Influence of habitat on abundance, size and growth rate of pikeperch (Sander lucioperca) 0+ juveniles in a canyon‐shaped reservoir

Abstract

AbstractAbundance, size (standard length, LS) and growth rate of early pikeperch (Sander lucioperca) 0+ juveniles were monitored in the epipelagic and bathypelagic layers near the dam, and in the middle and upper sections at the canyon‐shaped Římov Reservoir (Czech Republic) during the day on 26 and 29 May, and during the night on 5 and 11 June in 2008. The greatest abundance of 0+ fish was observed in the middle section of the reservoir and their LS increased upstream from the dam towards the reservoir's tributary. Moreover, larger and older pikeperch 0+ juveniles migrated to the bathypelagic layer during the day. The epilimnetic temperature and productivity (expressed as chlorophyll‐a concentration) gradients were suggested as the main drivers affecting the distribution and growth of the fish.