Constructed wetlands (CWs), originally designed to mitigate chemical water pollution, often host noticeable aquatic fauna. However, little is known about the impact of the contaminants circulating within CWs on this local fauna, questioning the role of CWs as ecological refuges or traps. We aimed to assess the potential of an agricultural CWs in northern France to act as an ecological trap for aquatic fauna and the potential consequences on wetland functioning. We made faunistic inventories of benthic macroinvertebrates, using litterbags, from March to June 2022 in two zones within the CWs with contrasting levels of agrochemical contamination and in one unpolluted comparison pond. We calculated community diversity and sensitivity indices (e.g., species at risk, SPEAR