Calendar and thermal time-based growth models for common carp and pikeperch, and the influence of stocking strategy in Lake Balaton, Hungary

Abstract

Common carp Cyprinus carpio and pikeperch Sander lucioperca are widely distributed and economically important freshwater fishes. Because these species are extensively stocked both within and outside of their native ranges, it is important to assess the effect of these actions. We aimed to analyse growth rate and its variability related to stocking strategy (season × lake area × habitat × fish size) in common carp and pikeperch in Lake Balaton (Hungary), based on cooperative tagging experiments with anglers. In both species, length increment was more closely associated with thermal time (degree-day sum) over 8 °C threshold water temperature than calendar time. Except a marked decrease with increasing fish size, stocking parameters had little effect on length increment. Growth models based on the GROTAG method and the von Bertalanffy's asymptotic length (L∞) and growth rate (K) are provided. Compared to other habitats, estimated growth rate proved to be high in common carp (128 mm year−1 at 300 mm standard length) and modest in pikeperch (61 mm year−1 at 250 mm standard length). We concluded that stocking rate even might be increased in common carp, while management of the pikeperch population should rather be based on catch restriction measures than intensified stockings.

Hyperstability in Electrofishing Catch Rates of Common Carp and Bigmouth Buffalo

“…In this study, boat electrofishing was only effective for Common Carp and Bigmouth Buffalo that had recruited to the age‐2 or age‐3 year‐class (Weber et al 2017), but due to fast growth of Common Carp and Bigmouth Buffalo, other gears biased for larger individuals may be adequate for estimating adult relative abundance. Common Carp catch rates fluctuate widely when different capture methods are used (Linfield 1980; Carl et al 2016; Specziár and Turcsányi 2018), but the efficacy of other sampling gears is unknown for Bigmouth Buffalo (Starrett and Barnickol 1955; Stang and Hubert 1984). The susceptibility of Common Carp and Bigmouth Buffalo to different sampling gears (e.g., gill nets, trammel nets, trawls, large seines, etc.)…”

“…Water temperature can have several different effects on electrofishing catchability because water conductivity and fish avoidance are positively correlated with water temperature (Reynolds et al 1996). In addition, water temperature can also affect fish location when fish move to avoid stressful temperatures; fish also move into littoral habitat during diel feeding and spring spawning periods (Bettross and Willis 1988; Reynolds et al 1996; Specziár and Turcsányi 2018). The effect of water temperature on electrofishing CPUE for Common Carp and Bigmouth Buffalo may bias estimates of relative abundance and should be accounted for when standardizing sampling through time.…”

Factors determining selective predation of the common carp on quagga versus zebra mussels

“…During the annual fish stocking, 300–350 tons of 2‐ and 3‐year‐old common carp are introduced into Lake Balaton (Specziár & Turcsányi, 2018; data source from the contractor, Balaton Fish Management Non‐Profit Ltd). The fish mostly inhabit vegetated littoral areas, where they co‐exist with dreissenids, and are specialised molluscivores consuming large quantities of dreissenids, which dominate their diet (Specziár, 2010; Specziár et al., 1997; Specziár & Turcsányi, 2018). Thus, the fish can be an important factor shaping mussel assemblages, affecting the outcome of interspecific competition between mussels if any differences in predation rate on both species and/or size classes exist.…”

“…The common carp ( Cyprinus carpio (L., 1758)), a cyprinid fish species with well‐developed crushing pharyngeal teeth, is a major predator of dreissenids in Lake Balaton (Specziár, 2010; Specziár et al., 1997). During the annual fish stocking, 300–350 tons of 2‐ and 3‐year‐old common carp are introduced into Lake Balaton (Specziár & Turcsányi, 2018; data source from the contractor, Balaton Fish Management Non‐Profit Ltd). The fish mostly inhabit vegetated littoral areas, where they co‐exist with dreissenids, and are specialised molluscivores consuming large quantities of dreissenids, which dominate their diet (Specziár, 2010; Specziár et al., 1997; Specziár & Turcsányi, 2018).…”