Conservation of White Sturgeon in the Columbia River

Contributor: Colin Spence and Sara Muir
Location: Kootenay, British Columbia
Land Use: Fisheries
Habitat Type: Watercourse/Riparian
Project Timeline: 1995-2000

Highlights

The Conservation of Columbia River White Sturgeon project examines the distribution, abundance, life history and age structure of sturgeon in the lower Kootenay and Columbia River systems as a basis for the development of an international recovery plan for this important fish species.

• Introduction
• Challenges
• Process
• Actions
• Results
• Next Steps

• The White Sturgeon (Acipenser transmontanus) occurs along the Pacific Coast from California to British Columbia. Significant populations of White Sturgeon are found in only three large river systems – the Sacramento, the Fraser and the Columbia. The White Sturgeon is the largest and longest living fish in Canadian freshwater. White Sturgeon can reach up to 635 kilograms in weight and six meters in length, and have been estimated to live over one hundred and fifty years. Adults require fifteen to thirty years to reach sexual maturity, can spawn at intervals from two up to more than ten years, and release millions of eggs during a reproductive event.

  Prior to the 1900s the Fraser, Kootenay and Columbia rivers were abundant with White Sturgeon. Since the turn of the century, the reduction of critical feeding and rearing habitats due to hydroelectric dams, dyking and drainage projects have impacted White Sturgeon populations. As development continues to intensify in the in the Sacramento, Columbia and Fraser river basins, concerns for the long term survival of White Sturgeon continues to grow.

  Project Objectives
  The White Sturgeon Recovery Project aims at restoring White Sturgeon populations in the Columbia. The objectives for the first two years of this five year project include:

  1. taking a lead role in completing a collaborative Canada-US Recover Plan for Columbia River White Sturgeon

  2. documenting habitat conditions, timing and success of White Sturgeon spawning activity below Revelstoke and Waneta dams

  3. determining sizes of breeding populations at Waneta and Revelstoke

  4. planning and testing techniques that will assist in White Sturgeon recovery in the Columbia River.

  The objectives for the subsequent three years of this five-year project will be determined upon the completion of the joint Canada-US Recovery Plan, currently underway.

• In Canada, sturgeon are primarily resident in only two watersheds, the Fraser and the Columbia. In the Columbia River, their populations are much reduced due to hydroelectric dam development and other human impacts. Before construction of dams in the Columbia River, White Sturgeon ranged throughout the drainage – perhaps even past Lake Revelstoke, and certainly through the Arrow Lakes and over the US border into the southernmost reaches of the Columbia River.

  In BC, the construction of the Mica, Revelstoke, and Keenleyside dams along the Columbia River created impoundments, dividing White Sturgeon into groups where a single population once likely existed. In the US, the construction of Grand Coulee and numerous other dams on the Lower Columbia River resulted in similar “landlocked” situations for White Sturgeon populations. The construction of these dams eliminated salmon runs from the Upper Columbia and also caused changes to river flows, temperatures, dissolved gas levels and turbidity. This adversely affects many other fish species, such as Kokanee, which sturgeon depend on as a food source.

• The protection of the White Sturgeon has received national recognition. The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) has classified the White Sturgeon as Vulnerable while in British Columbia the fish is Red Listed with the potential for legal designation as endangered or threatened status. In 1994, through the combined action of the provincial fisheries program, Fisheries and Oceans Canada, and First Nations, a moratorium on the harvest of White Sturgeon was enacted in British Columbia. And in 1995, to better understand the status and life history of White Sturgeon, The Ministry of Water, Land and Air Protection (formerly the Ministry of Environment, Lands and Parks), through funding from the Habitat Conservation Trust Fund (HCTF) and Forest Renewal BC (FRBC), began a basic inventory and assessment of White Sturgeon populations in the Fraser and Columbia River systems.

  White Sturgeon in the Upper Columbia are transboundary, migrating freely between important habitats in the Columbia in BC and the state of Washington. Canadian and US agencies, First Nations (Tribes), BC Hydro, Bonneville Power Administration and other interests are coordinating their efforts through a joint Recovery Team. A similar process involving White Sturgeon in the Kootenay basin in the US and Canada is already well underway and serves as an excellent example of how such co-operative efforts can succeed.

• Recovery Planning
  A Recovery Plan for upper Columbia River White Sturgeon is being developed in cooperation with a number of Canadian and US agencies and other interests (see Partners). The Recovery Plan will guide activities on both sides of the border in the coming years, including strategies for culturing fish (use of hatchery supplementation), modifying dam operations, habitat manipulation, examining the role of predators, and a variety of related monitoring and research.

