engleski

Ecotoxic trace metals in waters of "Krka" National Park - Croatia

The Krka National Park is a large area of exceptional and multifaceted natural value, and includes one or more preserved or insignificantly altered ecosystems. It is situated entirely within the territory of Šibenik-Knin County and encompasses the area of 109 square kilometers along the Krka River. Its aquatic environment is mainly fresh water with nine tufa waterfalls and total drop of 242 meters. Therefore, the Krka River flow area is the nature and karstic phenomenon. Limestone deposits from dissolved calcium bicarbonate form tufa barriers creating waterfalls. The tufa depositing is a constant and dynamic process, including physiochemical factors and organisms present in described water ecosystem. As protected natural areas of the Krka National Park is very sensitive ecosystems because of their substantial uniqueness it should be preserved in their original form. Spatial and temporal distributions of five ecotoxic trace metals (Cd, Cu, Pb, Zn and Hg) in waters of “ Krka” National park sampled during 2004, 2005 and 2006, were studied to assess actual ecotoxic trace metals concentration levels. Cd, Cu, Pb and Zn concentrations are measured as dissolved (filtered) and total (non-filtered). Elevated trace metal concentration levels in such vulnerable systems could be a sensitive indicator for possible anthropogenic influence. In these nature compartments of the Krka National Park any anthropogenic influence or input is serious risk for biodiversity. Therefore, regular monitoring (periodic, field/laboratory) is necessary to distinguish elevated trace metal concentrations naturally present in the particular aquatic environment from the anthropogenic introduced ones. Obtained results suggest complex behavior of different trace metals species investigated in the River Krka waters from the Krka spring to the Skradinski Buk waterfalls. Interesting locations are emphasized: subterranean input of clean water near Miljacka power plant and surrounding caves, and anthropogenic influence of communal waters downstream of city of Knin. Range in trace metals concentrations in Krka River water were: Zn dissolved from 59 to 3890 ngL-1 and total from 83 to 9410 ngL-1 ; Cu dissolved from 20.0 to 1300.0 ngL-1 and total from 58.5 to 5898.0 ngL- 1 ; Pb dissolved from 3.4 to 29.6 ngL-1 and total from 8.2 to 275.7 ngL-1 ; Cd dissolved from 0.5 to 7.14 ngL-1 and total from 1.0 to 8.4 ngL-1 ; Hg total from 0.5 to 16.0 ngL-1.

trace metals; ecotoxity; Krka River

nije evidentirano