The saltwater paperbark (Melaleuca cuticularis) is a common feature along the fringes of south coast estuaries. Here the interplay of light and water produces pleasing reflections in the Wellstead Estuary at Bremer Bay.
The foreshores of estuaries are ever changing as water levels control the dynamic processes of erosion, sedimentation and colonisation by vegetation. Bank erosion, (Stokes Inlet, September 2009) in one location, due to high water levels and strong wave action, has built a nearby sand spit. Young Saltwater Paperbark trees (Melaleuca cuticularis) have successfully colonised the new ‘dune’ edge while old dead paperbark trees can be seen in the developing ‘inter-dune wetland’.
A layer of marine sediments called Spongelite covers large areas of the South Coast of Western Australia. Spectacular formations can be found where rivers cut through the multicoloured layers. Here a brick red outcrop of spongelite contrasts strongly with the quartz pebble scree slope.
This caddisfly larvae (Trichoptera: Hydroptilidae) appears to be restricted to a small stream west of Albany and was first collected in 2006. The cylindrical silk secretion case is unusual for southern Australian hydroptilids but common in the tropical north. Hydroptilids feed on microscopic algae. The grid cells in the background are 1mm square.
The rivers of the eastern south coast of Western Australia do not flow all year round and the river pools often require a large rainfall event in the upper catchment to refill them. The left photo was taken in May 2006 and the right hand photo on 25 June 2011. Water salinity can increase dramatically through evapo-concentration. The aquatic fauna of the region is well adapted to these variable salinity conditions.