EFFECTS OF STOCKING EARTHEN PONDS WITH PIKEPERCH (SANDER LUCIOPERCA (L.)) FINGERLINGS REARED IN RECIRCULATING AQUACULTURE SYSTEMS EFFECTS OF FISH SIZE AND THE PRESENCE OF PREDATORS

M. Hopko, K. Partyka, I. Piotrowska, A. Kapusta, B. Szczepkowska, Z. Zakęś, K. Wunderlich, M. Kozłowski, S. Jarmołowicz, A. Kowalska, M. Szczepkowski

Abstract: The aim of the study was to determine the effectiveness of stocking earthen ponds with pikeperch fingerlings reared in recirculating aquaculture systems (RAS). Three “natural” ponds with predators (pike – Pd ponds) and three ponds in which the pikeperch were reared in a monoculture (M ponds) were used. All of the ponds were also stocked with ide, tench and crucian carp (food base for the predatory fish). Each of the ponds was stocked with three pikeperch size groups: fish with body weights (b.w.) of 3.3 g, aged 102 days post hatch (DPH) (group S); b.w. 6.4 g, aged 128 DPH (group M); b.w. 25.4 g, aged 143 DPH (group L). Prior to stocking, each pikeperch size group was tagged with a different colored Visible Implant Elastomer (VIE). The fish were harvested from the ponds in early October. Neither pond type (M or Pd) nor the size/age of the pikeperch was noted to have impacted the final fish b.w. or condition, but both the pond type and the size of the fish impacted increases in stock biomass (MANOVA, P < 0.05). Significant differences were noted with regard to survival (Pd ponds – mean 29.7%; M ponds – 81.6%) and fish body deformations of the gill cover and jaw (group S – 14.1%, group M – 14.0%, group L – 31.2%). The results indicate it is more advantageous to stock with material that is smaller in size (b.w. 2–4 g). Tagging juvenile pikeperch with VIE was noted to be highly effective (retention 99.7–100%).

Keywords: fish size; pikeperch; pond stocking; RAS; Sander lucioperca

Date published: 2017-09-28