Variability of pikeperch Sander lucioperca (L. 1758) cohorts in early life history

Abstract

Year to year fluctuations in 0+ fish cohort strength are a common phenomenon. Many factors can affect cohort strength during the fish's early life period. In this study, development of a 0þ pikeperch Sander lucioperca cohort in the pelagic zone was studied by trawling for 50 days from first larvae hatching, in two consecutive years. In 2007, an abundant S. lucioperca cohort collapsed suddenly soon after hatching. After the incident, slow-growing S. lucioperca prevailed in the catch. In 2008, the catch gradually increased during the whole study period because of prolonged hatching. Environmental factors differed mainly in a slower temperature increase, higher water level and higher zooplankton abundance in 2008 compared to 2007. Our study revealed that a strong 0þ S. lucioperca cohort at the time of hatching might not result in a strong S. lucioperca cohort in general.

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

“…In addition, an unknown number of pikeperch could have been flushed into the reservoir from ponds in the catchment area during high discharges (Pavlov et al, 2008). Despite the presence of a viable pikeperch population, natural recruitment is highly variable between years (Blabolil et al, 2016(Blabolil et al, , 2019.…”

Long‐term monitoring of pikeperch (Sander lucioperca) populations under increasing temperatures and predator abundances in the Finnish coastal waters of the Baltic Sea

“…Regarding other ecosystem effects, the increasing temperatures in the Bothnian Bay benefit many cyprinid fish species more than the perch (Lehtonen, 1996), which can shift predation pressure caused by the pikeperch from the perch to the cyprinids. and temperature, other conditions, such as those related to food availability, can also be important, with a strong cohort at the time of the hatching not necessarily resulting in a strong cohort of survivors until the end of the year (Blabolil et al, 2019). Nevertheless, consecutive warm summers can be important also in lowering population fluctuations and in keeping the population biomass, competition, and cannibalism at high levels for extended periods, which may further cascade into changes at the ecosystem level (Doney et al, 2012).…”

High Mobility and Flexibility in the Habitat Use of Early Juvenile Pikeperch (Sander lucioperca) Based on a Mark-Recapture Experiment

“…The main purpose is drinking water storage; therefore, a long-term biomanipulative management strategy is implemented, aiming for a high abundance of piscivorous fish controlling planktivorous fish, and a high abundance of large Cladocera improving the water quality through filtration of phytoplankton. A viable pikeperch population has been established in the reservoir, but fluctuating natural recruitment has been observed from year to year [13,14]. Therefore, pikeperch have been stocked since 1979 at a rate of 2500 to 25,000 fingerlings per a year (early autumn fingerlings [26,29]).…”

“…Early juvenile pikeperch were recorded to have undertaken diurnal migration from near the surface habitats at nighttime to deep benthic Diversity 2023, 15, 720 2 of 11 habitats at daytime in shallow, well-mixed reservoirs [11] or to inhospitable bathypelagic layers with cold water and low oxygen concentrations in the deep, stratified reservoirs at daytime [6,12]. Because annual fluctuations in year class strength are common in pikeperch populations [13,14], understanding the ecology of early life stages, including dispersal ability, is the first step in uncovering the factors affecting variable population recruitment.…”