MODIFICATION OF THE FRESHWATER FISH COMMUNITY IN THE NATURE RESERVE "OASI DEL SIMETO" (SICILY-ITALY): PRELIMINARY DATA

ANTONINO DUCHI , Roberto De Pietro

There are no recent data on the fish fauna of Simeto, the river with the largest catchment area in Sicily. Based on this assumption, it is particularly interesting to search whether the fish community has suffered variations over the years or remained unaltered.A recent preliminary sampling investigation was carried out in the stretch of river flowing through the Natural Reserve "Oasi del Simeto", immediately upstream the Passo Martino small dam, at about 7 km north the river mouth. This sampling activity showed the presence of alien species, not previously reported in the area, including: Sarmarutilus rubilio, Cyprinus carpio, Carassius spp. Ameiurus melas, Gambusia holbrooki, Micropterus salmoides. There were identified no euryhaline species although past data displays positive findings on the upstream of the sampling area. The results show the symptoms of a significant shift in the fish species presence within this protected environment, which certainly deserves further study and, subsequently, interventions aimed at naturalistic requalification. In fact, this research brings first evidence on the impact of the Passo Martino small dam on fish fauna, particularly on euryhaline species, suggesting the removal of the small dam, which, among others, does not result to have a single tangible benefit.