Quebec underwater structure found in Bing Maps?

I am just confused on what really this structure that I found while playfully browsing the updated Bing maps. I found what looks like an underwater structure near the Pont Pierre-Laporte bridge in Quebec, Canada.

Bing image of the location of the monstrous structure (encircled):
I tried to look for it using Google Earth but could not find it.
Can anyone shed a light on what this structure really is? Below is the zoomed image. What is that? That doesn't look like a shadow to me.