Designing a standardised sampling method for invertebrate monitoring: a pilot experiment in a motorway retention pondThe implementation of the European Water Framework Directive revealed the necessity to develop new tools designed for freshwater ecosystems monitoring. As a new assessment approach employing invertebrate monitoring, three artiſcial substrates (two benthic and one pelagic) were tested for 7, 14, 21 and 35 days of exposure in a motorway retention pond located in Southern France. Two of these artiſcial substrates appeared to sample too narrow a range of taxa, which was conſrmed by two-way ANOVA tests and diversity and evenness indices. Samples taken by the remaining artiſcial substrate, composed of six plastic plant stems ſxed on a 15 × 15 cm square tile, were representative of the species assemblage found in the stormwater retention ponds. The use of an artiſcial substrate as a standardised method for long term invertebrate monitoring in ponds holds much potential.