Growth dynamics of juvenile European plaice (Pleuronectes platessa L.)

• Main Author: Baranowska, Elzbieta, 1987-
• Other Authors: Háskóli Íslands
• Format: Thesis
• Language: English
• Published: 2016
• Subjects: Líffræði; Helguvík; Álftanes
• Online Access: http://hdl.handle.net/1946/24866

The productive nursery areas for many flatfish species are situated on European sandy shores, where both the quality and quantity of the habitat can control the recruitment processes. Juveniles metamorphose and settle at Icelandic nursery areas in early summer to maximize their growth and hide from larger predators during a span of few months before migrating deeper in the autumn. The main objective of the research was to analyse the growth patterns of plaice (Pleuronectes platessa) juveniles at the nursery ground in question. Samples of juvenile plaice were obtained bi-weekly from spring to fall at a highly fertile nursery area (Helguvík in Álftanes) from 2005 to present. Newly settled individuals were first observed at the end of May into early June and settlement, with 3 – 4 settling sub-cohorts, lasted until mid-summer with peak densities in June or July. The nursery ground period in Helguvík was short in comparison to European nurseries in general, but proved similar to nurseries at higher latitudes. Densities of settling plaice varied annually, with extremely high peaks observed in comparison to both Icelandic and other nurseries. In view of that, influence of density-dependent processes on growth was evaluated on three different scales; by comparing length measurement data to experimentally established maximum growth models, by otolith microstructure analysis and by evaluation of recent growth by increment width measurements. Maximum growth was visible in several years, at least during the early settlement period. Variability in growth was noticed both on intra- and inter-annual basis, and the influence of density dependent processes on growth was observed by analysis of increment width between two years with highly different settlement densities. Uppeldissvæði margra flatfiskategunda er að finna í evrópskum sandfjörum. Fjörurnar eru mikilvægar fyrir afkomu seiða og bæði stærð og gæði svæða geta haft áhrif á nýliðun. Botntaka skarkolaseiða (Pleuronectes platessa) hefst snemmsumars á Íslandi þegar ...