Monitoring freshwater mussel density across Lake Massawippi
Zebra mussel implantation can also have a negative impact on a lake's native freshwater freshwater mussel populations (bivalves of the Unionidae family). freshwater mussel shells provide an ideal attachment surface for zebra mussels, which can attach themselves to them, competing directly for food and oxygen. In this way, zebra mussels can take their place in the ecosystem, creating local extinctions. However, the negative effects of zebra mussels on the environment of Lake Massawippi are minimal at present, allowing a long-term study to begin.
Table 1. Summary of freshwater mussel density monitoring results
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A freshwater mussel density monitoring project was developed in 2023 to assess the rate, magnitude and impacts of zebra mussel biofouling on freshwater mussel community health. The objectives are to characterize the density, diversity and physiology of lake freshwater mussel, and to compare and quantify variations in freshwater mussel that may be explained by long-term zebra mussel pressure.
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9 stations across the lake were surveyed using 1m² quadrats launched randomly at predetermined depths. The divers then collected the freshwater mussels found there. Physiological data were taken for each freshwater mussel before they were carefully returned to the ground.
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For the time being, our results show a low rate of zebra mussel colonization of freshwater mussels. The results of the coming years will enable us to measure the medium-term impact of zebra mussels on freshwater mussel populations, a first measure of the biological impact of zebra mussels in Lake Massawippi.
A trainee holding a quadrat used for density surveys in Lake Massawippi.
Figure 1. Map showing zebra mussel colonization rate by station. English map here.