• Native
  • Canada
  • United States

The White Sturgeon is found on the Pacific slope of North America from the Aleutian Islands, AK to Baja, CA. It is anadromous fish, spending most of its life in sea near the shore and can be found in estuaries of large rivers. It migrates far inland in large rivers to spawn. (Kee, et. al. 1981; Boschung, 1985).

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Pacific slope of North America from Aleutian Islands, Alaska, to Monterey, California (Lee et al. 1980). A land-locked population occurs in upper Columbia River system. Significant populations occur in the Sacramento, Columbia, and Fraser rivers. Introduced in lower Colorado River, Arizona (Page and Burr 1991).

There are several distinguishing characteristics of the white sturgeon. Its body is elongate and cylindrical and can be large, with sizes as large as 3.8 to 6 meters and weights as high as 630 kg.

It has no scales but five rows of "scutes" along the body. There are 11-14 plates in front of the single dorsal fin, 38-48 plates from the head along the central caudal axis, and 9-12 from the head to the pelvic fins. Dorsal color is light gray while the ventral surface is white.

The mouth is ventral, moderate in size and directed downward. The white sturgeon has no teeth, instead using its 'vacuum cleaner' like mouth that is capable of siphoning up food. This fish is recognized by its short broad snout with four barbels closer to the tip of the snout than the mouth. (Hart, 1973; Pacific States Marine Fisheries Commission 1996).

Range mass: 630 (high) kg.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

Sexual Dimorphism: sexes alike

Length: 340 cm

• Freshwater
• Marine

• Freshwater

• Freshwater

• Freshwater

• Freshwater
• Marine

• Freshwater

Historically, white sturgeon spent their life in several habitats; streams, rivers, estuaries, and marine waters. They are anadromous fish but may spend much or all of their lives in fresh water if they cannot reach the sea (Hart 1973). White sturgeon historically occurred on the Pacific Coast, reproducing in at least three large river systems, including Sacramento-San Joaquin River in California, the Columbia River basin in the Pacific Northwest, and the Fraser River system in British Columbia (Fish and Wildlife Service, Interior, 1994). The building of dams along the rivers has impacted the populations of white sturgeons by creating landlocked populations and destroying spawning grounds.

White sturgeon are still distributed throughout the river systems of the Pacific northwest, but these populations are isolated and their migration is limited within the series of pools and lakes that make up these new dammed rivers (Pacific States Marine Fisheries Commission, 2000)

Aquatic Biomes: rivers and streams; coastal

Habitat Type: Freshwater

Comments: Found at sea, usually near shore, and in large cool rivers or streams. Spawns probably either over deep gravel riffles or in deep holes with swift currents and rock bottoms (Wydoski and Whitney 1979). In the Fraser River (river km 98-181), British Columbia, six spawning sites were identified; five were in side channels within the meandering reach (km 98-143); one spawning site was in the main channel in the confined reach (km 145-181) (Perrin et al. 2003). Migrates upstream to spawn, moves back downstream when spawning is completed.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Some are anadromous and make extensive saltwater migrations. Many move more locally from estuaries to fresh water, or farther inland within fresh water, to spawn.

White Sturgeon have been described as opportunistic feeders, feeding on the bottom with their long snouts and using their barbels to detect food. When small they feed on clams, mussels, crayfish, worms, and fish eggs. At a larger size, they prey on fish such as smelt, anchovies, lamprey, shad and salmon.

Comments: A bottom feeder. Young feed mostly on the larvae of aquatic insects, crustaceans, and molluscs. A significant portion of the diet of larger sturgeon consists of fish.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 6 - 20

Comments: Lee et al. (1980) mapped approximately 24 collection sites in 17 waterways.

10,000 to >1,000,000 individuals

Comments: Abundant within portions of the range. Commercial catch has ranged from 10,000 to 50,000 lbs/yr recently.

Average lifespan

Status: wild: 100.0 years.

Average lifespan

Status: wild: 80.0 years.

Average lifespan

Status: wild: 82.0 years.

The exact reproductive window for white sturgeon is not known, however for sturgeons in general the males reproduce for 10 to 20 years and females for 15 to 25 years. The size or age of maturity is variable, and spawning occurs when the physical environment permits vitellogenesis (egg development) and cues ovulation. Landlocked sturgeons have been observed to spawn during periods of peak river flow with high water velocities that disperse and prevent clumping of the eggs. White sturgeon are broadcast spawners because they release their eggs and sperm in fast water. Information from Fish and Wildlife Service (1994)

Average age at sexual or reproductive maturity (male)

Sex: male: 6022 days.

Average age at sexual or reproductive maturity (female)

Sex: female: 8212 days.

In the Columbia River, spawns May-July (Wydoski and Whitney 1979). In California, spawning apparently occurs between mid-March and early June (Moyle 1976). Spawning occurs at intervals of 4 to 11 years. Larvae hatch from eggs in 1-2 weeks. Males may reach sexual maturity in about 9 years, females in 13-16 years (Wydoski and Whitney 1979). May live over 100 years.

• 1996
  Endangered
  (Baillie and Groombridge 1996)

In 1994, the population of White Sturgeon located in the Kootenai river was granted endangered status. The population has been declining since the 1960's and there has been a complete lack of recruitment of breeding juveniles in the population since 1974. The decline corresponds to the opening of the Libby Dam in Montana and possibly from poor water quality and the effects of contaminants (Fish and Wildlife Service 1994).

