Other gull remedies you could try include:
Dead birds: used to signal danger to others
Propane Gas guns: produces a periodic loud explosion
Dogs: The birds temporarily find the area unattractive when the dog is there
Daddi Long Legs: patented seagull control system has a freely rotating head with long stainless steel wires that bounce in the wind or when birds contact it
Audible distress call: a recording of the distress call of the pest bird
Ultrasonics
Fracking: Bird charity, the RSPB, fear the method could disturb birds
Scarecrows: This method does not work so well with all birds, with some species frequently using them as a perch.