The Problem:
Development of the Columbia River Basin hydropower system has severely impacted populations of white sturgeon throughout the basin. These impacts have limited treaty and non-treaty commercial fisheries as well as recreational fisheries on white sturgeon both in the Columbia River downstream from Bonneville Dam and populations impounded in Bonneville, The Dalles, and John Day reservoirs with vulnerability to over-fishing increasing as you move further upstream (Beamesderfer et al. 1995). Sturgeon populations upstream from McNary Dam can currently support only catch-and-release recreational fisheries on naturally produced fish. Fishing for white sturgeon has been prohibited upstream from McNary Dam, including all Canadian waters of the Columbia River. The white sturgeon population in the Kootenai River was listed as endangered in 1994 under the U.S. Endangered Species Act (USFWS 1994) and a recovery plan was completed in 1999 (USFWS 1999... ).

Extensive development of hydropower dams throughout the Columbia River Basin during the past century has severely fragmented free-flowing, large river habitats (National Research Council 1996) occupied by white sturgeon. Anadromous white sturgeon historically made migrations throughout the Columbia and Snake rivers for spawning and feeding, but currently struggle to use existing dam fishways for passage (North et al. 1993; Parsley et al 2007). One important result of such river fragmentation for white sturgeon is the creation of a series of relatively isolated sub-populations (Jager et al. 2000; Secor et al. 2002). This is critical for a migratory species like white sturgeon, where fragmentation by dams may artificially impose limited, and primarily, downstream migration and gene flow. Impoundment and dam operations may also alter seasonal river discharge and thermal regimes altering migration, limiting habitat availability, or affect timing, location, or success of reproduction (Auer 1996; Cooke et al. 2002; Jageret al. 2002; Secor et al. 2002). Presence of dams and impoundments also severely restrict migrations of at least two principal food sources for white sturgeon: eulachon Thaleichthys pacificus and Pacific lamprey Lampetra tridentata.

In addition to the effects of dams themselves, operation of the hydropower system has resulted in decreased productivity in many white sturgeon populations. Alterned flow regimes and increased water depths, have resulted in reduced water velocities over extensive areas (Parsley and Beckman 1994). In the Columbia River, white sturgeon spawning and egg incubation usually occur from April through July in the swiftest water available (Parsley et al. 1993), and the amount of spawning habitat for white sturgeon increases as discharge increases (Parsley and Beckman 1994). Hydropower production has reduced spring and summer discharges (Ebelet al. 1989), decreasing the amount of spawning habitat. During years of reduced river runoff, the lack of high-quality spawning habitat in impounded reaches may preclude successful reproduction by white sturgeon. As a result, many impounded white sturgeon populations are not as productive as they once were, and some populations in upper reaches of the Columbia River basin may already be facing extirpation.

Possibly related to poor spawning conditions, white sturgeon in impounded reaches often experience year-class failures because of poor recruitment to age-0 (Parsley and Beckman 1994; Anders et al. 2002; Parsley et al. 2002). Although recent population estimates in Bonneville, The Dalles, and John Day reservoirs (Rien 2007, Mallette 2008; Mallette 2009) are consistent with or higher than previous estimates (Beamesderfer et al. 1995), juvenile fish have remained relatively scarce in most years (Anders et al. 2002; Parley et al. 2002).

Though hydroelectric development has reduced the availability of spawning habitat, it has increased the area physically suitable for age-0 and juvenile white sturgeon in impounded reaches (Parsley and Beckman 1994). Impoundment has increased water depths and reduced water velocities upstream from the dams. Since young sturgeon use the deeper and slower water, this has caused physical rearing habitat to increase. Spawning failures and low numbers of recruits to age-0 when spawning is successful have resulted in relatively few fish occupying this available habitat.

Project Overview:
This project includes a series of closely coordinated and complementary activities in the Columbia River upstream of Bonneville Dam and downstream of McNary Dam with the potential for expansion in Columbia River up to Lake Roosevelt and in the Snake River downstream of Lower Granite Dam depending on level of funding.  Activities of baseline-funded project include stock assessment, monitoring the biological responses to mitigation actions, and monitoring sustainable fisheries in Bonneville, The Dalles, and John Day Pools only.  Modular additions to this project are also proposed subject to independent funding.

