Saving saltmarsh at The Spit

9 October 2020

The Port Phillip and Western Port region is home to three Ramsar wetlands, listed as internationally significant under Convention on Wetlands of International Importance.

The Spit Nature Conservation Reserve near Point Wilson, is part of one of these Ramsar wetlands, and is home to some of the most significant areas of saltmarsh vegetation in south-eastern Australia.

The reserve lies within the Port Phillip Bay (Western Shoreline) and Bellarine Peninsula Ramsar site and supports endangered
species, threatened ecological communities and thousands of waterbirds. It also provides an important food source for fish and sustains a variety of species during critical stages in their lifecycles.

Aerial image of The Spit Nature Conservation Reserve
Aerial image of The Spit Nature Conservation Reserve

Through the Two Great Ramsar Wetlands project, the Port Phillip & Westernport CMA recently engaged Nature Glenelg Trust to investigate the potential hydrological causes of decline in the condition of the reserve’s saltmarsh vegetation.

Saltmarsh provide important habitat for many of Australia’s waterbird and shorebird species, including migrant waders such as curlews and stints. The saltmarsh community at The Spit Nature Conservation Reserve is a vital site for a small population of Orange-bellied Parrot (Neophema chrysogaster) that migrates across Bass Strait from Tasmania over the winter, non-breeding, season.

Pied Oystercatcher in saltmarsh vegetation at The Spit (Andrew Morrison)

The research found a series of impediments to the natural hydrology of the area feeding the saltmarsh vegetation community. These impediments include a road easement through the conservation reserve resulting in measurable restrictions of tidal movement entering and exiting the inland section of saltmarsh (60 hecatares). In addition, changes to the natural waterway within the immediate catchment has diverted freshwater flows away from the saltmarsh. The cumulative impact of these changes has resulted in a gradual decline in condition over many decades.

This work has provided a vital understanding of the complex hydrology ‘story’ of The Spit Nature Conservation Reserve. A series of recommendations have been identified to reconnect these important threatened ecological communities and will inform a restoration plan for the site.

This will be achieved through continued collaboration with stakeholders, partners and land managers, who are committed to the ongoing protection there internationally significant wetlands.

The Two Great Ramsar Wetlands is supported by the Port Phillip & Westernport CMA through the Australian Government’s National Landcare Program.