We live in the glorious eastern suburbs of Sydney overlooking Parsley Bay, on the outer end of Sydney Harbour. This funnel-shaped re-entrant offers one of those delightful out-of-the way spots enjoyed by those privileged to live nearby and weekend visitors. The name Parsley comes from either a native plant discovered by early convicts or the name of a hermit who lived in one of its caves. Since 1909 it has formed a public reserve under the care of the local council through the efforts of its dedicated staff and local residents.
A steep wooded gully provides the backdrop to the waters of the bay. In itself this gully offers richness in flora and fauna traversed by a creek that cascades over rock ledges. The gully was carved into Hawkesbury Sandstone during the Cainozoic to levels below present sea level. Overhangs and shallow caves line the gully flanks. On the margins of the bay the sea has cut a narrow shore platform revealing the crossbedding of the ancient river that laid down sand layers way back in the Triassic. Iron staining within the sandstone offers an array of case-hardened micro features with hollowed notches containing loose sand reminding one of the fragilities of gully overhangs. As in many parts of the Sydney coast where shore platforms abound, there is the perpetual mystery of age and process in their formation. Were higher sea levels involved, to what extent did water-layer weathering play its part, and were wave energy levels that much greater in mid Holocene and perhaps Last Interglacial times? These imponderables fascinate me every time I place my towel on one of the benches! And the dreaming continues as one also ponders where sea level is heading around the rocky shores of this bay.
The inner part of the bay is enclosed by a so-called shark net. I say so-called as bull sharks and huge rays have been found inside the net; from time to time, I report holes. But you still feel safe and the net is a haven of marine life. The bed of the bay is marine sand presumably a part of the expanded flood-tide delta of Sydney Harbour. During periods when swell waves from far offshore swing into the Harbour the bed is swept into sand ripples. But over time burrowing organisms and stingrays obliterate the ripples.
Parsley Bay is rich in life including the semi-aquatic eastern water dragon. Rocky platforms abound with molluscs and I am often amazed at the speed with which periwinkles and limpets colonise wetted pathways on a rising tide. Seagrasses and brown kelp occur in abundance offering places for fish to hide. Irene and I have become keen snorkelers always trying to find different species of fish. It is so changeable. On occasions bream may dominate along with luderick; then schools of bait fish may flash past; somewhere else we may find the small stripped fish known as mado, or cuttlefish or flute mouths staying motionless. Visibility in summer when the water temperature hovers in the low 20 degrees C, is around 5m; in cooler waters of spring it can exceed 10m. However, no matter what the visibility we cannot find those enigmatic sea horses that colonise the net amidst the kelp. We are assured they are there, but others like us spend lots of time looking. To compensate we do find other wonderful creatures such as leatherjackets and colourful sponges.
The bay has a colourful history as part of the Wentworth Estate; it was the base of a Japanese Antarctic expedition (1910-12), and a wonderful playground for picnickers. My first visit was on a Sunday School picnic and it is still used by school groups. Playground facilities have recently been upgraded by Woollahra Council and parking is free! Fishing (and diving) off the jetty located outside the net is attractive to many visitors from all over Sydney; only this week we saw caught a very large flathead and once we witnessed a huge battle with a powerful kingfish which got away at the last minute. Straddling the bay is a remarkable suspension bridge now 110 years in age. It scares me to see young boys jumping from the bridge at high tide.
Over time, we have seen some significant changes to bay conditions. In the 1930s, the council dredged the bed of Parsley Bay to enlarge the picnic ground. This created a hole in which fine sediments and contaminants accumulated making it quite messy to walk in shallow waters. Action was needed and a group of local residents called “Friends of Parley Bay”, of which we became members, sprang into action. During the early years of the Howard Government when Robert Hill was Environment Minister, there were funds from the sale of Telstra under the Coasts and Clean Seas Program to undertake innovative works. Well surely it would be innovative to clean out/rehabilitate this polluted bay? Local Council and residents raised matching funds assisted by Ian Kiernan of Clean-up Australia fame (the NSW Government did not give funds only permission to proceed). The result was a smoothed sand bed now partly colonised by kelp. Of interest has been the progressive build up of sand against the seawall built in the 1930s separating the beach from the lawns of the picnic area. This federal-local investment is clearly paying dividends in improving the ecological and social well-being of the bay.
Further change is on its way. During World War 1, the Vaucluse-Watsons Bay sewer system was fed into a pit in the flat area at the rear of the bay. Few residents know about this history. It involved construction of a tunnel under the bedrock peninsula for sewer and storm waters to emerge at the base of the ocean cliffs at Christison Park. Here we have a totally non-treated sewer outfall that continues to this day. At times there are overflows into Parsley Bay. This is about to change. Parsley Bay will still receive the local sewage and the 100 year old tunnel will then serve as a storm overflow, but the main flow will be diverted via a pipe underground to Rose Bay where it will connect to the system that discharges in deeper water through the Bondi sewer works. So for a period we expect access to Parsley will be limited—we hope this will be a wintertime activity. I am assured the works will not interfere with marine life and use of the bay waters.
So now it is time to think of our swim tomorrow at Parsley Bay.
Words by Prof Bruce Thom. Please respect the author's thoughts and reference appropriately: (c) ACS, 2019, for correspondence about this blog post please email firstname.lastname@example.org