Dipping the eggs in oil sterilises them - fooling the adults into thinking they are still viable. This means they sit longer on the nests on eggs that won't hatch.
More than 66 buildings were visited this year and for the first time a mobile mechanical hoist was used to access some of the more difficult sites.
Andrew Lewis, cabinet member for care and maintenance of the city, said: 'This has to be by far the most intensive gull mitigation work carried out in an urban area. As the adults do sometimes lay more eggs our staff visited each site two or even three times.
'Taking everything into account it is estimated that 719 chicks were prevented from hatching in the city centre this year. That's 719 chicks not causing a disturbance and 480 parents not getting protective and aggressive about their young'.
A bonus of the scheme is that the overall numbers in the city centre appear to be down this year - and is believed to be one of few documented examples of a reduction in an urban population. This compares to increases elsewhere in the city and in other colonies in the region.
It is thought that last year's unsuccessful females - those that had their eggs oiled - may have found other partners and nested elsewhere.