The contrast in color between the ground and the sky, the visual elements that start with the wood in the foreground and leads your eye up through the picture all the way to the trail of birds in the sky. There are a lot of elements of interest in this photo for me and they all mesh together well.
The only question I have is that the image seems a little soft to me. Could just be the monitor I'm using, but it feels like things should be just a touch sharper.
Great composition... broken lines, wonderful contrast in colors and hues, birds... oh those birds, how perfect... you are blessed to have been able to capture that picture, now go sell it and make some money!!!
1) good job on getting the sky exposed properly.
2) birds are in perfect position... gives a sense of direction
3) people and houses provide the scale
4) the garbage is cool too... otherwise it'd be boring
5) the blue deposits on the sand are cool too... means some metal is present there... forgot which.