Occurrence of Non-Native Fishes in a Small Man-Made Lake (Lake Ula, Mugla): Past, Present, Future Perspectives

Abstract

Changes in fish fauna, fish conditions and some physico-chemical features of water of Lake Ula which was established for irrigation purposes and subjected to introduction of non-native fishes were investigated. Six different fish species were found, five of them belong to Cyprinidae family; common carp Cyprinus carpio L., 1758, gibel carp Carrassius gibelio (Bloch, 1782), goldfish Carassius ouratus (L., 1758), chub Squalius cephalus (L., 1758) and gizani Ladigesocypris ghigii (Gianferrari, 1927). The other species found was eastern mosguitofish Gambusia holbrooki Girard, 1859 from Poeciliidae family. Fulton's body condition values varied between 0.99 (chub) and 1.48 (gibel carp). Two Carassius species (non-native species) had significantly the higher condition values than those of other species(P<0.001). Comparison of condition data of chub and common carp from present study and published work in 1999 revealed no significant differences (t-test, P>0.05). Some physico-chemical features of water were compared and no big differences were detected between 1998 and 2009.