Toxicity Screening of Surface Waters in Zaghen Restoration Area with Toxkit Microbiotests

In this study, we report the findings regarding the toxicity of surface waters collected in March 2023 from five sampling stations in the Zaghen restoration area, located within the Danube Delta Biosphere Reserve, Romania. The assessment of acute toxicity was conducted using two microbiotests: the Thamnotoxkit F and the Daphtoxkit F^TM magna. Even if the acute toxicity effects are less than 50% and do not allow the calculation of a toxicity score for the water samples, the experiments show a different vulnerability of the two zooplanktonic species to the presence of heavy metals in the water with mortality being higher in Thamnocephalus platyurus (20%) than in Daphnia magna (15%).