At least two live specimens of Asian carp have been identified in the Richelieu River, which concerns the Quebec Ministry of the Environment, as these fish represent a threat to the ecosystems of the waterways they inhabit. The United States has struggled with this family of invasive species for years.
Both Grass carp Found in the Vianney-Legendre fishery, located on the Saint-Ours Dam, on the Richelieu River. The Ministry of Environment, Climate Change, Wildlife and Parks (MELCCFP) hopes to catch the grass carp “to try to analyze them and confirm their provenance”.
“Their rapid growth, voracious appetite and diet of aquatic plants can severely damage grass carp habitat, disrupt the functioning of aquatic ecosystems and affect water quality,” explains the MELCCFP. In a press release Announcing the scenes.
“Even without establishing a long-term population, grass carp can cause significant damage to aquatic grass beds on which many native fish species rely for food or reproduction,” the ministry added. In the case of the Richelieu River, the situation is even more alarming because the “endangered” local species, the copper red horse, lives there.
Fish and DNA
The two fish found in the Richelieu River are the third and fourth grass carp recorded alive in Quebec since 2016. That year, a fisherman caught 27 kg of carp in Contrigoeur. A second grass carp was caught by a sport fisherman in the Chambly Basin in July 2020. This species can reach over a meter in length and weigh over 50 kg at maturity.
In addition, several positive detections of bull carp environmental DNA in the Richelieu River have been documented by the MELCCFP since 2017. Positive samples were collected in the mouth of the Rivière des Prairies, east of Montreal Island, and in the Saint-Pierre Archipelago and lake.
Asian carp were imported to the United States in the 1970s for aquaculture purposes. Thanks to the flood, they were able to reach the Mississippi River, then go up the mythical river and occupy the waterways connected to it for more than 1,500 kilometers.
Grass carp, one of the four species of Asian carp, is already well represented in the Great Lakes connected to the St. Lawrence River. Also, breeding of the species has been confirmed in two rivers flowing into Lake Erie.
According to Fisheries and Oceans Canada, if the species becomes established in the Great Lakes, it can “harm native species, almost completely eliminate aquatic vegetation” and “detriment” the habitat of bird species.