  Population Status and Broodstock Collection
  A conservation aquaculture program will be implemented to produce juvenile sturgeon for research purposes and to ensure the long-term survival of the population. Adult sampling to obtain broodstock for this program began in March 2001 and will continue periodically throughout the year. Hill Creek Hatchery, located north of Nakusp on Upper Arrow Lake, has been extensively modified to accommodate sturgeon production on a pilot basis. If successful, the program will likely be implemented on an ongoing basis over the next several years. As part of this program, adult sturgeon will also be sampled to obtain information on age structure, growth rates, and population size. This information will be used to assess progress in recovery efforts.

  Spawning Assessments – Waneta
  The most important known spawning site for White Sturgeon in the upper Columbia River is located near Waneta, at the outlet of the Pend d’Oreille River south of Trail, BC. Surveys of spawning activity at Waneta have been undertaken with some regularity since the early 1990’s. Artificial substrate mats have been used exclusively for this purpose. Substrate mat monitoring at Waneta in 2000 identified only two distinct spawning events. Given the moderate flow conditions, this number is low relative to what might have been expected based on data from other years. Additional study is required to improve our understanding of the factors controlling spawning activity and success in this area.

  Spawning Assessments – Revelstoke
  Spawning by Arrow Reservoir sturgeon below Revelstoke Dam (completed in 1984) was observed for the first time in 1999. Fertilized eggs were collected in this area much later (July 30-August 20), and at lower temperatures (9.2-11.6°C) than is typically observed for this species elsewhere in the Columbia basin. Extreme variations in river flow also occur because Revelstoke Dam generating facilities are used for load-shaping to meet instantaneous peak power demands. Pre-spawners were tracked to the same general area again in 2000 and substrate mats were again deployed. However, the pre-spawners left the area before the timing of spawning events observed in 1999 and could not be located for the remainder of the potential spawning season. The substrate mat program detected no evidence of spawning in 2000.

  Additional study is required to determine if spawning events similar to those in 1999 occur regularly. As part of this work, further attempts would be made to locate, tag and track pre-spawning Arrow Reservoir females to their spawning sites. Sampling with substrate mats would be coupled with the tracking program to confirm the extent, location and timing of spawning. Daily retrieval of substrate mats and follow-up egg stage analyses would be conducted, along with continuous temperature monitoring. The resulting data would be used to back-calculate the time of spawning, determine river discharges and estimate habitat conditions during egg deposition.

  Baseline Population Estimate
  The most recent estimate of population size for White Sturgeon in the Columbia River between Hugh Keenleyside Dam and the Canada-US border was obtained in 1996. In Arrow Reservoir and the Columbia River upstream to Revelstoke, ongoing work has resulted in annual refinements of the population estimate for that area over the past three years. As a pre-recovery baseline, an up-to-date estimate of population size should be obtained over the next year for the area between Keenleyside Dam and the border. Included in this work will be an updated assessment of age and growth in the population. A large portion of this work will be completed along with broodstock collection efforts in this area, expected to begin in late winter, 2001.

  Lower Arrow Adult Assessment
  Work to date on Arrow Reservoir has targeted the upper basin, from Burton (“the Narrows”) to Revelstoke. In fact, the vast majority of setline sampling has occurred at Beaton Flats on Upper Arrow Reservoir, reflecting high use in that area by existing sonic tagged fish. At the same time, many sturgeon sonic tagged in the Beaton area cannot be found during the summer months, suggesting the possibility they may be using a part of the basin where tracking has been limited. In 1999, one of the sturgeon sonic tagged at Beaton Flats was discovered in the Columbia River below Hugh Keenleyside Dam, providing clear evidence that these fish at least occasionally utilize Lower Arrow Reservoir and can be entrained through the dam. Additional setline sampling and tracking of existing sonic tags will be undertaken on Lower Arrow Reservoir to provide a better understanding of the importance of this area to White Sturgeon.

  Broodstock Options Review
  Some form of aquaculture is expected to be required as part of the recovery process for Upper Columbia White Sturgeon, at least as a means of meeting short term research requirements. A review of the options for providing eggs for an aquaculture program is required, including an assessment of the benefits, risks, logistics and costs. Options include the following:

  1. wild egg collection: modified substrate mats could be deployed at Waneta or Revelstoke to collect wild, fertilized eggs and transport these (or the resulting larvae) to a hatchery for rearing

  2. broodstock obtained ripe: fish could be obtained on spawning sites, allowing immediate spawning without extended holding or use of stimulating hormones

  3. broodstock obtained green: fish could be obtained well in advance of the spawning season and held at facilities where the onset of maturity would be controlled by hormone injections and controlled temperatures

  4. broodstock or brood obtained elsewhere: either adults, their hatchery offspring or possibly even wild juveniles could be brought in from other locations to supplement the population.

