Aquatic macrophytes as indicators of heavy metal pollution of water in DTD canal system

Abstract

The aim of this investigation was to establish the presence or absence of chemical contamination of water and the littoral zone (banks) of Danube-Tisza-Danube (DTD) canal system. The investigation covered the canal section from Bezdan to Prigrevica. By analyzing the chemical composition of dominant aquatic species in four locations of the section, we defined the species with the highest capacity to accumulate nutrients and heavy metals. Concentrations of P and K as well as of a beneficial element Na in the tissues of the analyzed macrophytes were both species- and site-dependent. The highest accumulation was registered for Ceratophyllum demersum while the species Elodea canadensis showed increased P and K accumulation values in the location Sombor. The lowest concentrations of almost all heavy metals were recorded near Sombor, indicating that this section suffered the lowest chemical pollution. Highest concentrations of all of the analyzed heavy metals were recorded in the tissue of Ceratophyllum demersum from the location Prigrevica, possibly due to the influx of polluted drainage waters from surrounding agricultural areas as well as industrial wastewaters. The obtained results showed that the enforcement of biomonitoring and analyses of other parameters indicative of ecosystem conditions might be useful for improved protection of areas experiencing a strong human impact.Koncentracije makroelemenata P i K, kao i korisnog elementa Na u tkivu ispitivanih makrofita zavisile su od vrste i lokaliteta. Najveci akumulator je bila vrsta Ceratophyllum demersum, a na lokalitetu Sombor po vecoj akumulaciji P i K izdvojila se i vrsta Elodea canadensis, sto ukazuje na organsko opterecenje vode. U poredjenju sa ostalim lokalitetima, koncentracije gotovo svih teskih metala u makrofitama lokaliteta Sombor bile su najnize, te se na osnovu toga ovaj lokalitet moze smatrati najmanje ugrozenim hemijskim polutantima. Najveci akumulator teskih metala bila je subterzna vrsta Ceratophyllum demersum. Na lokalitetu Prigrevica u tkivu vrste Ceratophyllum demersum registrovane su najvece koncentracije svih ispitivanih teskih metala. Visoke koncentracije teskih metala u makrofitama ukazuju na hemijsko zagadjenje kanalske vode na ovoj deonici, sto moze biti posledica ulivanja zagadjene drenazne vode sa okolnog poljoprivrednog podrucja, kao i industrijskih otpadnih voda. Dobijeni rezultati jasno ukazuju da bi se planskim pracenjem (monitoringom) hemijskog sastava biljaka uzetih sa ugrozenih lokaliteta, uz analizu i drugih pokazatelja stanja ekosistema moglo brze i sveobuhvatnije doci do resenja problema zastite od zagadjenja podrucja pod velikim antropogenim uticajem.