I am always interested when the word "seagull" is used as it is covers so many species.
We get Common gull and black-headed gulls here all the year round with occasional visits from Greater and Lesser black-backed gulls and some Herring gulls. And this is at least 30 miles from the sea! It gets very confusing as they vary in plumage so much between juveniles and adults.
I think the supermarket tomatoes are actually getting worse over the years.

Robin