Joint efforts between Canada and the United States are underway to address the needs of the Kootenai population by developing a regional recovery strategy (Duke, 2000).

US Federal List: endangered

IUCN Red List of Threatened Species: critically endangered

Canada

Rounded National Status Rank: N2 - Imperiled

United States

Rounded National Status Rank: N4 - Apparently Secure

Rounded Global Status Rank: G4 - Apparently Secure

Reasons: Large range along the eastern Pacific Ocean; depleted to very low population levels in the early 1900s; has since rebounded, but spawns in relatively few river systems; some populations exhibit very low natural recruitment due to anthropogenic changes in river conditions.

Degree of Threat: B : Moderately threatened throughout its range, communities provide natural resources that when exploited alter the composition and structure of the community over the long-term, but are apparently recoverable

Comments: Populations were severely reduced by commercial over-fishing in the late 1800s-early 1900s (Parsley et al. 2002). As of the early 1990s, populations in Canada were "healthy" but under increasing pressure from fisheries (Lane 1991).

White sturgeons have been detrimentally impacted by physical and ecological barriers and population fragmentation caused by dams and their impoundments. For example, dams on the Columbia River have restricted movements of white sturgeons, and impounded fishes are effectively prevented from accessing the river's estuary and the Pacific Ocean (Rien and North 2002). Dam operations during low flow produce erratic conditions for spawning and recruitment (Parsley and Beckman 1994, Beamesderfer et al. 1995).

Dams on the Snake River have reduced free-flowing habitat by 37 percent (Cochnauer 2002). Most hydroelectric dams on the Snake River were never fitted with fish ladders adequate to allow upstream passage of white sturgeons (Cochnauer 2002). A simulation study of factors controlling recruitment in the Middle Snake River suggested that poor water quality during summer may have a strong negative effect of recruitment in the river segments between Swan Falls Dam and Hell's Canyon Dam (Jager et al. 2002). In segments with better water quality, populations in short river segments may be limited by larval export whereas populations in longer segments may be less limited by any single factor. Factors in an upstream segment may significantly influence downstream neighbors (Jager et al. 2002).

In the Kootenai River ecosystem, drastic anthropogenic changes to the river have led to natural recruitment failure for 30 years, with several exceptions. Apparently, during some years, natural recruitment failure was due to female stock limitation whereas in other years recruitment failure was due to one or more postspawning early life history mortality factors (Anders et al. 2002). Contaminants in the river have been implicated as a possible cause of poor reproductive success, but further study is needed (see Kruse and Scarnecchia 2002).

Management Requirements: Increased river discharge during the spawning season is one of the management needs for the Kootenai River population (see recovery plan).

Catch-and-release regulations in the Hells Canyon reach of the Snake River in Idaho, Oregon, and Washington over 30 years have allowed that population to increase in size and have improved population structure, but it may take another 25-30 years for the older age-class segment of the population to show a response (Cochnauer 2002).

Sturgeons transplanted from a robust population in the free-flowing lower Columbia River downstream from Bonneville Dam to Dalles Reservoir showed good survival and growth, indicating that such transplants may be effective in supplementing populations that have low recruitment (Rien and North 2002). However, harvest needs in the lower Columbia may limit use of this population in mitigation for lost productivity in Columbia River impoundments (Rien and North 2002).

Management Research Needs: More needs to be learned about the influence of abiotic and biotic factors on spawning and subsequent recruitment (Anders et al. 2002). It is known that year-class strength is determined within 2-3 months after spawning, and that increased river discharge combined with suitable water temperatures from spawning through first exogenous feeding result in greater recruitment, but little is known about the importance of food availability or losses due to predation in determining year-class strength (Parsley et al. 2002).

Evolutionarily significant units should be determined so that potential donor and recipient populations for translocations can be identified (Rien and North 2002).

Global Protection: None. No occurrences appropriately protected and managed

Needs: Protect spawning streams from impassible obstructions.

The size combined with the "characteristic quality of its flesh" makes it a valuable game fish in areas were it is not protected. Its roe can be used for caviar, and Columbia river roe production is "second only to the former Soviet Union" (Hart 1973; Pacific States Marine Fisheries Commission 1996).

Comments: Subject to commercial, native, and increasingly popular sport fisheries in the Fraser and Columbia river in British Columbia (Lane 1991).

Comments: Gene sequencing data of Birstein and DeSalle (1998) indicate that there are least three main clades within Acipenser: A. STURIO-A. OXYRINCHUS, A. SCHRENCKII-A. TRANSMONTANUS, and all Ponto-Caspian species plus A. DABRYSNUS and Brevirostrum.

Krieger et al. (2000) examined phylogenetic relationships of North American sturgeons based on mtDNA sequences and found that (1) nucleotide sequences for all four examined genes for the three Scaphirhynchus species were identical; (2) the two Acipenser oxyrinchus subspecies were very similar in sequence; (3) A. TRANSMONTANUS and A. MEDIROSTRIS were sister taxa, as were A. FULVESCENS and Brevirostrum (in constrast to Birstein and DeSalle 1998).