  5. bombination: some combination of the above-noted options could be implemented.

  Wild Egg Collection
  One of the recovery options being considered for upper Columbia White Sturgeon involves a partial fish culture approach, where naturally spawned and fertilized wild eggs would be collected for subsequent hatching/rearing at a hatchery facility. This offers the advantage of avoiding the risky and invasive process of collecting, holding and spawning broodstock. Additionally, it does not involve artificial mate selection.

  An experimental wild egg collection program is proposed to determine the best method of obtaining large numbers of eggs. This would be set up in the known spawning area at Waneta; the work could be performed in conjunction with other projects in the area. Existing work has already shown that eggs adhere very well to weighted substrate mats consisting of furnace filter material. Engineers will be consulted to determine if a large-scale version of this system could be used, or if other options would be more suitable. Issues directly related to egg transport and on-site incubation would also be addressed.

  Juvenile Recruitment Indexing – Evans to Kettle Falls
  Recruitment failure has been clearly demonstrated for Upper Columbia White Sturgeon on the basis of time-series adult life history data obtained from the early 1980’s through the 1990’s. During this time, however, juvenile sampling has been limited. Juvenile studies by US agencies on Lake Roosevelt in 1998 represented the first large-scale effort to detect young sturgeon in this part of the basin. Only one juvenile (33 cm) was caught in that work. Additional sampling by the Colville Tribe has generated annual catches averaging approximately two juveniles (<1 m fork length) per year over the past eight years. Further juvenile sampling is required to improve our understanding of locations and age classes of young fish in the area between Waneta and Kettle Falls. Small mesh (5 cm stretch mesh) gill nets would be used as the primary sampling method, following standard methods now employed throughout the Kootenay and Columbia systems for juvenile sampling. The data will contribute to the development of a recruitment indexing system. Where juveniles are found, their year classes may point to favorable environmental conditions that could be applied in recovery efforts. The results will also assist in furthering our understanding of juvenile spatial distribution and habitat preferences.

  Juvenile Recruitment Detection – Arrow Reservoir to Revelstoke
  The age structure of the small group (50-75) of White Sturgeon found in Upper Arrow Reservoir and the Columbia River upstream to Revelstoke indicates recruitment has not occurred since the completion of Hugh Keenleyside Dam in 1968. However, in 1999, spawning was detected in this part of the watershed near Revelstoke. Similar tracking of pre-spawners failed to detect evidence of reproduction within the same area in 2000. The 1999 spawning events may represent rare occurrences, with the rarity resulting from the small number of sturgeon in the area. If that is the case, few spawning events have likely occurred since the completion of Keenleyside and Revelstoke dams, potentially explaining the absence of young fish in sampling to date. Juvenile sampling aimed at evaluating the success of recent spawning activity is therefore required. Gill net surveys will be conducted in the area between Revelstoke and Beaton Flats on Upper Arrow Reservoir. These surveys will confirm the presence or absence of juveniles, assessing production resulting from recent spawning events.

  Estimation of Spawner Abundance via Genetics
  The number of reproductive sturgeon involved in spawning events at Waneta and Revelstoke is not well understood and cannot be effectively determined with the methods applied to date. At best, we are only able to estimate the minimum number of females spawners, based on the presence of radio or sonic tagged pre-spawners. Using existing genetic data from the upper Columbia as background and nuclear DNA/microsatellite techniques on newly collected eggs, probability analyses will be undertaken to provide estimates of the numbers of breeders at each site.

  Factors Controlling White Sturgeon Recruitment
  Successful recruitment of White Sturgeon is well documented in certain parts of the Columbia watershed. Although complete or partial reproductive failures are common in upper parts of the watershed, other locations (e.g. below Bonneville Dam) offer a high degree of reproductive success. Existing data on environmental conditions should be analyzed to determine which factors explain the observed variability in recruitment. Parameters such as temperature, turbidity, flows, TGP and fish species composition in and downstream of the spawning area would be included in the analysis. Where possible, direct comparisons to the Upper Columbia (i.e. Waneta and Revelstoke) would be made. As a minimum, the results of this work should point to deficiencies in data on environmental conditions and, optimistically, the work may reveal one or more factors that appear to control recruitment.

