Lavallière Bay is a managed marsh with a surface area of 21km2located behind Sainte-Anne-de-Sorel at the confluence of the Yamaska and St. Lawrence Rivers. This marsh was primarily set up to conserve waterfowl and has also become a spawning ground for fish. Frogs also live here. When we began our studies, our inventories were only intended to target breeding grounds. Over the years, with everything that has occurred, we observed that these sites have become important. They are the last places where these species can reproduce. Suitable environments for species are disappearing at an alarming rate. These environments are worth preserving, so we have been placing greater emphasis on our inventories.
The Northern Leopard Frog is the main species that lives, breeds and hibernates in Lavallière Bay. They are extremely abundant in the bay. In the spring, you can hear thousands of frogs singing. There are also some Bullfrogs and Green Frogs. Closer to Saint-Robert and Yamaska, we also see Spring Peepers and Wood Frogs. There have been a few studies of Lake Saint-Pierre. Why Lake Saint-Pierre? Because several tributaries flow into it: the Saint-François, the Yamaska, which is one of the most polluted, and the Richelieu. Why carry out studies in Lake Saint-Pierre? We realized that there was a possibility that pesticides were causing deformities. We carried out a 2-year study. Over that two-year period, we tried to find deformed frogs, but were unable to find any. This is an issue we will need to follow up on... We have also studied Common Mudpuppies to see if they could serve as a bioindicator for the St. Lawrence River. We caught a few individuals and took blood samples to check for contamination. This study took place in 1995. We caught a certain number of mudpuppies and dissected them. This is how we saw that they could be used as bioindicators. They were contaminated with pesticides and heavy metals.
I would say the most common reptile in Lavallière Bay is the Snapping Turtle. The next most common is the Painted Turtle. Recently, we have observed Map Turtles in the bay. This is a new development. The Red-Eared Slider is the little turtle you find in pet shops, with the red ears. They can be found in Lavallière Bay. There is no evidence that they are breeding, but we have observed a few individuals. People buy these turtles in pet shops. When they grow too big, they release them in Lavallière Bay. They can survive our winters. These turtles can be very aggressive when it comes to their breeding areas. This could be dangerous for the Painted Turtle, which is closely related to the Red-Eared Slider.
The Société d’aménagement de la baie Lavallière’s work mainly involves technical support. We bring them to the site, they tell us what they want and we carry out the work. If necessary, we catch a certain number of frogs and measure contamination levels, and so on. We have also been monitoring ducks. We capture them and band them to study bird flu. These studies are also useful in establishing hunting quotas. We are studying fish with the Quebec government, to find ways to make it easier for them to enter the marshes because fish have a lot of trouble in flooded areas. So we are working on that as well. We are also studying invasive plants and making inventories of them throughout Lake Saint-Pierre.
