Epsilon Archive for Student Projects

Abstract

Ecological traps occur when organisms select habitats that appear suitable but are ultimately detrimental to their health and survival. Wastewater treatment plants (WWTPs) could contribute to the occurrence of ecological traps by emitting harmful pollutants into aquatic ecosystems where organisms live, potentially altering the behaviour and habitat preferences of aquatic species. This study examined the behavioural responses of boatman bugs (Corixidae) and damselfly larvae (Zygoptera) to treated WWTP effluent in a two-choice cue experiment. The experiment was conducted in a laboratory setting over two trials where the insects were exposed to cues from treated wastewater and clean tap water. Their behaviour was analysed using video tracking software to assess habitat choice, proximity to wastewater outlets, and activity levels. In trial 1, boatman bugs showed a significant avoidance towards the wastewater and the damselfly larvae showed a weak avoidance. Here, the median of the damselfly larvae was only slightly below 0.5 in the first trial, which could also potentially be read as indifference. In trial 2, both insects exhibited a significant preference for the wastewater. The fact that both species spent more time in the wastewater zone in trial 2 suggests possible habituation or attraction. These findings support the idea of WWTPs playing a role in the occurrence of ecological traps, highlighting the need for improved wastewater treatment and further research on the effects of contaminants on aquatic insects. Understanding these dynamics is crucial for creating sustainable management practices to conserve aquatic ecosystems.