A complex of freshwater wetlands on the eastern Padana plain. Habitats include open water, reedbed, riverine woodland, wet grassland and agricultural areas crossed by three rivers. The area can be divided into the following subsites: Valle Santa, a wetland with reedbeds, Typha beds and wet grassland; Val Campotto, a wetland half-covered by water-lilies Nymphaea; Bassarone, an open water-body. The surroundings are mainly cultivated with maize, wheat, and poplar Populus plantations. The main use of the site is for nature conservation and researchit is the main bird-ringing station in Italy.
There is a large heronry of Nycticorax nycticorax, Egretta garzetta and Ardeola ralloides, as well as the largest Italian colony of Phalacrocorax carbo. Winter waterbird data refer to January 1994 counts only. Species of global conservation concern that do not meet IBA criteria: Aythya nyroca (2-3 pairs breed), Acrocephalus paludicola (rare on passage).
Pressure/threats to key biodiversity
There are two main threats. Coypu Myocastor coypus (an introduced, non-native aquatic rodent) have caused breeding Chlidonias hybridus to decline by largely destroying the cover of water-lilies Nymphaea. Nitrates and phosphates from agricultural fields are polluting the wetlands with excess nutrients. Some or all of the site is covered by a management plan. Coypu numbers are controlled by the local management body (Consorzio di Bonifica Renana). There is regular monitoring of herons and Phalacrocorax carbo by the Università di Bologna. Species listed in the EC Habitats and Birds Directives are censused by Regione Emilia Romagna.
National High International HighIBA contains Wildlife Reserve (Valli Argenta e Marmorta, area not known). 2,000 ha of IBA covered by Regional Nature Park (Delta del Po, 59,118 ha). 1,830 ha of IBA covered by Special Protection Area (Valle Santa e Val Campotto, 1,830 ha). 1,363 ha of IBA covered by Ramsar Site (Valle Campotto e Bassarone, 1,363 ha). 261 ha of IBA covered by Ramsar Site (Valle Santa, 261 ha).