Vasse-Wonnerup System Ramsar Site is a shallow, extensive, nutrient-rich wetland system with widely varying salinities. Water within the Site fluctuates from fresh to brackish depending on the season. It provides dry-season habitat for tens of thousands of resident and migrant waterbirds of a wide variety of species including the Australian shelduck (Tadorna tadornoides), Australian shoveler (Anas rhynchotis), black-winged stilt (Himantopus himantopus), and red-necked avocet (Recurvirostra novaehollandiae). It also regularly supports the largest breeding colony of black swan (Cygnus atratus) in south-western Australia. In winter, broad expanses of open water are fringed by samphire and rushes. There are melaleuca woodlands behind the samphire belt and eucalyptus woodlands on higher ground. The Vasse and Wonnerup lagoons (former estuaries) are the two principal components of the Vasse-Wonnerup System and act as compensating basins for water discharging from four rivers through the use of weirs (flood gates). The Site plays a vital role in flood protection for the town of Busselton. The surrounding area is used primarily for cattle grazing and potato cropping. The Site’s close proximity to residential, farming and tourism areas presents a range of management issues and opportunities.