The content of chemical elements in Trаpa nаtans and Nymphoides peltata of the Volga Delta

   Aim. To identify the specific features of the accumulation of heavy metals in Trаpa nаtans and Nymphoides peltata in the Volga delta.   Materials and Methods. Plant sampling was carried out in the Astrakhan State Nature Biosphere Reserve. Determination of the concentration of chemical elements was carried out using atomic absorption spectrophotometry.   Results. As a result of the research it was noted that the plant species studied had some similarities in the accumulation of chemical elements. In both types of plants iron was predominantly accumulated, manganese content being in second place in terms of metal concentration. Chromium and cadmium were found to be in the lowest concentrations. Nymphoides peltata is an iron accumulator compared to Trapa natans. The leaves of Trapa natans are manganese concentrators, while the stems are copper concentrators.   Conclusions. Based on the specific features identified in the accumulation of chemical elements in plants, a proposal is put forward regarding the possibility of using the leaves and stems of Nymphoides peltata as a test object for monitoring iron and chromium concentrations in water and the leaves of Trapa natans for monitoring copper concentrations in water.