We have a huuuge seagull problem here in Gloucester, one of the worst in the country
The problem is they are not allowed to cull them, and other containment methods such as oiling eggs have failed
We have docks here, and water, so that brings them but the main problem is a massive tip on the edge of town. They come into the city centre and are very aggressive in their pursuit of food, often swoop and attack, and also rip open rubbish bags which contributes to the run down look of parts of the city. They mess on people too, it has happened to me once or twice. I now walk down the middle of the pedestrian streets, because if you walk close to the edge of the buildings you will likely get messed on
They are very big, with wingspans of several feet, and quite scary