The confluence of the St. Lawrence Estuary and the Saguenay River, where the waters of the Great Lakes, the Saguenay basin and the Atlantic Ocean meet, is recognized as an ecologically exceptional region.
The oceanographic conditions that occur at the confluence of the Saguenay encourage the emergence of life and the concentration of species at the bottom of the food chain.
The uneven underwater topography, the estuarine circulation and the regular upwelling of cold water make it a very distinctive region. The upwelling of cold water at the head of the Laurentian channel is the most important oceanographic process of the Marine Park. This phenomenon brings nutrients and zooplankton to the surface and encourages the water’s oxygenation. The upwelling of cold water following the rhythm of the tides somewhat acts as the heart and lungs of the Marine Park.
The abundance of food in the Marine Park’s ecosystems attracts many species of birds, whales and seals. As well, numerous types of algae, benthic animals and fish have been observed in the Marine Park. Together, these species form a complex food chain supporting the significant biodiversity present in the Marine Park.