Copper Redhorse

Moxostoma hubbsi

SARA Status
No Status
NS
Special Concern
SC
Threatened
TH
Endangered
EN
Extirpated
EX

SARA Status

  • No Status NS
  • Special Concern SC
  • Threatened TH
  • Endangered EN
  • Extirpated EX
COSEWIC Status
Not at Risk
NR
Special Concern
SC
Threatened
TH
Endangered
EN
Extirpated
EX

COSEWIC Status

  • Not at Risk NR
  • Special Concern SC
  • Threatened TH
  • Endangered EN
  • Extirpated EX

Description

The copper redhorse is the only fish living exclusively in Quebec. Weighing more than 5 kg and with a length generally greater than 50 cm, it is the largest of Quebec’s redhorses. It also lives the longest, reaching thirty years of age. This copper tinted fish with large scales has robust teeth, particularly well adapted to crush the shells of its preys. Copper redhorse population size estimates remain uncertain, numbering them at the most a few hundred individuals.

Habitat

The copper redhorse lives in shallow grass-beds around the islands in the St. Lawrence River and its lakes. These grass-beds provide plenty of gastropods, which represent 90% of the copper redhorse’s food resources.

Known spawning grounds are located in the Richelieu River, below the Saint-Ours dam and in the Chambly rapids. After hatching, the copper redhorse fry will find shelter and food in the grass-beds along the river.

Threats

Many studies carried out since the early 1990s demonstrate that the copper redhorse has difficulties reproducing naturally and that the population is aging.

This species’ habitat is under great pressure from agriculture, urbanisation and recreational activities. Habitat degradation is related to the majority of the threats to the recovery of the copper redhorse. This degradation can be caused by erosion and increased suspended matter owing to agriculture, deforestation and urbanisation, by contamination of water with pollutants disrupting the reproduction process, and by the premature aging of the rivers. Dams that fragment habitat and represent obstacles to migration, decreased water levels and disturbance by boaters and anglers are other threats to the copper redhorse.

Furthermore, several characteristics of the species’ biology and ecology increase its vulnerability. For example, spawning activity takes place late in the season, exposing the copper redhorse to lower water levels and a shorter growing season for fry which are consequently smaller in size when facing their first winter. The spawning period of the copper redhorse also coincides with the pesticide application period and therefore to peaks in concentrations of these pollutants in rivers.

Further Information

The copper redhorse is listed an endangered species and is protected by the Species at Risk Act since 2007. A recovery team developed a recovery strategy, which was published in 2012 by Fisheries and Oceans Canada. Since 1995, three five-year intervention plans, developed by the Government of Quebec, helped acquire data on the basic biology of the species and the threats affecting it.

Several actions have been taken to promote the recovery of the copper redhorse. The Vianney-Legendre fish ladder was constructed in 2001 so that the copper redhorse can move up the Richelieu River to spawning grounds in the Chambly rapids. This fish ladder is operated by Parks Canada. The Chambly rapids spawning grounds are protected by the Pierre-Étienne-Fortin Wildlife Preserve, created in 2002 by the Ministère des Ressources naturelles et de la Faune du Québec in order to ensure a peaceful reproduction period. An awareness campaign is also taking place in the Wildlife Preserve, in order to educate boaters and the public about the copper redhorse. This campaign, carried out by the Comité de concertation et de valorisation du bassin versant de la rivière Richelieu, is financed in part by the Habitat Stewardship Program for Species at Risk.

In order to compensate for the weak natural reproduction, an artificial reproduction and stocking plan has been implemented since 2004 by the Ministère des Ressources naturelles et de la Faune du Québec in collaboration with Fisheries and Oceans Canada. Close to three million larvae and 140,000 juveniles were released in rearing grounds along the Richelieu River between 2004 and 2009.

Visit the Species at Risk (SARA) Public Registry Profile.

Copper Redhorse

Copper Redhorse

Photo: Nathalie Vachon, Ministère des Ressources naturelles et de la Faune du Québec

Scientific name: Moxostoma hubbsi
SARA Status: Endangered (December 2007)
COSEWIC Status: Endangered (November 2004)
Region: Quebec

Copper redhorse distribution area

The distribution range of the copper redhorse is restricted to the St. Lawrence River, from Lake Saint-Louis to Lake Saint-Pierre, and to the Milles Îles, des Prairies and Richelieu rivers.
Gilles Fortin, DFO

Did You Know?

The copper redhorse is the only fish species with a distribution range entirely in Quebec. It is found nowhere else in the world.

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