EN
In the paper there have been presented the results of a fi eld studies performed in 2001–2003 (carp breeding period), in order to establish the dynamism of the light conditions changes in a fi sh pond. The infl uence of shade caused by vegetation growing on the shore of the light conditions in the pond has been also analyzed. The results show a great changeability of the light conditions in a breeding period characterized by the tendency to worsen of the light conditions in the pond till the extreme conditions of a complete absorption of the sunlight by the surface layers of the pond water and, observed from the middle of June, 24 hours – night on the pond bottom.