Lovely soft light and colours. I might take a tiny bit off the left and bottom to move the duck a little to the left and lower in the image. A little more DOF would have been nice. Looks like 2 dust spots on the sensor in the foreground that would clone out easily. Very nice shot.
I agree with Tony about the composition, but I do not mind the DOF...it is sharp where it needs to be. I really like the pale pastel blues here. If at all possible I would have liked to have seen a lower angle - perhaps being flat on your stomach instead of on one knee :-)
There's plenty of sharpness for me and I like the pose also. To my eye the water is too bright and the bird too dark. Here's a repost that tries to balance things out a little.