Recovery plan for Kootenai River white sturgeon (Acipenser transmontanus)

Abstract

Summary The white sturgeon (Acipenser transmontanus) of the Kootenai River was listed as endangered on September 6, 1994 by the United States Fish and Wildlife Service. This transboundary population, residing in Kootenay Lake and Kootenay River in Canada, and the Kootenai River in the US, has been in general decline since the mid‐1960's. There has been very little recruitment to this population in the last 20 years. This population became isolated from other white sturgeon populations of the Columbia River basin during the last ice age of approximately 10,000 years ago. The population adapted to the pre‐development conditions of the Kootenai system, with a high spring freshet and extensive side channel and low‐lying delta marshlands. Modification of the Kootenai River by human activities, such as industrial developments, floodplain dyking, and dam construction has changed the hydrograph of the Kootenai River, altering sturgeon spawning, incubation and rearing habitats and reducing overall biological productivity. A Kootenai River white sturgeon draft recovery plan was prepared by the US Fish and Wildlife Service in cooperation with other agencies in the US and Canada. The plan was peer reviewed and there was a parallel public consultation process, where public commentary was invited from both sides of the international border. The short‐term recovery objectives of the recovery plan are to prevent extinction and re‐establish successful natural recruitment. The identified long‐term objectives are the re‐establishment of a self sustaining population and the restoration of productive habitat, in order to downlist to threatened status and subsequently delist this population when recovery is well established. Specific actions needed for recovery include spring flow augmentation during the reproduction period; a conservation aquaculture program to prevent near‐term extinction; habitat restoration, and research and monitoring programs to evaluate recovery progress.

Estimating Differences in Growth and Metabolism in Two Spatially Segregated Groups of Columbia River White Sturgeon Using a Field-Based Bioenergetics Model

“…Contemporary impacts are primarily dominated by the effects of hydroelectric development and flow regulation in all three river basins [5], with the notable exclusion of the mainstream Fraser where dams are absent. The continued decline of white sturgeon in several spatially isolated populations within these watersheds has led to the species being listed as endangered in Canada [6,7] and the Kootenai River within the Columbia drainage in the United States [8].…”

Kootenai River White Sturgeon Recovery Implementation Plan and Schedule; 2005-2010, Technical Report 2004-2005.

“…The accompanying implementation schedule identifies annually implemented core program elements and the timing and progression of additional measures designed to recover Kootenai River white sturgeon. Efforts to re-establish natural recruitment of Kootenai River white sturgeon initially focused on flows and experimental alteration of Libby Dam operations (USFWS 1996;Duke et al 1999;USFWS 1999). Since 1994, Libby Dam discharges during spring have been augmented and shaped in an ongoing but unsuccessful attempt to stimulate natural recruitment of Kootenai sturgeon.…”

“…A variety of interrelated factors have clearly contributed to the decline of Kootenai white sturgeon; various hypotheses for recruitment failure are not mutually exclusive (Anders 1991;Anders and Richards 1996;Duke et al 1999;USFWS 1994;1996;1999;Anders et al 2002). Anders et al (2002) suggested that Kootenai River white sturgeon recruitment failure is likely the result of additive mortality from: 1) increased predation efficiencies due to low turbidity, velocity, and an relative increase in predatory fishes, 2) a reduced number of eggs produced by a dwindling spawning population, and 3) spawning in habitat lacking interstitial space (embryo suffocation).…”

“…Recruitment has failed, in part because fish are currently spawning at sites where or when conditions appear unsuitable for successful incubation and early rearing. Research to date suggests that recruitment failure is caused by egg or larval suffocation, predation and/or other mortality factors associated with these early life stages (Anders 1991;Anders and Richards 1996;Duke et al 1999;USFWS 1999;Anders et al 2002).…”

Dam-lake Operation to Optimize Fish Habitat

“…There are a few hypotheses that relate the decline in white sturgeons to the change in river hydraulics and sediment transport. Duke et al (1999) outlined a hypothesis that describes how Libby Dam might affect the sturgeon spawning.…”