Franciszek Pistelok, Maciej Pilarczyk, Ludmiła Kolek, Aleksandra Jankowska
ABSTRACT. In 2012-2014, field studies were conducted with the aim of verifying the impacts different techniques of fertilizing ponds had on environmental conditions and the production of carp fry. The results obtained from the experiment confirm that mass fish kills occurred in the early spring, which led to the low production of fry. Based on the analyses of mean values of individual weight and stock survival in the various treatments tested, it can be concluded that the decided majority of losses were incurred at the beginning of the production season. However, because of low stock survival in 2013 and 2014, the accelerated mineral fertilization and supplementary feeding applied that was aimed at stimulating the development of natural food did not have the desired effect of increasing carp survival. Thus, it must be concluded that stock losses can be the result of a combination of many factors: new types of pollution or overall physicochemical water conditions that could have been an indirect cause of starvation stress that resulted in weakened fish condition and higher susceptibility to disease.
Keywords: trophic conditions of ponds, fertilizing ponds, carp fry survival
Przyjęto po recenzji 25.11.2015 r.