My initial thoughts:
First row, left: this is not too bad, but you have placed the horizon right in the middle of the picture. This is generally considered not the best placement. Check out rule of thirds and horizons. It is unfortunate that there are no clouds higher in the sky, but we often have to take what we can get.
First row, right: again, not a bad picture, but you cut the bird in half with the horizon. I would try to either lower or raise the horizon so it is not doing this. I would also clone out the two bits of distracting boats(?) in the background. Also, you have the bird in the centre of the picture, I am not sure how much you have cropped this one, but the usual approach, again the rule of thirds, is to place the bird on the right or left third looking into the other two thirds of the image.
Bottom, left: there is too much distraction in the background and again, the bird is right in the centre of the picture. In this case, with the bird looking to the right, I would have moved it a bit to the left third line of the image.
Hope this helps.
WesternGuy