Activity Patterns of Three Piscivorous Fish Species in a Reservoir Studied By the VEMCO Positioning System

Acoustic fixed telemetry monitoring allows to track aquatic animals over large areas during long periods. Pikeperch (Sander lucioperca), Pike (Esox lucius) and Perch (Perca fluviatilis), 3 piscivorous species, are often together in the European reservoirs. Our objective was to study the activity patterns of these species and temporal variability of the activity according to environmental parameters in order to better understand how they live together.

The 3 piscivorous species have been monitored in a French reservoir (80 ha) with the VEMCO Positioning System (VPS – 40 hydrophones) during two years (2012-2013). First the evaluation of the performances of the VPS system was assessed to get the main characteristics of our tracking system. Then, the activity of 60 individuals has been described with two metrics, minimum moved distance (daily and hourly) and home range (daily and seasonal).

During the day, the diel activity patterns of the 3 species were clearly different but a high variability was observed between individuals. Moreover, activity patterns were different between seasons but all species were active in winter. Finally, the metrics used to describe the activity were correlated positively with water temperature for perch and pikeperch, but not for pike.