Species Profile

Silver Chub Great Lakes - Upper St. Lawrence populations

Scientific Name: Macrhybopsis storeriana
Other/Previous Names: Silver Chub (Great Lakes - Western St. Lawrence populations)
Taxonomy Group: Fishes
Range: Ontario
Last COSEWIC Assessment: May 2012
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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Related Species

Species COSEWIC
Status
SARA
Status
Silver Chub Non-active Special Concern

Quick Links: | Photo | Description | Habitat | Biology | Threats | Protection | Other Protection or Status | National Recovery Program | Documents

Image of Silver Chub

Silver Chub Photo 1

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Description

The Silver Chub (Macrhybopsis storeriana) is a member of the Minnow family (Cyprinidae), and is the only species of the genus Macrhybopsis in Canada. It has the following characteristics: Body is stout and thick; average length is 100 to 150 millimeters long; maximum length is 231 millimeters; coloured pale grey-green on the back, becoming silver on the sides and silvery white below; a faint lateral band is usually present; moderate-sized subterminal mouth, and a snout that projects beyond the mouth; slender barbel, usually present at the end of the maxillary (corner of the upper jaw); eye diameter is relatively large; and caudal fin is distinctly forked and lightly pigmented, except for lower three-to-four rays, which are white.

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Distribution and Population

The range of the Silver Chub extends from Lake Winnipeg, east into the Great Lakes basin, and then south, largely through the Mississippi River system from Minnesota to the Gulf of Mexico. In Canada, the Great Lakes-Upper St. Lawrence populations are found in the Great Lakes basin, limited to Lake Erie and Lake St. Clair and the extreme southern portion of Lake Huron. The Saskatchewan-Nelson River populations (reassessed in 2012 as “Not at Risk”) are found in southern Lake Winnipeg and in the Assiniboine and Red river drainages of Manitoba, North and South Dakota and Minnesota.

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Habitat

In Ontario, Silver Chub is found in large lakes and connecting rivers at depths of 7.6–12 meters, although they have been caught as deep as 20 meters. Substrate is typically silt or sand, but the species is also sometimes associated with hard substrates, such as gravel, rubble, boulder or bedrock. It is not typically associated with aquatic vegetation.

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Biology

Reproduction of the Silver Chub is poorly understood. Individuals mature at age 1, and live to 3-to-4 years of age. One female can produce as many as 12,000 eggs. Silver Chub spawn in spring or early summer (May to July) at water temperatures between 19–23 degrees Celsius; however, there is uncertainty regarding where the species spawns and its spawning habitat requirements. In Lake Erie, the species has been observed to leave open water and move into near shore areas in early spring, possibly to begin spawning.

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Threats

The Silver Chub was considered common in Lake Erie until the 1950s. Its rapid decline in the 1960s coincided with habitat degradation and eutrophication caused by urban and agricultural runoff. The effects included poor water quality, extensive algal blooms and depleted oxygen levels in the water. Effects on invertebrate populations reduced prey sources. Although some threats have decreased in recent years (e.g., nutrient loading in Lake Erie), many still exist. Recent threats include aquatic invasive species, baitfish harvesting and climate change. Recent studies also suggest that the population numbers have dropped substantially in the past decade, and the risk of extirpation (i.e., extinct in Canada) is high.

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Protection

Federal Protection

The Silver Chub (Great Lakes-Upper St. Lawrence populations) has been recently reassessed from Special Concern to Endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). In 2012, COSEWIC split the populations into two separate units: 1) the Saskatchewan - Nelson River; and 2) the Great Lakes - Upper St. Lawrence. The Saskatchewan - Nelson River populations are not considered by COSEWIC to be at risk. Based on its previous assessment, the Silver Chub is currently listed under the federal Species at Risk Act as Special Concern. More information about SARA, including how it protects individual species, is available online at AquaticSpeciesAtRisk.ca or on the SARA Registry at SaraRegistry.gc.ca.

Provincial and Territorial Protection

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.

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Other Protection or Status

A management plan has been completed for the Silver Chub (2012) that identifies the conservation activities and land use measures needed to ensure, at a minimum, that a species of special concern does not become threatened or endangered. This management plan has benefited from the existing recovery strategy for the Essex-Erie region (an area that includes western Lake Erie, the Detroit River and the southern shores of Lake St. Clair), which includes the Silver Chub. Some measures have already been taken that will directly or indirectly benefit the species, such as the Lake Winnipeg Action Plan, which aims to reduce nitrogen and phosphorous levels in the lake, as well as existing monitoring programs that provide population data on Silver Chub populations.

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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.

4 record(s) found.

COSEWIC Status Reports

  • COSEWIC assessment and status report on the Silver Chub Macrhybopsis storeriana in Canada (2013)

    The Silver Chub (Macrhybopsis storeriana) is characterized by the presence of a slender barbel at the corners of the mouth, a rounded snout that greatly overhangs the mouth, a large eye on the upper half of the head, fewer than 50 lateral line scales, silvery sides lacking markings and an anteriorly located dorsal fin. It reaches a maximum length of 231 mm total length.

Response Statements

  • Response Statement - Silver Chub, Great Lakes - Upper St. Lawrence populations (2013)

    This small-bodied fish is native to the middle Great Lakes and has a small distribution range in Canada. Its abundance has declined substantially over the past ten years. Moreover, the longest consecutive time series of lowest abundance has been observed over the last five years. The species is assessed at high risk of extirpation from several threats including habitat degradation, competition with invasive exotic species, and climate change. This species is considered at risk in several border states, including Michigan and New York.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2011-2012 (2012)

    Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. COSEWIC held two Wildlife Species Assessment Meetings in this reporting year (September 1, 2011 to September 30, 2012) from November 21 to 25, 2011 and from April 29 to May 4, 2012. On February 3, 2012, an Emergency Assessment Subcommittee of COSEWIC also assessed the status of the Tri-colored Bat (Perimyotis subflavus), the Little Brown Myotis (Myotis lucifugus), and the Northern Myotis (Myotis septentrionalis). During the current reporting period COSEWIC assessed the status or reviewed the classification of 67 wildlife species. For species already found on Schedule 1 of SARA, the classification of 32 species was reviewed by COSEWIC and the status of the wildlife species was confirmed to be in the same category (extirpated - no longer found in the wild in Canada but occurring elsewhere, endangered, threatened or of special concern). The wildlife species assessment results for the 2011-2012 reporting period include the following: Extinct: 1 Extirpated: 4 Endangered: 29 Threatened: 10 Special Concern: 15 Data Deficient: 2 Not at Risk: 6 Total: 67 Of the 67 wildlife species examined, COSEWIC reviewed the classification of 49 species that had been previously assessed. The review of classification for 26 of those species resulted in a confirmation of the same status as the previous assessment (see Table 1a).

Consultation Documents

  • Silver Chub (Great Lakes - Upper St. Lawrence populations) (2014)

    The Silver Chub (Great Lakes-Upper St. Lawrence populations) has been reassessed from Special Concern to Endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). In 2012, COSEWIC split the populations into two separate units: 1) the Saskatchewan - Nelson River; and 2) the Great Lakes - Upper St. Lawrence. The Saskatchewan - Nelson River populations are not considered to be at risk. Based on its previous assessment, the Silver Chub is currently listed under the federal Species at Risk Act as Special Concern. As a species of Special Concern, a management plan has been developed. The recent change in the COSEWIC assessment will require a new listing decision under the Species at Risk Act. If the population is legally upgraded to Endangered, a recovery strategy will be developed.