Birds on a land based airfield can be discouraged by keeping the grass at the rght length. They don't seem to like six inch high grass as they can't see predators arriving. I don't believe the same precautions would be available over wetlands.
Far from being a NIMBY's or "Greens" reason to oppose the development, I would contend that it is a real obstacle, not one invented to scupper the airport. Wetland birds also tend to be bigger and heavier than the main inland varieties. Hit a sparrow, starling etc you will probably get away with it, I wouldn't have the same confidence after hitting a Greylag or Canadian goose.