This is D-U-M-B, dumb. This is not going to solve anything. It's just a cruel act that's going to have an adverse affect on our ecosystem. You can't kill all the birds, and to even try is dumb.
Actually, it isn't dumb. It's really well know that entirely removing a breeding population of geese from an area is an effective method of control - geese are relatively slow to recolonise areas, even when population pressures on other sites will be great - they use the fill to high density and then overspill approach to colonisation.
Goose control around airports can be pretty simple to manage as a result. Find out where your birds are flying to and from, find out where those birds are breeding, and cull at the breeding site. Voila, reduction in risk from flying birds. You are not trying to kill all the birds - you are trying to remove those which are causing the greatest risk. Such programmes can be highly effective - but they are not often publicised outside the birdstrike prevention community because of the reactions of those that assume that birds are more important than people and that any killing of birds is therefore bad.
Additionally, the birds being removed are likely to be from the Atlantic Flyway Canada Goose population. I'm struggling to see how removing birds from that particular popuulation would have an adverse effect on the ecosystem - that particular population has growth rates (last time I checked) in excess of 10%. So localised population removal is not going to affect the population - except possibly to reduce the grown rate. The population itself, due to its vast increase in size (which incidentally was one of the reasons for the increase in certification standards for the engines of the A380), is causing significant ecological damage and degradation on a number of places, since high density breeding is very detrimental to water quality, vegetation, marginal vegetation of ponds etc etc etc. Reducing numbers in some areas is likely to be good for the ecosystem.