I agree totally about expanding the regional airports - and whilst at it, enforcing clearway rules.
But, at risk of seeming ignorant, would building an airport in the centre of the Isle of Grain really have that huge an effect on the bird populations in the Medway and Thames estuaries? So far as I can see, the airport wouldn't actually impact on the areas I'm used to seeing all the bird population, and the airliners would be at 1500ft+ as they went overhead, well above normal seabird operating heights? I'm sure it would become noisy and unpleasant for people, but the birds?
Please don't get upset with me for saying that, I really don't know the answer and it seems a fair question to ask.
G
N.B. Have you read Rockets Galore by Compton Mackenzie, which has a great bearing on the case.