The growing interest in emerging environmental crisis has increased the level of public attention and the willingness to take part in participatory science projects, commonly defined with the term “Citizen Science”. This phenomenon can be recorded globally in many national contexts, with a prevalence in anglophone and more industrialized countries. In the biodiversity sector, the growing demand for public involvement has been declined in many different ways, with solutions aimed at providing cognitive and participatory tools. Among these, one of the best known is the BioBlitz: a 24-hour event held in a specific place with the aim of listing as many living species as possible. This work presents the data collected during the first two BioBlitzes organized by the Maremma Natural History Museum in 2013 and 2014. Both were made in the area of the San Felice Oasis, near the terminal part of the San Leopoldo ditch. During the BioBlitz, data collected attested the presence of 627 different taxonomic entities, of which 527 were identified at the level of species and 12 at the level of subspecies. The rest were identified at higher taxonomic levels. Eleven alien species, one endemic species, 33 species protected by national and international laws and / or directives and 13 species at risk of extinction were identified.
