Flora and Fauna

Vegetation in the three A-Class Reserves includes marshes, samphire flats, sedge-banks and areas of woodland and shrubland.

The federally Threatened Ecological Community of Saltmarsh is present at both Alfred Cove and Pelican Point, and with less than 1% remaining of the original extent on the Swan Estuary, it warrants our careful protection.

Vegetation

Although little of it remains, natural vegetation along the margins of the Swan River Estuary is both unique and diverse, varying significantly with soil-types and other physical considerations. Vegetation in the three A-Class Reserves includes marshes, samphire flats, sedge-banks and areas of woodland and shrubland.

Principal among the upper-storey species is Eucalyptus rudis; while Melaleuca rhaphiophylla and Melaleuca cuticularis with Casuarina obesa form a middle storey, and Juncus kraussii the main species of sedge.

Samphire forms a low shrub community that includes species such as Sarcocornia blackiana and Suaeda australis.

Each of the Reserves suffers extensively from weed infestations, such as Ferraria crispa (black flag) in Milyu; Schinus Terebinthifolius (Brazillian pepper tree), Typha orientalis (bulrush) and Pennisetum clandestinum (kikuyu grass) in Alfred Cove, and Leptospermum laevigatum (Victorian tea tree) in Pelican Point.

In the Marine Park, seagrass meadows help stabilise the river floor and provide an important food source and habitat for hundreds of marine animals, including a nursery habitat for fish and crustaceans, as well as a carbon sink. The seagrass (Halophilia ovalis) is a vital component in the ecology of the Estuary.

Ever-Changing Fauna

A huge variety of local and migratory birdlife is supported by the Swan Estuary Marine Park and the adjacent A-Class Reserves. Waders, shore birds and bush birds rely heavily on the habitat provided for feeding, breeding or resting.

Unfortunately, due mainly to habitat loss, a number of the species which were once abundant are now threatened. This increases the importance of maintaining the ecological health of remaining areas.

Many small mammals such as the southern brown bandicoot (Isoodon obesulus) and the brushtail possum (Trichosurus vulpecula) have disappeared - replaced by feral cats, foxes and rabbits. However, in recent times, evidence of the lovely little Rakali or Australian Water-rat (Hydromys chrysogaster) has been found. Because rakali rely on a good supply of invertebrates, their presence is considered to be an encouraging indicator of good riverine health.

River dolphins use the adjacent waters, and a variety of fish species - including the yellow-eye mullet (Aldrichella forsteri) and cobbler (Cnidoglanis macrocephalis) - and prawns use the shallows and sea-grasses as both a juvenile nursery and feeding ground.

Other aquatic fauna include molluscs, polychaetes and crustaceans.

Please refer to the guides and bird lists complied by Birds Australia Western Australia for further information.

Birdlife of the Swan Estuary Reserves

These wonderful photographs provided by Tim Graham-Taylor and John Vogel show some of the birdlife to be found in the Swan Estuary Marine Park and adjacent nature reserves.

While by no means a comprehensive record of all species using the Estuary, the photographs illustrate the rich diversity of local, nomadic and migratory birdlife we are fortunate to encounter - and which we strive to protect.

 

Tim Graham-Taylor


 John Vogel