White Sturgeon

Acipenser transmontanus

White Sturgeon

In 2003, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) identified six Nationally Significant Populations (NSPs) of White Sturgeon in Canada: Lower Fraser River, Middle Fraser River, Nechako River, Upper Fraser River, Upper Columbia River, and Kootenay River. The first two of these NSPs were declined for listing and the latter four were listed as Endangered under the Species at Risk Act (SARA) in August 2006. A final Recovery Strategy addressing the four listed NSPs was published in 2014.

Since the 2003 assessment, COSEWIC switched from the concept of NSPs to that of Designatable Units (DUs), and in November 2012, a COSEWIC re-assessment divided the species into four new DUs: Upper Columbia River, Upper Fraser River, Upper Kootenay River, and Lower Fraser River populations. These DUs are currently under consideration for listing under SARA; they cover the same geographic area as the NSPs, except the former Middle Fraser River, Nechako River, and Upper Fraser River NSPs are now combined into a single Upper Fraser River population DU.

Description

The White Sturgeon is the largest and longest lived freshwater fish species in North America, with some individuals reported at over six metres in length and 100 years of age. They have characteristic barbels on their snout, an extendable mouth, and a shark-like tail. Rows of diamond-shaped bony projections run lengthwise along their exterior; however, their skeleton is mainly composed of cartilage. Grey to white shading on the lower flanks distinguishes this species from green sturgeon.

Habitat

Globally, White Sturgeon are found only in western North America, and within Canada they are unique to British Columbia. Despite being a primarily freshwater species, individuals have been known to enter the sea, and the brackish water found in coastal rivers, estuaries, and bays.

In British Columbia, White Sturgeon occur in the Fraser and Columbia river systems, including the river mainstems, several of the larger tributaries, large lakes and -- in the lower Fraser system -- in flood plain lakes, sloughs, and the River's estuary. Primary watersheds where White Sturgeon have been confirmed include: the Nechako, Kootenay, Columbia, Bowron, McGregor, Stuart, Harrison and Pitt Rivers; the Kootenay, Stuart, Harrison, Pitt, Takla, and Trembleur Lakes; and the Arrow Lakes Reservoir. See the White Sturgeon Recovery Strategy for detailed habitat descriptions of each Nationally Significant Population, and the 2012 COSEWIC Status Report for detailed habitat descriptions of each Designatable Unit.

Adult White Sturgeon generally occupy deep backwaters adjacent to eddies; however seasonal habitat use varies. For example, foraging habitat is closely tied to the migratory patterns of their food sources. Overwintering sites generally have fine substrates with deep, slower-flowing water. Spawning in regulated rivers has been associated with deep, fast and turbulent waters over cobbles and boulder substrate, often downstream of the tailraces of dams. Spawning site characteristics vary in unregulated rivers. Juveniles are associated with slower-flowing water and fine substrates.

Threats

The primary human activities that threaten White Sturgeon in the wild are: direct habitat loss, river regulation, harvest of prey, introduction of invasive non-native fish species, direct and indirect harvest, and release of pollutants. Other threats are expanded on in the 2014 White Sturgeon Recovery Strategy.

Further Information

Several achievements contributing to the recovery of White Sturgeon have been realized in recent years: a 2007 Recovery Potential Assessment; a 2012 COSEWIC Status Report; and a 2014 White Sturgeon Recovery Strategy led by Fisheries and Oceans Canada and the Province of British Columbia in cooperation and consultation with many individuals, organizations, and government agencies. Next, an action plan outlining the measures required to meet the goals and objectives of the Recovery Strategy will be developed. Studies on the topics of abundance, genetics, habitat, ecology, aquaculture, life history, and traditional knowledge also continue to inform recovery efforts. A national recovery team including several working groups, environmental and stewardship organizations, First Nations, aboriginal organizations, various governments, and many others participate in recovery efforts.

The Nechako River, Upper Fraser River, Upper Columbia River, and Kootenay River NSPs of White Sturgeon are protected federally under SARA, and the four DUs assessed by COSEWIC in 2012 are under consideration for listing under SARA. More information about SARA, including how it protects individual species, is available on the Species at Risk Public Registry. Fisheries Protection and Pollution Prevention provisions of the Fisheries Act also provide protection to White Sturgeon.

To know if this species is protected by provincial laws, consult the province's website.

White Sturgeon

White Sturgeon

White Sturgeon

Scientific Name: Acipenser transmontanus

COSEWIC Status (NSPs): Non-active; reassessed as DUs in 2012

SARA Status (NSPs): Schedule 1, Endangered (Kootenay River, Nechako River, Upper Columbia River, and Upper Fraser River populations; August 2006)

COSEWIC Status (DUs): Endangered (Upper Columbia River, Upper Fraser River, and Upper Kootenay River populations; November 2012), Threatened (Lower Fraser River population; November 2012)

SARA Status (DUs): No status; under consideration for listing.

Region: British Columbia

Did You Know?

White Sturgeon use chemoreceptors on their barbels and electroreceptors on their snouts to help find prey in murky waters.

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