Moulting Lagoon has been recognised as a significant natural wetland on a state, national and also at an international level.
The Ramsar Convention is an international treaty that deals with the conservation and wise-use of the world’s wetland areas. ‘Ramsar’ is the name of the city in Iran where the convention was signed in 1971. Australia was an early signatory to this convention, and both Moulting Lagoon and the neighbouring Apsley Marshes (on private land) are on the Ramsar list.
Moulting Lagoon is listed primarily for its importance as a breeding ground for waterfowl. It holds the largest concentration of black swans in Tasmania, with an average between 8,000 and 10,000 swans living in the lagoon. Up to 18,000 have been recorded in times of drought. As well as fauna, the lagoon is important for its rare wetland and coastal flora. One of the most conspicuous plants in the reserve is beaded glasswort, a low growing succulent which covers large areas of foreshore. At any time of year the tips of the plant can turn deep red, adding a splash of colour to the shores of the lagoon.
The Japan-Australia Migratory Bird Agreement (JAMBA) and the China-Australia Migratory Bird Agreement (CAMBA) are two agreements which protect the passage of migratory birds between our countries, and the maintenance of their habitats. The Moulting Lagoon Game Reserve hosts several birds listed on these agreements, including the largest known flocks of migratory common greenshank in Tasmania.
Moulting Lagoon/Great Oyster Bay is a site of geoconservation significance, and the spit at Nine Mile Beach is one of only two mid-bay spits in Tasmania.
Moulting Lagoon and Great Oyster Bay are composed of a down faulted (Graben) block which developed following the separation of Antarctica and Australia which started approximately 70 million years ago. Rivers flowing through this valley feature deposited Tertiary sediment derived from erosion of nearby mountains. The underlying rocks are predominantly Jurassic dolerite and Permian and Triassic sediments.
The Great Swanport estuary was created by the development of a mid-bay spit (Nine Mile Beach) as sea levels started rising some 10,000 years BP. The restriction of flow has resulted in the flooding of the surrounding low-lying land (Moulting Lagoon) and the formation of extensive mudflats where silt carried down by the rivers has been deposited.
Moulting Lagoon has significant cultural values.
At the time of European settlement Moulting Lagoon was part of the territory occupied by the Oyster Bay nation. Wildlife around Moulting Lagoon, black swan eggs in particular, was an important food source to Aboriginal people. The majority of bands in this nation used the lagoon on a seasonal basis, while the Linetemairrener people lived at the lagoon year round.
Since European settlement, recreational hunting has been a common use for the lagoon, owing to the large numbers of ducks and swans. Up to 150 duck hunters still use the lagoon, mostly from the local area. While it is important to protect native species, the Ramsar Convention acknowledges that wise-use of wetlands is also important, and the open season between March and June is well regulated to ensure that the harvest of birds is sustainable. On the road in to Coles Bay, you may have noticed structures on the surface of the lagoon – these are actually duck hunters’ hides.
For further information about the area, read the Moulting Lagoon Game Reserve Management Plan 2003
For information about the Ramsar Convention, visit http://www.ramsar.org/