In my opinion it is technically pretty good. Your focus is superb. You've pulled more out of your kit lens than I have!
The crop is tough on this one, but i think you did it right. The background puts a good perspective on the overall feeling of the scene and the waves crashing over the rocks are nice icing. The gull is mostly on the right side of the frame, showing movement of the bird.
How was the lighting during the shot? It looks like it was a cloudy day. As such, the picture is a bit dark and muted.
