James, nice image, the seal does indeed blend into the rocks, this illustrates that nicely. This looks to have been taken from an elevated vantage (the seawall in La Jolla?) If so, you did well, it is more difficult to get a pleasing image from up high and this one works well. My only suggestion is to consider sharpening the detail in the face a bit so the whiskers and eyes snap.
A very interesting environment to photograph this seal in....well spotted. IMO this would have been an even stronger image if your would have shown more of this rocky environmen though.