The Valle Smarlacca lagoon is located on the North western Adriatic coast of Italy, in the Emilia-Romagna region. The lagoon is part of the Valli di Comacchio lagoon system(44.58°N, 12.23°E), a wide complex of shallow water impoundments (see the Valli di Comacchio information sheet). Valle Smarlacca is located in the southeast corner of the Valli di Comacchio, close to the Reno River. It has a surface area ofabout 2 km and a mean water depth of 0.8 m. The surficial sediment is mainly composed of organically enriched silts. This organic layer is 10-20 cm thick and overlies a deeper clay layer. The aquatic phanerogam Ruppia cirrhosa forms patchy meadow, alternating between areas of dense canopy and areas devoid of plants [..]