Invasive alien species pose severe threats to global biodiversity, ecosystem functions, and socio-economic values, particularly in coastal and marine ecosystems. This study aimed to investigate the trophic interactions between alien species and native fauna in a Mediterranean coastal ecosystem. Notably, our research focused on the presence and ecological roles of the invasive Atlantic blue crab (Callinectes sapidus) and the brown shrimp (Penaeus aztecus) within the Vendicari Nature Reserve (VNR), a protected area on the southeastern coast of Sicily, Italy. Field observations, specimen collection, and interviews with local fishermen were conducted to assess the presence, distribution, and feeding habits of these species. The results revealed significant temporal shifts in the diet of C. sapidus, with a clear decrease in predation on the alien Penaeus aztecus (first observed in the VNR) over the study months. The presence of C. sapidus in the fishing area around the reserve has been detected for many years, while P. aztecus appears to have recently colonized the area. Additionally, photographic evidence documented the predation of C. sapidus by Octopus vulgaris, highlighting a potential adaptive feeding behavior by the common octopus in response to the abundance of this invasive crab. The integration of scientific research, local ecological knowledge, and community participation is essential for mitigating the impacts of biological invasions and preserving the biodiversity and ecological integrity of natural ecosystems.

Rocky habitats are suitable refuges for numerous rare and endemic plants. Due to their inaccessibility and the unreliability of traditional survey methods, assessing the survival status of these plants is quite a hard task. In order to address this sampling issue, we employed the drones and carried several field activities to investigate the vascular flora of Rocca di Novara massif located in Northeastern Sicily (NE Sicily hereafter). Located on the southern border of the Peloritani Mountains, Rocca di Novara, also known as Rocca Salvatesta, is a small carbonate massif and it represents one of the highest and most characteristic peaks in NE Sicily. According to our investigation, 300 taxa have been recorded, belonging to 189 genera and 51 different families. The results obtained show the presence of 13 endemic species to Italy (4.3%) and 12 strictly endemic to Sicily (4%). Some taxa of high phytogeographical value have been detected, such as Aubrieta columnae subsp. sicula, Daphne oleoides subsp. oleoides, Edraianthus graminifolius subsp. siculus, Fritillaria messanensis, Odontites bocconei subsp. bocconei, Phelipanche gussoneana, Saxifraga callosa subsp. australis. This latest species was rediscovered after 100 years on the high cliffs of Rocca di Novara thanks to the use of the drone imagery. Our results provide valuable insights into the floristic diversity of Rocca di Novara and offers a solid starting point for further phytogeographical and floristic studies on the vascular plants of the Peloritani district.