Spatial overlaps of foraging and resting areas of black-legged kittiwakes breeding in the English Channel with existing marine protected areas

The English Channel is one of the most anthropized marine ecosystems due to increasing human pressures, both along the coasts and at sea. Numerous marine protected areas (MPAs) have been created in this area but their ecological relevance still needs to be demonstrated for mobile species such as seabirds. Here, we identified the at-sea foraging and resting areas of black-legged kittiwakes to quantify their spatial overlap with existing neighbouring MPAs. Using solar-powered GPS-UHF, we tracked at-sea trips of 36 kittiwakes breeding at three colonies along the French coasts of the English Channel: Boulogne-sur-Mer (Hauts-de-France, n = 11), Fecamp (Normandy, n = 14) and Saint-Pierre-du-Mont (Normandy, n = 11). While kittiwakes nesting at the two Normand colonies shared some of their foraging areas, birds from Boulogne-sur-Mer did not overlap their foraging areas with Normand birds. GPS-tracked birds from all three colonies remained close to the shore (<30 km) and mainly remained within French national waters. The existing MPA network encompassed > 60% of all recorded locations, but MPA use was largely colony-specific. Habitat models built to predict habitat suitability confirmed that some MPAs encompassed highly suitable foraging and resting habitats for black-legged kittiwakes in the English Channel. Connectivity between the studied colonies was high, as indicated by inter-colony prospecting movements recorded in two individuals which supposedly failed their reproduction. Overall, this work highlights that marine species such as seabirds could benefit from existing MPAs. Nevertheless, the diversity of MPA types and their different roles complicates their effectiveness to protect marine biodiversity.