“Marini da Nord”: monitoring changes in abundance and distribution of Atlantic seabirds wintering in Italian seas using a Citizen Science approach

The Mediterranean basin is a hotspot of biodiversity and a region that is particularly subject to current climate change effects, such as increasing surface water temperatures and extreme events. Seabirds represent a target group to investigate how species can respond to such rapid climate and environmental changes, being tightly linked to the sea. In addition to local species, less common bird species typical of the North Atlantic, may migrate extremely southward and end up to winter in the Mediterranean waters, where they can be occasionally observed and reported. In recent years, unusual observations and anomalous irruption phenomena were recorded precisely in this area. However, to date, there is very little information on the distribution, abundance and temporal trends of these species for the central Mediterranean. Here we present a new project, “Marini da Nord”, that takes advantage of data collected by ornithologists and uploaded on the online platform Ornitho.it, in order to monitor the spatio-temporal changes in the abundance and distribution of 23 North Atlantic seabird species that winter in the Italian seas. The continuously growing dataset currently includes over 41,700 records spanning a 58-year period, from 1966 to the present. The dataset will continue to expand with future observations and may incorporate data from other Citizen Science platforms, as well as photos and videos shared on social media. We present the results of the first exploratory analyses on the dataset and comment on future developments for investigating how the most recent changes in climate and variations in the availability/accessibility of trophic resources could cause oscillations in the abundance and phenology of these species. The final objective of this pilot project is to develop a better understanding of the distribution dynamics of these species in the Mediterranean and to identify the environmental factors that determine them, ultimately affecting seabirds’ survival and population dynamics. Finally, we emphasize the crucial role of open social platforms and data sharing, such as Ornitho.it, in enhancing species detection and abundance estimation, reporting uncommon observations on a wide scale and in real-time, and preserving historical data for temporal analyses.