). These counts include only those fish that passed the counting station during the 18 hours of counting, i.e., they do not include lamprey that passed through navigation locks or at night. Counts of Pacific lamprey returning over lower Snake River dams were in the thousands in 1969, but declined to hundreds by 1978 (Hammond 1979) and numbered only 40 individuals total in 1993 (L. Basham, Fish Passage Center, Portland, personal communication 1994). Although tribal proposals for lamprey recovery have been submitted since 1991, lamprey were not considered high priority when compared to salmon stocks. Recently, the CTUIR have received funding to research lamprey declines in the tribe’s ceded land, as well as address passage concerns at the Columbia Basin mainstem dams.
Colonization of the Columbia Basin by white settlers profoundly affected the sturgeon populations and habitat. Like other North American sturgeon populations, Columbia Basin white sturgeon were commercially exploited for their flesh and eggs (Bajkov 1949; Smith 1990). Prior to purposeful commercial harvest, vast numbers were simply killed because they damaged gear of commercial salmon fishers. Once a market was established, white sturgeon were commercially extirpated from the lower Columbia River by 1899 (Craig and Hacker 1940; Galbreath 1985).
White sturgeon populations today are considerably reduced, even though they are still found throughout much of their historical habitat (PSMFC 1992). Hydroelectric development on the Columbia and Snake rivers has created a series of reservoirs, which trapped and separated the single historical white sturgeon population into a number of separate land-locked (reservoir) populations (North et al. 1993). Populations above Bonneville Dam are characterized by the following river reaches: (1) Lower Columbia River above Bonneville Dam, (2) Mid-Columbia River, and (3) Lower Snake River.
The area located between Bonneville and McNary dams, contains three reservoirs. Bonneville Pool has a stable population with good recruitment. The Dalles and John Day pools contain depressed populations, with the John Day population the poorer of the two. The three reservoirs in Zone 6 support tribal commercial and subsistence fisheries, and a popular sport fishery (Hale and James 1993; Beamesderfer et al. 1995). Annual harvest of sturgeon populations between Bonneville and McNary dams ranged from 3,500 to 4,600 for the period between 1991 and 1993; the bulk of the harvest came from Bonneville Pool.
The Mid-Columbia River reach contains reservoirs and the longest free-flowing section of the Columbia River (the Hanford Reach) upstream from Bonneville Dam. All reservoirs within this section are subject to point and nonpoint source pollution, which may affect the reproductive success and recruitment of larval sturgeon (Anders and Beckman 1993; Glubokov 1990). Tribal subsistence fisheries occur within this reach, as well as consumptive sport fisheries.
The Lower Snake River contains reservoirs behind Ice Harbor, Lower Monumental, Little Goose, and Lower Granite dams. The Lower Granite Reservoir may be a rearing area for juvenile white sturgeon, with adult sturgeon being more prevalent in the free-flowing Snake River downstream from Hells Canyon Dam (Coon et al. 1977; Lukens 1985). The population in the free-flowing section of the Snake River appears to be stable.