Assessment of anthropogenic, seasonal and aquatic vegetation effects on the contamination level of oxbows

Abstract

The contamination level of oxbows depends on both natural and anthropogenic effects. The aim of our study was to identify those abiotic and biotic factors that determine the contamination level of oxbows. The effect of anthropogenic activities, seasonality, and vegetation types was studied on the contamination level of surface water of oxbows. The following chemical variables were measured: suspended solid, ammonium, nitrate, chlorophyll-a, Al, Ba, Fe, Mn, Pb, Sr and Zn from eight oxbows from 2013 summer to 2014 autumn in the Upper Tisza region in Eastern Hungary. Three of the studied oxbows were protected, four oxbows were used for fishing and one oxbow was contaminated with wastewater. Our findings revealed that anthropogenic activities had remarkable effect on the contamination level of oxbows. Seasonality also influenced the contamination level, except the concentration of suspended solid, chlorophyll-a and manganese. Significant differences were found among vegetation types for the concentration of suspended solids, aluminium, iron, manganese and lead. The high level of iron concentration was not explained by the anthropogenic activities, suggesting that the quality of oxbows depends on both natural and anthropogenic effects.