After six months of work, master's intern Charlotte Mallard is completing a study on the sensitivity of coastal birds to disturbance on Thau Lagoon. The objective is to better understand the effects of leisure activities on nesting birds, especially in the Tocs de Thau and the former salt pans of the lido, where areas frequented by wildlife and humans overlap.
The study utilized the national BirDistance protocol, developed with the Centre d’écologie et des sciences de la conservation (CESCO) of the National Museum of Natural History. This protocol, piloted in 2025 in Brittany and deployed in 2026 on several French pilot sites under the European LIFE Mobile Marine Species program, measures the distances at which birds react to human presence.
Not all bird species have the same sensitivity. To preserve their tranquility, a protection distance of 180 meters around sensitive areas has been established, considering the most vulnerable species at Tocs. This threshold aims to limit disturbance and ensure favorable conditions for their reproduction.
Cross-referencing data on human activity and bird presence has identified areas where coexistence is most challenging. The Tocs de Thau, a favorable habitat year-round, sees some breeding areas heavily frequented in spring and summer, which can hinder colony establishment. The study suggests extending the current tranquility zone eastward to provide more space for birds, while minimizing constraints on water sports and boating activities concentrated around the Pont-Levis.
This concrete data aims to reconcile biodiversity preservation with leisure practices on Thau Lagoon. Facing the decline of marine bird populations since the 1980s, limiting disturbance, especially during the breeding season, is a major challenge. The classification of the lagoon as a Natura 2000 site underscores the importance of these areas for wildlife and the resulting collective responsibility.
