The influence of littoral type at presence and absence of young of the year (YOY) pike (Esox lucius L.) on growth and diurnal behaviour of YOY pikeperch Stizostedion lucioperca (L.) was investigated in triplicate (7.5 m2) field enclosures. Three types of littoral zone were applied: with homogeneous macrophytes (HOM), with heterogeneous macrophytes (HEM) and with woody debris (WD), together with control enclosure–without any structure (C). The type of littoral zone influenced the growth rate and behaviour of YOY pikeperch. The growth rates of small (<60mm) pikeperch were significantly higher in HOM than in controls, HEM and WD types of littoral. Similar but weaker relationships were found for larger pikeperch (>60mm) with their growth rates higher in HOM than in HEM and WD littoral types. At the presence of pike, the highest pikeperch growth rate was still noted in HOM, compared to WD enclosures. The results of pikeperch diurnal behaviour showed high littoral use at absence of pike (on average: 38% for C, 62% for HOM, 55% for WD, and 30% for HEM enclosures). Pikeperch utilised littoral habitat much less at presence of pike (15% for C, 8% for HOM, 3% for WD, 6% for HEM enclosures). On the basis of experiments it can be concluded that pikeperch growth rate and behaviour may be strongly affected by diversified littoral zones and by the presence of pike competition. Observed relationships may be applied for water quality control in reservoir. As a strong pikeperch population, achieved by enhancement of its growth through creation of most preferred nursery habitat (HEM), may enable to reduce zooplanktivorous fish community even in the presence of pike competition.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.