The unprecedented project of the Department of National Defense to remove thousands of shells from the bottom of Lake Saint-Pierre could cause the death of a million fish, in addition to having consequences on several species of birds. The federal ministry, which has used the body of water as a projectile test site for several decades, says however that all measures will be taken to reduce the effects of the planned detonations of more than 1,700 shells.
In September, the Legault government authorized the Department of National Defense (MDN) to withdraw nearly 15,000 shells lying in the bottom of Lake Saint-Pierre, where more than 500,000 shells were fired between 1952 and 1999. It is in particular planned to withdraw a little more than 9000 shells of high caliber, including 2739 which would be unexploded explosive ordnance (UXO) which can contain up to seven kilos of explosives.
Almost three weeks after the authorization of the project, the Ministry of the Environment and the Fight against Climate Change published the “expert opinions” of various ministries that analyzed the impact study produced by the DND.
We learn that experts from the Ministry of Forests, Wildlife and Parks (MFFP) assess that “despite the implementation of mitigation measures”, more than a million fish may be killed during detonations. , directly in the lake, shells too dangerous to be moved. According to a National Defense assessment, a total of 1,743 shells will have to be destroyed on site during the nine years of the project “to mitigate the risk to public safety related to unexploded explosive ordnance in Lake Saint-Pierre” . Of these, just over 700 are 155mm or 105mm caliber.
The MFFP specifies that more than 405,000 yellow perch could be killed during the detonations. The stocks of this species are in a “worrying state of health”, adds the ministry, which underlines that its evaluation of the mortalities of fish remains conservative.
Fragile ecosystem
Quebec government experts also point out that the ecosystem of Lake Saint-Pierre, which is recognized as a “biosphere reserve” by UNESCO, is increasingly weakened. “The state of health of the ecosystem is of great concern. It bears witness to the impact of human activities that have been taking place for decades in its watershed and floodplain ”, we can read in the opinion.
Professor in the Department of Environmental Sciences at the University of Quebec at Trois-Rivières (UQTR), Gilbert Cabana also emphasizes that Lake Saint-Pierre is affected by the impacts of intensive agriculture, but also of industrial waste and different contaminants.
In this context, he is concerned about the additional impacts that will result from the explosion of hundreds of shells, over a period of several years. “We are embarking on a major project,” he said. “If they detonate more than 1,700 bombs, it’s going to shake up a lot of things. It will therefore be important to monitor the impacts on fish from the start of the project. “
Mr. Cabana still welcomes the idea of removing this threat from the bottom of the lake. It must be said that the firing zone used by National Defense occupies an area of 160 km2 and that this zone is closed to access, in particular for researchers studying the ecosystem of the lake. “The presence of the bombs prevents us from going to work in this sector, because the threat is very real”, in particular because of the shallow water.
Same story with Vincent Fugère, professor of freshwater ecology at UQTR, who also believes that fish mortalities seem reasonable under the circumstances.
In addition to the some 80 species of fish found in Lake Saint-Pierre, this ecosystem serves as habitat for 288 species of resident and migratory birds. An opinion written by experts from Environment and Climate Change Canada also highlights “a significant risk” of “harmful” effects for migratory birds, if explosions occur in the spring or summer.
However, the Ministry of National Defense wants to be reassuring: the “detonation work” in the lake will only take place between September and December. With regard to the apprehended mortalities of a million fish, “mitigation measures” will be taken to “reduce” them. What is more, a compensation plan will be implemented. This will be used to reduce the predation of double-crested cormorants on the fish in the lake. As for the work, it will be subject to a renewed authorization on an annual basis.