By Charlotte Simpson-Young and Asa Wahlquist
The Glebe Foreshore Walk has the only ‘mangrove forest’ in the City of Sydney. The little groups of mangroves can be found along the foreshore near at Federal Park and the border of Jubilee Park and Blackwattle Bay Park. The Bicentennial Park Stage 1 masterplan of 1987 originally proposed a much larger area in Jubilee Park. The final area is about one-third of that originally proposed because the Save Rozelle Bay community group objected to the scale, arguing it would result in a major loss of open space.
The term ‘mangroves’ is a bit confusing. “Mangrove” means species trees, shrubs, palms or ferns that are greater than 0.5m tall and grow in the intertidal zone and estuarine environments. But it can also mean a community of plants made up of these species. An impressive 18% of Australia’s coastline is made up of mangrove communities.
Mangrove species have evolved to deal with stressful environments. They need to cope with changes in water level, shifting sediments, low oxygen in the soil and high salt levels. Mangrove species have adapted to these conditions. For example, to cope with salt they may have salt glands in leaves pump the salt out onto the leaves. The grey mangrove (Avicennia corniculatum) planted at Jubilee park, it gets its name from the silvery-grey undersides of the leaves, which bear salt glands.
Some mangrove species have pneumatophores, upright breathing roots, which take in oxygen at low tide and allow the roots and shoots to survive inundation at high tide. They also help stabilize the plant in the sediment as it moves with the tide and helps trap sediment stopping it from washing away. They are essential to the survival of the plants but are vulnerable to damage by people and dogs walking across the area.
The first mangrove planting at Jubilee Park in 2006 had a rocky start. They are very difficult to propagate. But Professor Bill Alloway, from the University of Sydney, had some success with transplanting seedlings. After the first year, only 20 of the 200 seedlings planted had survived. Since then they have survived several episodes of damage, and there have been supplementary plantings. There were massive germinations of seedlings in 2015 and 2016, spreading the plants across the whole area.
For the original articles go to Asa Wahlquist’s website and for more posts on the Glebe Foreshore:
Benson, D., Howell, J., (1995) Taken for Granted: The Bushland of Sydney and its Suburbs. Kangaroo Press.
Buckingham, J., (2008) Glebe’s waterfront History, the last 40 years <https://www.abc.net.au/radionational/programs/offtrack/flowerpots-tackle-sydney-harbours-aquatic-housing-crisis/6148966>
Christie, Judy (2019) personal communication
City of Sydney (2006) East Glebe Foreshore Plan of Management <https://www.cityofsydney.nsw.gov.au/__data/assets/pdf_file/0003/138756/GlebeForeshoreEastPoM_adopted.pdf>
City of Sydney (2016) Glebe Foreshore <https://www.cityofsydney.nsw.gov.au/vision/better-infrastructure/parks-and-playgrounds/completed-projects/glebe-foreshore>
City of Sydney (2014) Urban Ecology Strategic Action Plan <https://www.cityofsydney.nsw.gov.au/__data/assets/pdf_file/0011/198821/2014-109885-Plan-Urban-Ecology-Strategic-Action-Plan_FINAL-_adopted.pdf>
City of Sydney (2019) Johnstons Creek <https://www.cityofsydney.nsw.gov.au/explore/facilities/parks/plans-of-management/johnston-creek-parklands>
City of Sydney (2013) Johnstons Creek Master Plan Report <https://www.cityofsydney.nsw.gov.au/__data/assets/pdf_file/0003/154803/Johnstons-Creek-Parklands-Master-Plan-August-2013_Part-1_Vision-and-Analysis.pdf>
City of Sydney (2016) Avifauna Surveys: City of Sydney <https://www.cityofsydney.nsw.gov.au/__data/assets/pdf_file/0003/306651/Avifauna-survey-spring-2016autumn-2017.pdf>
City of Sydney (2019) The City of Sydney Significant Trees Register <https://trees.cityofsydney.nsw.gov.au>
Department of Primary Industries (2019) Fishing in Sydney Harbour <https://www.dpi.nsw.gov.au/fishing/recreational/fishing-skills/fishing-in-sydney-harbour>
Eckstein, D., (2001) Inner City Environmental Revitalisation <https://ramin.com.au/annandale/wetlands.shtml>
Irish, P., Goward, P. (2013) Blackwattle Creek, Barani: Sydney’s Aboriginal History <https://www.sydneybarani.com.au/sites/blackwattle-creek/>
Larkum, T., (2007) The Mangrove plantings on Rozelle Bay, Glebe Society Bulletin <https://www.glebesociety.org.au/wp-content/uploads/bulletins/2007_03.pdf>
Larkum, T., (2017) Damage to Mangroves in the Mangrove Area of Bicentennial Park, Glebe Society Bulletin <https://www.glebesociety.org.au/wp-content/uploads/bulletins/2017_07.pdf>
Marsden S., Solling, M., (2016) Harold Park: A History. Mirvac Group Limited. Sydney
Montoya, D., (2015) Pollution in Sydney Harbour, NSW Parliamentary Research Service <https://www.parliament.nsw.gov.au/researchpapers/Documents/pollution-in-sydney-harbour-sewage-toxic-chemica/Pollution%20in%20Sydney%20Harbour.pdf>
Schwartzkoff, L., (2018) Oyster Research Aims to Clean the Water of Sydney Harbour <https://sydney.edu.au/news-opinion/news/2018/09/27/oyster-research-aims-to-clean-the-water-of-sydney-harbour.html>
Solling, M. (2007) Grandeur and Grit, Halstead Press.