Effects of waterfowl on water quality

The influence of waterfowl on the process of eutrophication in Balaton lake, Hungary, was investigated. Quantities of food consumed by cormorants (Phalacrocorax carbo) and 3 species of duck and quantities of waste excreted were estimated to quantify their role in the turnover of nutrients. Cormorants in the Kis-Balaton area, comprising 1500 pairs and their young, were estimated to take up 12.5 tonnes of nitrogen and 3.1 tonnes of phosphorus in 1983. The nutrient turnover of ducks was more difficult to quantify because their diet included plant material. Quantities of nutrients excreted were estimated to be lower than amounts consumed in food.