  Benthic Sampling
  The suitability of Upper Columbia River benthic conditions as habitat for young sturgeon is poorly understood. Factors such reservoir drawdown, substrate type, invertebrate production and contaminant levels could all affect juvenile production. A study to characterize such features is proposed, and would correspond with areas proposed for juvenile sampling. The program would consist of two components: one in the area between Revelstoke and Beaton Flats on Upper Arrow Reservoir, and the other between Waneta and Kettle Falls.

• White Sturgeon populations from Hugh L. Keenleyside dam to the US border have been studied since 1990. With funding from HCTF, further investigation began in 1995 to analyze other parts of the Columbia River basin, north of the US border. From these studies, White Sturgeon populations have been documented and their status evaluated for the Arrow Reservoir, Slocan Lake, Duncan Reservoir and the mainstream Columbia River. To date, an estimated twelve hundred sturgeon are believed to reside in the Columbia River, downstream of the Keenleyside Dam, while as few as 50-75 sturgeon are believed to exist within the Arrow Reservoir. Furthermore, it has been found that the sturgeon populations of these reservoir and lake systems share a similar age structure with, alarmingly, an almost complete absence of any younger juvenile sturgeon.

  Though there are apparently few young, studies do show that White Sturgeon are spawning. Sturgeon have been known to spawn below Waneta Dam, at the confluence of the Pend d’Orielle and Columbia River near the US border. In 1999, the studies funded by HCTF indicated a second spawning area on the Columbia River upstream of Arrow Reservoir, a short distance south of Revelstoke Dam. Evidence of reproduction has lead biologists to believe that there is indeed a chance for White Sturgeon to re-establish self-sustaining populations in the Columbia River.

• Future plans for the project will be spelled out in a Recovery Plan, currently under development and slated for completion in late 2001.

Acknowledgements

BC Hydro’s Hugh Smith received the 2001 Minister’s Environmental Awards (government category) for the Columbia River Sturgeon Recovery Plan.”Protecting the environment is a responsibility we all share,” said Water, Land and Air Protection Minister Joyce Murray. “These awards are an opportunity for government to recognize the efforts of people, groups and businesses that go the extra mile to promote exemplary environmental stewardship.”

Organizations and individuals from both Canada and the United States have been involved in the Conservation of White Sturgeon in the Columbia River project. Their efforts help to achieve the objectives of the project, and help to ensure the long-term survival of this important species. A special thank you to those you have dedicated their time to the project, and to the supporting projects including

• Habitat Conservation Trust Fund
• Ministry of Water, Land, and Air Protection
• Forest Renewal BC
• Ministry of Water, Land & Air Protection
• BC Fisheries; Fisheries and Oceans Canada
• BC Hydro
• Columbia Power Corporation
• Columbia Basin Trust
• Tech Cominco
• West Kootenay Power
• Canadian Columbia River Intertribal Fisheries Commission
• Washington Department of Fish and Wildlife
• Bonneville Power Administration
• US Fish and Wildlife Service
• Confederated Tribes of the Colville Reservation
• Spokane Indian Tribe.

Contacts

Ministry of Water, Land & Air Protection
Colin Spence
Rare and Endangered
401-333 Victoria Street
Nelson, BC Canada
V1L 4K3
Phone: 250-354-6777
Fax: 250-354-6332

Partners

Many partners have assisted in the Columbia River Sturgeon project:

Canadian partners

• Habitat Conservation Trust Fund
• Fisheries Renewal BC
• Ministry of Water, Land & Air Protection
• BC Fisheries
• Fisheries and Oceans Canada
• BC Hydro
• Columbia Power Corporation
• Columbia Basin Trust
• Cominco
• West Kootenay Power
• Canadian Columbia River Intertribal Fisheries Commission

US partners

• Washington Department of Fish and Wildlife
• Bonneville Power Administration
• US Fish and Wildlife Service
• Confederated Tribes of the Colville Reservation
• Spokane Indian Tribe

Project Partner Contacts

Ministry of Water, Land & Air Protection
Colin Spence
Rare and Endangered Fish
401-333 Victoria Street
Nelson, BC Canada
V1L 4K3
Phone: (250) 354-6777
Fax: (250) 354-6332

Habitat Conservation Trust Fund
Rod Silver
Manager, HCTF and Sp
780 Blanshard St.
Victoria, BC Canada
V8W 2H1
Phone: (250) 356-6124
Email: Rod.Silver@gems2.gov.bc.ca