Isotope analyses of the lake sediments in the Plitvice Lakes, Croatia

A marked increase in radioactive isotope 14C activity in the top 10–12 cm of sediment cores from Plitvice Lakes' karst lakes Prošće and Kozjak reflects atmospheric nuclear testing during the 1960s. This finding, derived from accelerator mass spectrometry and low-level gamma spectrometry, also revealed anthropogenic 137Cs in sediments. Sedimentation rates were estimated using unsupported 210Pb activity, while stable isotope 13C analysis differentiated geochemical and biological processes affecting carbonate (63–80 pMC) and organic (82–93 pMC) fractions. Comparisons with earlier sediment samples (1989, 2003) highlighted shifts in carbon isotope composition, underscoring the lakes' sensitivity to both natural and anthropogenic influences.

Horvatinčić, N., Sironić, A., Barešić, J., Bronić, I., Nikolov, J., Todorović, N., Hansman, J., & Krmar, M. (2014). Isotope analyses of the lake sediments in the Plitvice Lakes, Croatia. Open Physics, 12(10), 707–713. https://doi.org/10.2478/s11534-014-0490-7