The level of predation used as an indicator of tagging/handling effects

In most telemetry studies, there can be adverse effects of capture, handling and tagging. Possible tagging effects include impaired competitive performance and predator avoidance. These effects are not easily studied in the laboratory, and field studies include too much variability to test such indirect effects. Predation experiments were conducted in four outdoor ponds to test for the possible effects of transport/handling and tagging by surgical implanting. Pikeperch, Sander lucioperca (L.), were used as predators and trout, Salmo trutta (L.), as prey. The level of predation was highly dependant on water temperature, but no significant difference was seen in the level of predation between any of the treatment and control groups. This can be interpreted as a lack of effect or as a failure to detect such effect under less than field conditions.