BC Conservation Data Centre: Species Summary
Acipenser medirostris
Green Sturgeon
| Scientific Name: | Acipenser medirostris Ayres, 1854 | ||||||||||
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| English Name: | Green Sturgeon | ||||||||||
| Classification / Taxonomy | |||||||||||
| Scientific Name - Concept Reference: | Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea, and W.B. Scott. 1991. Common and scientific names of fishes from the United States and Canada. American Fisheries Society, Special Publication 20. 183 pp. | ||||||||||
| Classification Level: | Species | ||||||||||
| Species Group: | Vertebrate Animal | ||||||||||
| Species Code: | F-ACME | ||||||||||
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| Conservation Status / Legal Designation | |||||||||||
| Global Status: | G2 (May 2022) | ||||||||||
| Provincial Status: | S2S3N (Nov 2025) | ||||||||||
| BC List: | Blue | ||||||||||
| Provincial FRPA list: | |||||||||||
| Provincial Wildlife Act: | |||||||||||
| COSEWIC Status: | Special Concern (Nov 2013) | ||||||||||
| SARA Schedule: | 1 - Special Concern (Aug 2006) | ||||||||||
| General Status Canada: | 2 - May be at risk (2005) | ||||||||||
| Ecology & Life History | |||||||||||
| General Description: | This species is characterized by olive to dark green on back and sides; shovel-shaped snout with large fleshy barbels; barbels usually closer to mouth than to snout tip; large bony scutes along back and sides (22-33 scutes along sides); 1 row of preanal scutes. The total length of individuals of this species may be up to 213 cm. | ||||||||||
| Global Reproduction Comments: | Apparently this species spawns in the spring. Individuals become sexually mature at about 17 years (males) or approximately 21 years (females) (NMFS 2001). Females spawn at intervals of 3-7 years (NMFS 2001). Individuals live up to several decades. | ||||||||||
| Migration Characteristics: (Global / Provincial) | |||||||||||
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Nonmigrant: Local Migrant: Distant Migrant: Within Borders Migrant: |
N / Y / Y / na / |
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| Global Migration Comments: | Tagged green sturgeon from the Sacramento and Columbia Rivers are captured primarily in northern coastal and estuarine waters, with some fish tagged in the Columbia River recaptured as far north as British Columbia. While there is some bias associated with recovery of tagged fish through commercial fishing, the pattern of a northern migration is supported by the large concentration of green sturgeon peaking in the Columbia River estuary, Willapa Bay, and Grays Harbor in August. These fish tend to be immature; however, mature fish and at least one ripe fish have been found in the lower Columbia River. Genetic evidence suggests that Columbia River green sturgeon are a mixture of fish from at least the Sacramento, Klamath, and Rogue Rivers. The reasons for the concentration of green sturgeon in Oregon and Washington estuaries during the summer are unknown as there is no known spawning in these rivers and all stomachs examined to date have been empty. See NMFS (2003) for specific sources of this information. | ||||||||||
| Habitats: (Type / Subtype / Dependence) |
Ocean / Eelgrass Beds / Obligate
Ocean / Intertidal Marine / Obligate Ocean / Kelp Bed / Obligate Ocean / Marine Island / Obligate Ocean / Pelagic / Obligate Ocean / Reefs / Obligate Ocean / Sheltered Waters - Marine / Obligate Ocean / Subtidal Marine / Obligate |
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| Global Habitat Comments: | This species spends most of its life cycle in coastal marine waters, estuaries, and the lower reaches of large rivers. They ascend rivers to spawn, but specific spawning and rearing habitats are generally poorly known and increasingly uncommon in major rivers within its range. | ||||||||||
| Food Habits: |
Invertivore: Adult, Immature
Piscivore: Adult, Immature |
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| Global Food Habits Comments: | Adults of this species feed on bottom invertebrates and small fish. | ||||||||||
| Global Phenology: | |||||||||||
| Provincial Phenology: (1st half of month/ 2nd half of month) |
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| Colonial Breeder: | N | ||||||||||
| Length(cm)/width(cm)/Weight(g): | 213/ / | ||||||||||
| Elevation (m) (min / max): |
Global:
Provincial: |
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| Distribution | |||||||||||
| Endemic: | N | ||||||||||
| Global Range Comment: | The green sturgeon is comprised of two Distinct Population Segments (DPS) of which the southern Distinct Population Segment (sDPS) range in the western U.S. from California, in the lower Sacramento River primarily below the Red Bluff Diversion Dam, and occasionally in the lower Feather and Yuba Rivers (NMFS 2021). The northern Distinct Population Segment (nDPS) range includes the Klamath, Trinity, South Fork Trinity, and Eel Rivers (California) and the Rogue River (Oregon) (Israel et al 2009). Doukakis (2014) and Benson et al (2006) note occurrence of the green sturgeon nDPS in these rivers is limited to specific locations with suitable temperature and substrate habitat conditions suggesting limited occupancy. Total range extent, based on this description, and the definition of range extent for anadromous fish (includes spawning, rearing, and migration habitat) in Master et al. (2012), and using a GIS analysis, is about 2,000 km2 (Santos 2015a, 2015b). | ||||||||||
| Authors / Contributors | |||||||||||
| Global Information Author: | Hunting, K. | ||||||||||
| Last Updated: | May 17, 2022 | ||||||||||
| Provincial Information Author: | |||||||||||
| Last Updated: | |||||||||||
| References and Related Literature | |||||||||||
COSEWIC. 2004u. COSEWIC assessment and update status report on the green sturgeon Acipenser medirostris in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii +31pp. |
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Fisheries and Oceans Canada. 2026. Report on the Progress of Management Plan Implementation for the Green Sturgeon (Acipenser medirostris) in Canada for the period 2017 to 2021. Species at Risk Act Management Plan Report Series. Fisheries and Oceans Canada, Ottawa. iii + 6 pp. |
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Houston, J. J. 1988. Status of the green sturgeon, Acipenser medirostris, in Canada. Canadian Field-Nat. 102:286-290. |
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Lee, D. S., C. R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister, and J. R. Stauffer, Jr. 1980. Atlas of North American freshwater fishes. North Carolina State Museum of Natural History, Raleigh, North Carolina. i-x + 854 pp. |
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McGinnis, S. M. 1984. Freshwater fishes of California. University of California Press, Berkeley, California. viii + 316 pp. |
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Moyle, P. B. 1976a. Inland fishes of California. University of California Press, Berkeley, California. 405 pp. |
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National Marine Fisheries Service (NMFS). 2001. 90-day finding for a petition to list North American green sturgeon as threatened or endangered under the Endangered Species Act. Federal Register 66(241):64793-64795. |
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Nelson, J. S. 1984. Fishes of the world. Second edition. John Wiley & Sons, New York. xv + 523 pp. |
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Page, L. M., and B. M. Burr. 1991. A field guide to freshwater fishes: North America north of Mexico. Houghton Mifflin Company, Boston, Massachusetts. 432 pp. |
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Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea, and W.B. Scott. 1991. Common and scientific names of fishes from the United States and Canada. American Fisheries Society, Special Publication 20. 183 pp. |
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Scott, W. B., and E. J. Crossman. 1973. Freshwater fishes of Canada. Fisheries Research Board of Canada, Bulletin 184. 966 pp. |
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Wydoski, R. S., and R. R. Whitney. 1979. Inland fishes of Washington. The University of Washington Press, Seattle. 220 pp. |
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Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.
Suggested Citation:
B.C. Conservation Data Centre. 2022. Species Summary: Acipenser medirostris. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Nov 7, 2026).