The Canadian Rivers Institute, based at the University of New Brunswick and N.B. Power, has released findings from a 2025 bio-monitoring program.
During the 2025 field season, 81 locations were surveyed. A total of 22 adult zebra mussels were documented at only three locations. Of the documented mussels, 21 were found at hydroelectric generating stations (19 found at Mactaquac Generating Station, two found at Beechwood Generating Station).
The CRI says no zebra mussels were found at Tobique Narrows Generation Station or Grand Falls Generation Station.
The other zebra mussel was located at where Belleisle Bay and the Wolastoq meet, marking the CRI’s furthest downstream discovery.
“The current low-level colonization provides an important opportunity to take informed, proactive steps to better mitigate negative impacts to infrastructure and reduce the risk of spread to other waters in New Brunswick,” said Canadian Rivers Institute’s Dr. Meghann Bruce.
Zebra mussels are freshwater hinged mollusks that are invasive to Canadian waters. They are native to the Black and Caspian seas region in southeastern Europe. According to Fisheries and Oceans Canada, zebra mussels entered the Great Lakes in the late 1980s through ballast water emptied from ships. They have spread through eastern Canada and the United States since then.
These mussels are capable of rapid population growth and infrastructure fouling. This could mean damage to dams and other related forms of hydroelectric infrastructure, as well as changes to food webs, fish spawning areas, interference with native mussels, and other ecological impacts.
The CRI says ongoing monitoring is aimed at understanding what colonization could look like for New Brunswick’s freshwater systems. 2025 results show that although the invasive species is establishing itself on infrastructures, the Wolastoq / Saint John River is not yet experiencing widespread colonization.
To see the full release from the Canadian Rivers Institute, click here.
To see Fisheries and Oceans Canada’s research on Zebra mussels, click here.
