Integrated constructed wetlands: hotspots for freshwater coleopteran diversity in the landscape of Ireland

Abstract

Constructed ponds are small water bodies that have an enormous biodiversity potential. The creation of this habitat can be seen as a valuable ecological enhancement tool, as ponds can host a great number of species. Integrated constructed wetlands (ICWs) are a type of surface-flow constructed wetland formed by interconnected ponds that integrate their water treatment capabilities with other functions such as biodiversity enhancement, carbon sequestration and landscape fit, by virtue of mimicking natural wetlands. ICWs have been shown to have the potential to enhance freshwater macroinvertebrate diversity in Ireland, especially Coleoptera diversity, in agricultural areas due to their unique design adaptability. A total of 67 water beetle taxa were found to inhabit the 15 studied ponds in the Annestown River catchment, Co. Waterford. Furthermore, when the taxa that have the potential to inhabit ICW ponds in Ireland were included a total of 82 water beetle taxa was obtained, which represents 26% of the known Irish aquatic lentic coleopteran fauna and includes several species of conservation interest. If the potential of these small water bodies to support water beetle diversity and that of other aquatic macroinvertebrates is to be maximised, particular attention should be paid to enhancing the range of mesohabitats within the ICW system.