I don't see how you could crop it much without losing one of the nice features, and that is the neat reflection of the tree that runs all the way to the bottom of the image. If your not worried about that, I'd just do about a 50% landscape crop, with the goose at about the left 35 - 40% of the frame.
Thanks for the comments. I was thinking along the same lines as Jeff and Keith. Probably make it a 12x18 though. I am still kicking myself for not having at least a monopod with me. :x The light was great for a little while.