The Lower Estuary : a special habitat 

The Atlantic Ocean, approximately 4830 km wide and 4000 m deep, is a limitless whale playground. Nevertheless, every spring, hundreds of cetaceans turn tail on this vast environment, cross the Gulf of St. Lawrence and move up the Estuary to the mouth of the Saguenay. At this juncture, a scant 25 km separates shores where the water is at best 300 m deep. Whales are thousands of kilometres from their mating grounds. 

Why do they undertake such a lengthy expedition? Because the St. Lawrence Estuary is teeming with fish and plankton. Feeding becomes their main activity: summer slips away very quickly, every mouthful counts, they have to fill up!

This habitat is also the heart of the beluga whale’s summer range. St. Lawrence beluga whales, by definition, spend their entire lives in this waterway.

A plankton trap

Currents, tides and the sub-aquatic lie of the land conspire to accumulate food in specific areas that the whales know very well.

Fronts, tide rips and vortexes

The confluence of the Saguenay and the St. Lawrence rivers.

Tides

Understanding tides, in the Estuary and elsewhere.