Winter field sampling (fishes)
Winter field sampling of fishes, water and sediment was conducted from 9th to 14th March 2026.
At five sites (Sveti Martin na Muri, Mursko Središće, Podturen, Goričan, Kotoriba) we have collected the following samples and performed the following measurements:
1. water for the measurement of dissolved metals (traces, macro elements, and rare earth elements)
2. water for determination of hardness and turbidity
3. water for measurement of organic contaminants (pesticides, antibiotics)
4. water for determination of environmental DNA (eDNA)
5. sediments for measurement of metals in two fractions (<2 mm, <0,63 mm) and organic matter content, and for grain-size distribution analyses
6. sediments for determination of bacterial metal resistance genes
7. several physico-chemical parameters were measured (water temperature, pH, conductivity, and dissolved oxygen).
At three sites (Sveti Martin na Muri, Mursko Središće, Goričan) we have collected the following samples and performed the following measurements:
1. two fish species: chub (Squalius cephalus) and barbel (Barbus barbus)
2. blood: for measurement of 21 biochemical biomarkers in serum, determination of hematocrit from whole blood, and analyses of micronucleus and nuclear abnormalities in blood smears
3. liver and gonads: for measurements of bioaccumulated metals (total, cytosolic), determination of metal nanoparticles, analyses of tissue biomarkers, analyses of metalloproteins
4. muscle: for measurement of bioaccumulated metals (total) and risk assessment for humans occurring from dietary ingestion, for determination of metal nanoparticles
5. fin and scales: for 2D-determination of metal distribution using micro-XRF
6. scales: for determination of fish age
7. determination of fish biodiversity was done by classic approach based on fish morphology.
