Here's another image from a couple of days ago in Sackville, New Brunswick. I have cleaned up the scummy water, reduced noise with Dfine and cropped pretty heavily. I'm not sure about the comp as the head is on the midline of the image. If I had more of a head turn to its left I could have placed the whole bird more to the left. With the bird looking more or less straight ahead I felt the need to give it some space in front. Comments welcome.
40D, 100-400mm @400mm, 1/1250s, F8, ISO 640, Av, from RAW.
I like the picture. I always find them a challenge to hold the whites. It looks like the sun was off to your right, leaving the breast in a bit of shadow. I would be tempted to crop it a bit differently if possible, moving the bird up or down a bit. I suspect the reflections above the bird might restrict moving the bird down more.