1986-1998 Project Phase:
Concern about the effects of the hydropower system on white sturgeon lead to a White Sturgeon Research Needs Workshop in 1983 conducted by Battelle Pacific Northwest Laboratory and the Bonneville Power Administration (Fickeisen et al. 1984) to facilitate further efforts by the Bonneville Power Administration’s Division of Fish and Wildlife in developing a research program for Columbia River Basin white sturgeon. It was determined that the research would be conducted under the resident fish section – specifically measure 804 (e) (8) – of the Northwest Power and Conservation Council’s Fish and Wildlife Program, which states that “Bonneville shall fund research to determine the impacts of development and operation of the hydroelectric power system on sturgeon in the Columbia River Basin…”(Fickeisen, 1985). The project began in 1986 and until 1992, work under this project concentrated on determining the status and habitat requirements of white sturgeon populations in the Columbia River downstream from McNary Dam (Beamesderfer and Nigro 1993) and on the identification of potential methods for protecting, mitigating and restoring white sturgeon populations. Conclusions from this work included: (1) dams limit movements of white sturgeon and have functionally isolated populations, (2) the status and dynamics of each population are unique, (3) productivity in reservoirs is less than in the unimpounded area downstream from Bonneville Dam, (4) recruitment and subsequent population size are limited by the effects of river discharge on spawning habitat, which is restricted to high-velocity areas immediately downstream from dams, (5) reservoirs provide large areas of suitable habitat for juvenile and adult white sturgeon, but compensatory population responses may reduce productivity if carrying capacity is reached, and (6) over-fishing for white sturgeon had occurred in Bonneville, The Dalles and John Day reservoirs and population collapse was likely if high exploitation continued.

Based on these conclusions, recommendations for further work included: (1) intensify management of fisheries for impounded populations, (2) evaluate if augmented river discharge in May and June improves spawning and recruitment, (3) evaluate the feasibility of enhancing depleted populations by transplanting juvenile white sturgeon from populations downstream from Bonneville Dam, (4) identify habitat requirements of sub adult and adult white sturgeon, quantify amounts of suitable habitat, and evaluate constraints on enhancement, (5) refine and evaluate hatchery technology for enhancement of threatened populations of white sturgeon, and (6) investigate the need and potential measures for protecting and enhancing populations upstream from McNary Dam.

1998-2010 Project Phase:
By 1998, much of the recommended work had been completed or was well underway: intensive fisheries management had become an ongoing component of the project, work to evaluate the feasibility of transplant supplementation was complete, and a broad recommendation for flows to provide spawning habitat was made. Therefore, a new phase of the project was started. In this phase, from 1998-2010, intensive fisheries management and transplant supplementation mitigation activities were fully implemented, investigations into habitat, flow, and enhancement measures were completed, and work to evaluate hatchery technology for enhancement mitigation began. Work associated with hatchery technology development was removed from the project during the 2003 - 2010 phase of work due to the combined effects of level or reduced funding and inflation. Likewise, annual recruitment indexing in the Lower Snake River reservoirs was discontinued in 2006 due to the combined effects of level or reduced funding and inflation. Project activities incorporated the continued implementation of mitigation actions from previous phases in Bonneville, The Dalles and John Day reservoirs, including: (1) intensive harvest management, (2) three year rotational stock assessments and monitoring of population responses to mitigation actions, (3) investigating and refining estimates of individual fish growth, (4) describing maturational status and reproductive potential of white sturgeon, (5) annual sampling to index relative abundance of age-0 white sturgeon and relating changes in recruitment to changes in environmental conditions, and (6) monitoring survival, growth and contribution to fisheries of transplanted white sturgeon. Furthermore, we coordinated with other Columbia Basin sturgeon projects to address the protection and enhancement of populations upstream from McNary Dam, including participation in the development and implementation of white sturgeon management plans directed at the restoration of white sturgeon populations in Priest Rapids, Wanapum, and Rocky Reach reservoirs on the Columbia River.

2010-2019 Project Phase:
The project continued to reduce and eliminate work elements and/or frequency of work due to flat funding (functionally reduced budgets) during the 2010-2019 project phase.  Since 2012, the project no longer conducts any research, population monitoring, or fisheries monitoring above McNary Dam. Project activities in Bonneville, The Dalles and John Day Reservoirs included: (1) intensive harvest management, (2) three year rotational stock assessments and monitoring of population responses to mitigation actions, (4) annual sampling to index relative abundance of age-0 white sturgeon and relating changes in recruitment to changes in environmental conditions.

2019-2025 Project Phase: Assuming the project scope will not be further reduced due to flat funding (functionally reduced budgets), we will continue to monitor white sturgeon population abundance and size structure, on a triennial basis in in Bonneville, The Dalles, and John Day reservoirs as well as conducting age-0 indexing surveys annually in these three reservoirs through annual creel surveys.  We will also continue to monitor white sturgeon harvest in Bonneville, The Dalles, and John Day reservoirs.  The project proponents have proposed restoration of actions to achieve the original project goals and objectives during during the 2020 project review process.  However, restoration of previous work elements and/or new research actions would be contingent upon an infusion of new additional BPA funding.
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