Species Profile

Lake Sturgeon Western Hudson Bay populations

Scientific Name: Acipenser fulvescens
Taxonomy Group: Fishes
Range: Saskatchewan, Manitoba
Last COSEWIC Assessment: November 2006
Last COSEWIC Designation: Endangered
SARA Status: No schedule, No Status

Individuals of this species may be protected under Schedule 1 under another name; for more information see Schedule 1, the A-Z Species List, or if applicable, the Related Species table below.


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Image of Lake Sturgeon

Information about this species

General Description The Lake Sturgeon (Acipenser fulvescens) is a member of the family Acipenseridae. As a group, sturgeons are considered living fossils, having changed little from their ancestors of the Devonian Period. Lake Sturgeon is the only strictly freshwater species of sturgeon in Canadian waters. It also is the largest freshwater fish in Canada. Other common names include Rock Sturgeon, Common Sturgeon, Shell-back Sturgeon, Dog Face Sturgeon, and Great Lakes Sturgeon among others. The Lake Sturgeon has the following characteristics: Cartilaginous skeleton and shark-like caudal fin External bony scutes rather than scales on larvae and juveniles; less pronounced on larger fishes Pointed snout with four pendulous barbels Ventrally located mouth Dark to light brown in colour on back and sides; lighter belly Largest individual (Roseau River, Manitoba) was about 180 kg and 3 m long May live to over 100 years (oldest known specimen, about 154 years old from Lake of the Woods, Ontario) Distribution The distribution of Lake Sturgeon once extended from western Alberta to the St. Lawrence drainage in Quebec, and from southern Hudson Bay drainages to the lower Mississippi drainage. Its abundance and historic range in the United States are much reduced and it is considered endangered in many states. In Canada, Lake Sturgeon occur in rivers around southern Hudson Bay, in the Great Lakes, and in inland lakes and rivers from Alberta to Quebec. In Canada, eight designatable units (DU) have been identified for Lake Sturgeon based on genetic and biogeographical distinctions. Lake Sturgeon from the Churchill River system represent the Western Hudson Bay area (DU1). Habitat and Life History Lake Sturgeon are bottom-dwelling fish found in large rivers and lakes, at depths generally between 5 and 10 m, sometimes greater. Spawning occurs in the spring in fast-flowing water at depths between 0.6 and 5 m over hard-pan clay, sand, gravel and boulders. Sexual maturity is reached at 18 to 20 years in males and 20 to 24 years in females. The number of eggs may range from 50,000 to over 1,000,000 depending on the size of the fish, and incubation takes about 7 to 10 days in water of 13 to 15ºC. Larvae are negatively buoyant until the swim bladder starts to form about 6o days after hatching. The young-of-the-year grow rapidly and may reach 20 cm by the end of the first summer. Diet Lake Sturgeon feed on a variety of benthic organisms depending on the season, location and type of substrate. Some food items include small benthic fishes, molluscs, crayfishes, insect larvae, and on occasion, fish eggs. They may also feed in the water column on pelagic zooplankton such as Daphnia, and occasionally on insects at the surface. Threats Human activities represent the most important threat to Lake Sturgeon. Historically, commercial fishing caused precipitous declines in many Lake Sturgeon populations. None of these populations has fully recovered. More recently, the direct and indirect effects of dams pose important threats. Dams result in habitat loss and fragmentation, altered flow regimes, and may increase mortality by entrainment in turbines. Habitat degradation resulting from poor land use and agricultural practices also has had an adverse impact on many populations. Other threats may include contaminants, poaching and the introduction of non-native species. Similar Species Lake Sturgeon can be distinguished from Shovelnose Sturgeon (Scaphirhynchus platorynchus) by its more rounded snout and caudal peduncle.

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Documents

PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.

5 record(s) found.

COSEWIC Status Reports

  • COSEWIC Assessment and Update Status Report on the Lake Sturgeon (Acipenser fulvescens) in Canada (2007)

    The sturgeon family (Acipenseridae) contains 24 species, five of which are found in Canadian waters. Four of these are anadromous (spending part of the life cycle in freshwater and part in marine environments) and one, the lake sturgeon, is found only in fresh water. This species is one of Canada’s largest freshwater fishes with an extended snout, ventral mouth with four pendulous barbels, and a body covering of hard scutes and smaller denticles, rather than scales. This species reaches an age in excess of 100 years, lengths of up to 3 m and weights up to 180 kg.

COSEWIC Assessments

  • COSEWIC Assessment - Lake Sturgeon (2007)

    The species was considered a single unit and designated Not at Risk in April 1986. When the species was split into separate units in May 2005, the "Western populations" unit was designated Endangered. In November 2006, when the Western populations unit was split into five separate populations, the "Western Hudson Bay populations" unit was designated Endangered. Last assessment based on an update status report.

Response Statements

  • Response Statement - Lake Sturgeon, Western Hudson Bay populations (2007)

    A precipitous > 98% decline from 1929-1939 has been followed by a slow, steady decline in the Churchill River to the point that records of mature individuals are almost non-existent in the past five years. Historically, overexploitation probably was the primary threat; more recently, dams are probably the most important threat.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2007 (2007)

    2007 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.

Consultation Documents

  • Consultation Workbook on the addition of the Lake Sturgeon (8 designatable Units) to the SARA List (2007)

    Your opinion is being sought to assist the government of Canada in making an informed decision on whether to add the (Lake Sturgeon (8 designatable Units) to the Schedule 1 (the List of Wildlife Species at Risk) of the Species at Risk Act (SARA). Your input on the impacts of adding this species to the List is important. This workbook has been developed to give you an opportunity to provide Fisheries and Oceans Canada with your feedback, advice, and other comments regarding adding this species to Schedule 1 of SARA (Schedule 1 identifies which species are legally protected under SARA). Click here for the Cree version of the document in PDF. In addition to the original consultation period which ran from 2007-12-27 to 2008-04-25, the consultation response period for Lake Sturgeon populations within DU1, DU2, DU3, DU4, DU5, and DU8 has been extended from 2011-11-15 to 2012-03-31 to allow adequate time to complete the process.