A Visit to Western Port - Victoria’s Other Bay

Western Port on Victoria’s central coast is one the state’s largest embayments and is often the forgotten cousin of the larger and more highly populated Port Phillip. Western Port is part of the traditional home of the Boonerwurong peoples whose ancestors lived, fished, and collected food from the wealth of resources provided from the rich mudflats, mangroves, and deep channels that characterise this bay.

First charted by George Bass on his epic voyage of discovery in January 1798 after he sailed from Sydney in a 2.4m boat, called Tom Thumb, he named the bay Western Port because it was “west” of Port Jackson (Sydney). The discovery of Port Phillip did not take place for another few years.  Early reports of Western Port speak of a place of great natural abundance with boatloads of mud oysters being collected by early explorers and game in the form of bird life abundant.

Western Port covers an area of 680 sq kms of which 270 sq kms are exposed as mud flats at low tide. It contains two large inhabited islands, Phillip and French Islands, which are popular tourist destinations. Western Port’s marine and coastal habitats are extremely diverse and reflect the sheltered nature of the relatively protected waters. Extensive mudflats within the bay are in many areas covered with seagrasses, punctuated by the occasional rocky outcrop, while the coastal fringes are dominated by nationally significant saltmarshes and some of the largest mangroves in southern Australia.

Western Port’s surrounding catchments have been extensively modified with one of Victoria’s largest wetlands, the Koo Wee Rup swamp, to the north, having been drained and cleared for agriculture in the early 1900s. During the 1800's the Koo-Wee-Rup swamp covered an area of more than 40 000 hectares and was covered by dense stands of swamp paperbark, reeds and bulrushes. Continued change inland, on the western shoreline, associated with urban growth from Melbourne and the establishment of a deep water port at Hastings in the 1960s, and the clearing of the hills to the south east have all markedly altered the quality of water flowing into the bay. Current planning for population growth puts additional numbers, the size of Canberra, into the bays catchment. This development will clearly need to be managed carefully if further impacts on the bays already stressed systems are to be avoided

For the last few decades there has been enormous concern about the loss of seagrass within the bay. During the 1970s and 1980s a massive decline in seagrasses within Western Port resulted in loss of over 80% of this important bay habitat. Seagrass decline has been linked to poor water quality coming from the surrounding catchments. The quality of the water from its catchments continues to be a significant threat to the marine ecosystems of Western Port as do fine sediments eroded from a significant section of shoreline. An additional concern is that now that seagrass has disappeared there are large areas of fine sediment that are readily mobilsed by wind and water movements which add to the levels of turbidity and thus stress on the bays ecosystems.

In January and December of 2007, the sailing vessel Pelican 1, undertook a comprehensive research and community engagement program in Western Port as a part of the Two Bays project in partnership with a range of state agencies and local governments. The program aimed to focus attention on the health of the ecosystems within the bay and links with adjacent catchments, with a particular focus on water quality.

The overall aim of the Two Bays was to provide a platform for a range of research investigation on bay systems and processes, and to create a “space for ocean dialogue” between agencies, local government, industry and communities with key interests on the future of the bays.

The research program included programs exploring facets of water quality and bay habitats. Utilising some state of the art technology EPA Victoria led a comprehensive water quality monitoring program in which nutrient samples were taken very 20 – 40 seconds while the vessel was underway. GPS referenced, and coupled with a suite of physical and chemical sensors, providing a continuous picture of water quality within the bays. As part of a broader investigation into the impacts of climate change on bay processes a detailed examination of the exchange segments of the bay where Bass Strait water and bay water mix using advanced Doppler profiling techniques. The platform further provided for other studies including an investigation of historic contamination of sediments in a segment of the bay, and a ‘citizen science’ investigation of habitat values within one of the bay’s Marine National Parks.

Flow Injection Analysis system coupled to underway sampling system provided a detailed picture of water quality along the cruise track.

Doppler profiler & WQ loggers ready for deployment at a key choke point in Western Port

The space for dialogue was filled by a number of events all focussed on building understanding of the links between catchments and bay health. A forum hosted by the Port Phillip and Western Port Catchment Management Authority brought together senior industry, agency, community and local government representatives to explore opportunities for a major scientific study of the bays processes to fill a considerable knowledge gap and allow for better management in a time of climate change and rapidly increasing catchment population growth. A full day cruise around the northern section of the bay provided an important opportunity for agency and local government officers and representatives of key community interest groups to gain a first hand understanding of the values, threats and opportunities for partnerships in addressing challenges facing the bay. To provide the broader community with a chance come on board and meet with crew, scientists, and agency officers, open boat sessions were provided in berthing ports.

Reports and images from the two previous voyages can be accessed from the website www.svpelican.com.au. Pelican wish to acknowledge the support provided for Two Bays by EPA Victoria and Parks Victoria, in partnership with the Port Philip and Western Port CMA, Association of Bayside Municipalities, Victorian Coastal Council, Melbourne Water, People and Parks Foundation, Coast Action / Coastcare, and the Marine Discovery Centre, Queenscliff.

Pelican hopes to return to Western Port again in the summer of 2008.