The first study launched by the Éolien en Mer SIG in 2021 involved the monitoring of breeding gulls at five natural sites: Bracquemont, Berneval, Belleville, Cap Fagnet and Cap d’Antifer.

Examination of the change in the census of these colonies shows a sharp decrease in the number of breeding pairs since the end of the 1990s. This decrease can be linked to several factors including disturbance, predation, interspecific competition and the disappearance of shingle banks at cliff bases.

In 2021, the virtual absence of nests at the base of the cliffs made it impossible to start ringing gulls. The production of young, i.e. the average number of chicks per nest, is poor to average depending on the colony.

In light of the results for 2021, the Scientific Council of the SIG has modified the monitoring protocol. The census and monitoring of production will continue for these five colonies so that the trend in numbers and environmental quality can be evaluated. Ringing will be carried out on the Le Havre urban colony.