Model of energy flow in the bottom sediments of littoral zone of a dam reservoir with regard to detritivorous roach, Rutilus rutilus (L.)

Data obtained from April to October 1995 (196 days) were used for work out the model of energy flow through the bottom sediments of littoral zone of Dobczyce Reservoir (southern Poland) with special regard to algae, bacteria and roach, Rutilus rutilus (L.) - dominating species in ichthyofauna of this reservoir. In the surface layer (0.5 cm) of bottom sediments ash free organic matter (2061-5534 kJ m^-2), biomass algae (88-357 kJ m^-2) and bacteria (0.26-6.69 kJ m^-2), primary (19.3-83.8 kJ m^-2 24 h^-1) and secondary production (0.4-185.9 kJ m^-2 24 h^-1), and respiration of epibenthic communities (124-297 kJ m^-2 24 h^-1) werw determined. The density of roach (mean values 5.6 g m^-2) and their daily food ration (4.6-60.8 J m^-2 24 h^-1) were also appointed. The data showed that the participation of roach in the pool of energy taken awey beyond the bottom was very small and equalled 0.01% of total pool of energy (40118 kJ m^-2 196 days^-1) released.