Is meiofauna community structure in Artificial Substrate Units a good tool to assess anthropogenic impact in estuaries?

The applicability of estuarine meiofauna and harpacticoid copepods' communities in an artificial substrate unit (ASU) was assessed and compared to natural substrates (sediment and pneumatophores) as a tool to discern estuaries under different types of anthropogenic impacts. The ASU's replicates demonstrated a low variation of density among replicates when considering the total meiofauna and copepod species, which was reflected by a great similarity within the samples. In relation to the most abundant groups found, the ASU samples properly represented the natural substrates, even though nematodes were poor colonizers. That the ASU only showed significant differences between areas suggested that standard substrates could more efficiently detect the differences between communities and pointed toward the applicability of ASUs meiobenthic communities as useful tools for impact studies. •Artificial Substrate Units (ASUs) distinguished estuaries under different impacts.•ASUs were good tools for assessing impact in meiofauna communities.•For the first time natural and ASU communities were statistically compared.•ASUs were good representations of natural substrates for meiofauna.