Changes to estuarine habitat and migratory shorebird populations in the Hunter River, NSW, Australia
Most migratory shorebird species rely on coastal habitats in their non-breeding range, often competing with human populations. The Hunter River estuary, New South Wales (NSW), Australia, is the most important migratory shorebird site in NSW but it has been modified significantly since European settlement began in 1801. The city of Newcastle now forms a highly industrialised and urbanised complex in the lower catchment, and is one of Australia’s most important coal ports. Part of the estuary was listed as the Kooragang Nature Reserve in 1983, as a wetland of international significance in 1984 (Ramsar) and as a site in the East Asian-Australasian shorebird network in 1996. Significant dredging and draining of the Hunter estuary have destroyed or degraded shorebird roosting and feeding habitat. We compared trends in shorebird numbers to two other non-breeding sites in southeast Australia: the Shoalhaven River estuary (NSW); and the Corner and Shallow Inlets (Victoria) from 1982 - 2006. Significant declines in total numbers of migratory shorebirds were observed at the three sites. We also examined trends in migratory shorebird numbers in the Hunter estuary from 1965 - 2006. Severe declines were recorded for Curlew Sandpiper (Calidris ferruginea) and Lesser Sand Plover (Charadrius mongolus) populations (1982 – 2006). Changes to estuarine habitat at these non-breeding sites have probably contributed to declines in shorebird populations along the East Asian-Australasian flyway. The management of shorebird populations depends on the protection of habitats along the entire flyway. Changes to shorebird populations have occurred in the Hunter estuary, despite the site being protected in the reserve system. There needs to be a greater emphasis on effective protection of remaining shorebird habitat at this site, given the potential for further loss of shorebird habitat to port development and the negative impacts of a major dam planned for the upper catchment.