Ryszard Wojda, Grzegorz Zygmunt
ABSTRACT. The article present the results of investigations on the role traditional carp farms play in water retention and its quality improvement in small river drainage areas. Seven parameters were measured from March to October to calculate the budget between the amount of elements introduced into ponds and then removed at fish harvest: oxygenation, pH, temperature, BOD5, suspended solids, total phosphorous, and ammonia nitrogen in inflowing and outflowing waters. In the 2003-2005 period, water retention averaged approximately 31796 m3 ha-1. Only 37.5% was removed at fish harvest, while 62.5% was gradually returned to the environment by infiltration and transpiration throughout the production season. Increases in suspended solids and nitrogen and phosphorous levels were noted only in the last water of the season, and this did not usually exceed 0.3% of the entire volume of outflow water. It was confirmed that traditional carp farming plays a very positive role in water quality improvement. On average, 1 ha of carp ponds retained 167 kg of suspended solids, 2.6 kg of nitrogen, and 4.9 kg of phosphorous annually.
Keywords: carp ponds, water retention, nitrogen, phosphorous, suspended solids
Przyjęto po recenzji 09.05.2012 r.