Thermotolerant coliform counts and nutrient levels as indicators of water quality in sub-Mediterranean karst river

Neretva is a karst river in Southeastern Bosnia and Herzegovina and the largest tributary of the Adriatic Sea in the Balkans. Its basin is hydrologically specific, with remarkably developed ground and underground water systems. In its upper catchments Neretva is a typically alpine, pristine river, with the spring located deep in Dinaric Alps at an altitude of 1 227 m. The main feature of Neretva’s middle catchments are the breathtaking canyons with limestone cliffs up to 1 200 m high, estimated to be more than 175 million years old[1]. In the lower catchment areas, Neretva with its complex hydrography and influence of the Adriatic Sea turns into a wide and slow lowland river. Its exceptionally rich alluvial meandering delta is enlisted as a Ramsar site of an international significance. Biological diversity is a main characteristic and quality of this region. There is a large number of life forms and communities with a high degree of complexity and biogeographical significance, due to varied climatic impacts along horizontal and vertical profiles of the basin, which vary in altitude for over 1 000 m. High mountains of the basin preserve numerous arctic and alpine relicts, which were distributed throughout Dinaric Alps during the ice age[2]. Within the researched area of the basin, sub-Mediterranean influence and different potamological factors contribute to development of thousands of plant and animal species with a high degree of endemism. A significant natural attribute of the region are pristine spring waters.