Eco.mont Vol. 9 Nr. 1, pp. 15-21, 2017/01/13
Journal on Protected Mountain Areas Research and Management
The Jiu River within its gorge was for a long time a river without fish due to pollution from the coal mines in the Petroşani basin, situated upstream. Currently, the river is threatened by the development of hydroenergetic installations, which are projected to reduce the river flow drastically. As a result of the project, less than 10% of the river flow will remain in the gorge. In the summer of 2015, we studied the composition of the fish fauna in Jiu River Gorge. We found 11 fish species, of which 10 are native to Romania and characteristic for the region and of the habitats studied. Only Lepomis gibbosus is invasive; it was identified in one tributary, with fast flow and rocky substrate, where it was probably introduced. The fish fauna from the Jiu River is uniform due to the region’s and river’s uniformity. Typically, mountain species are rare and present only in the upstream tributaries. The high anthropogenic influence in the southern part of the gorge, the presence of a less-affected area in its centre, and the mountain species found exclusively in the upstream zones are observed in relation both to fish and to other groups. Despite decades of coal mining pollution, the Jiu River now has a fish fauna that corresponds to the region and its habitats.
Keywords: mountain river, human impact, colonization, uniformity, mountain species, invasive species
