Occurrence of the freshwater invasive snail Potamopyrgus antipodarum in Madeira Island (Portugal): distribution and impacts on benthic communities

Map of Madeira Island with 13 sampling sites from 6 streams: 1- Ribeira da Janela (downstream), 2- Ribeira da Janela (middle stream), 3 – Ribeira da Janela (upstream), 4 – Ribeira de São Vicente (downstream), 5 – Ribeira de São Vicente (upstream); 6 – Ribeira do Faial (downstream), 7 – Ribeira do Faial (upstream), 8 – Ribeira dos Socorridos (downstream), 9 – Ribeira dos Socorridos (upstream), 10 – Ribeira Brava (downstream), 11 – Ribeira Brava (upstream), 12 – Ribeira da Tábua (downstream), 13 – Ribeira da Tábua (upstream).