Badu Intertidal Wetlands are a highly altered mangrove and salt marsh ecosystem. The mangroves that once lined Parramatta River have been limited in extent, polluted and altered by industrial land uses and surrounded by rapidly growing urban populations. While much is being done to manage this ecosystem they are likely to remain highly vulnerable.
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1. Spatial Patterns and Dimensions
Location and altitude
Badu wetlands are located 12km West of the Sydney CBD.
Being intertidal in nature, Badu is entirely within the tidal range of 0m-2m. However, Casurina swamp forest is an adjoining ecosystem which reaches 5-10m above sea level.
Badu wetlands are located 12km West of the Sydney CBD.
Being intertidal in nature, Badu is entirely within the tidal range of 0m-2m. However, Casurina swamp forest is an adjoining ecosystem which reaches 5-10m above sea level.
Size and Shape
As it is man made the wetlands have a quite rectangular shape. There are 100 hectare of parkland in total with 48 hectare of Mangroves.
As it is man made the wetlands have a quite rectangular shape. There are 100 hectare of parkland in total with 48 hectare of Mangroves.
Continuity
The wetland is likely to have been present for around 15 000 years since the Sydney harbour area was flooded by rising sea levels.
The area would also extend far further south were it not hemmed in by urban development.
The wetland is likely to have been present for around 15 000 years since the Sydney harbour area was flooded by rising sea levels.
The area would also extend far further south were it not hemmed in by urban development.
2. Biophysical Interactions
Dynamics and Weather and Climate
Sydney olympic park experiences the temperate sub tropical weather found across Sydney. Storms are common in Summer and Autumn.
However, sea level rises associated with climate change pose a significant threat to the ecosystem.
Sydney olympic park experiences the temperate sub tropical weather found across Sydney. Storms are common in Summer and Autumn.
However, sea level rises associated with climate change pose a significant threat to the ecosystem.
Geomorphic and Hydromorphic Interactions
The gradient of the intertidal area determines where particular plants are located. The tidal reach creates a statified vegetation pattern.
The main geomorphic event affecting an intertidal wetland are the sediment flows as tributaries enter Parramatta River.
The dense anaerobic soils of the mangrove area are flushed twice a day by the tidal movement. Without this flushing, soil acidity builds up from additional Hydrogen Sulfides eventually making the soil toxic.
At higher altitudes tides are only infrequent and the evaporation of salt water results in hypersaline conditions. Only the Sarcocornia quinqueflora can survive in these conditions.
The gradient of the intertidal area determines where particular plants are located. The tidal reach creates a statified vegetation pattern.
The main geomorphic event affecting an intertidal wetland are the sediment flows as tributaries enter Parramatta River.
- Sediment is trapped by mangrove root systems
- Creek water flow is slowed by wetland ecosystem.
- Anaerobic mud soils.
The dense anaerobic soils of the mangrove area are flushed twice a day by the tidal movement. Without this flushing, soil acidity builds up from additional Hydrogen Sulfides eventually making the soil toxic.
At higher altitudes tides are only infrequent and the evaporation of salt water results in hypersaline conditions. Only the Sarcocornia quinqueflora can survive in these conditions.
Biogeographical Interactions
The grey Mangrove (Avicennia Marina) dominates the intertidal area and forms the keystone species. Sarcocornia quinqueflora and Casurina glauca are also key vegetation types. Each of these plant communities has particular tolerances for salinity and waterlogging. This results in distinct statification of vegetation based on tidal reach.
The Grey Mangroves have particular adaptations to the waterlogged and saline conditions. These include:
The Sarcocornia quinqueflora uses a particular growth pattern to collect and extrude salt.
The Casurina glauca trees use allelopathic roots and leaves to prevent the growth of colonising plant species. a
The grey Mangrove (Avicennia Marina) dominates the intertidal area and forms the keystone species. Sarcocornia quinqueflora and Casurina glauca are also key vegetation types. Each of these plant communities has particular tolerances for salinity and waterlogging. This results in distinct statification of vegetation based on tidal reach.
The Grey Mangroves have particular adaptations to the waterlogged and saline conditions. These include:
- Mangrove root systems use cable and fibrous roots. exclude salt
- Pneumatophores with aerenchyma breath during high tide.
- waxy/hairy leaves reduce transpiration
- leaves extrude salt
- vivacious seeds begin growth on plant. float to suitable niche site.
The Sarcocornia quinqueflora uses a particular growth pattern to collect and extrude salt.
The Casurina glauca trees use allelopathic roots and leaves to prevent the growth of colonising plant species. a
Adjustments in Response to Natural Stress
3. The nature and rate of change affecting the ecosystem.
The mangroves species and the intertidal wetland ecosystem are both adapted to change in the form of tides. However, alterations can move the ecosystem beyond its level of resilience.
Rapid Changes
Medium Changes
reshaping of creek hydrology (especially Powells creek).
Introduced species(Cats, Myna birds, Morning Glory vine, Lantana)
River traffic swash (River Cats limited to 4 knots in upper river system).
leakage from historical chemical waste
Growing pressures from population increase in Rhodes/Wentworth Point suburbs
Damage to migratory bird destination wetlands.
Slow Changes
Sea level rise is a major threat to the ecosystems sustainability. Although it may take 100 years, a sea level rise of 50cm is a realistic scenario and would eliminate the Badu Wetlands ecosystem (OzCoasts, 2015).
Rapid Changes
- Tides
- chemical spills (There is a high potential for spills on M4, Parramatta Rd or Centenary Drive).
- Noise Pollution from V8 and Formula 1 races.
Medium Changes
reshaping of creek hydrology (especially Powells creek).
Introduced species(Cats, Myna birds, Morning Glory vine, Lantana)
River traffic swash (River Cats limited to 4 knots in upper river system).
leakage from historical chemical waste
Growing pressures from population increase in Rhodes/Wentworth Point suburbs
Damage to migratory bird destination wetlands.
Slow Changes
Sea level rise is a major threat to the ecosystems sustainability. Although it may take 100 years, a sea level rise of 50cm is a realistic scenario and would eliminate the Badu Wetlands ecosystem (OzCoasts, 2015).
Human Impacts
Climate change (-ve) is likely to be the most devastating human impact on the wetlands. Firstly due to sea level rises making the wetlands uninhabitable and urban growth resulting in the ecosystem being unable to migrate to higher ground. Climate change will also result in more frequent and intense storms in Sydney. This in turn will result in storm damage and greater velocities of run off.
Changes to the hydrology (-ve/+ve with restoration) of Badu were implemented in the 1930s onwards. Firstly, the original shape of Wentworth Bay has been completely altered. Bund walls were installed to prevent tides and commence land reclamation. More recently, the bund walls have been segmented to allow tidal flow to return. A "smartgate" has also been added to the waterbird pond to mimic tidal flow.
Flotsam or floating pollution (-ve) drifting into the mangrove and salt marsh area with the incoming tide is a major source a gross pollutants. Gross pollution is also prone to entering the mangrove area from storm water. Oil spills/hydrocarbon inputs (-ve) are also a threat from the major roads that ring the ecosystem. hydrocarbon pollution is also likely to enter the ecosystem as runoff from road surfaces after storms.
Land clearing in the area has caused damage to local ecology (-ve). The removal of mangroves and salt marsh has had a negative impact on the sites resilience.
Development of the local area (-ve and +ve) has been taking place rapidly since the Olympic games. Although, an urban residential population is preferable to an industrial land use the communities of Wentworth Point and Rhodes have swelled to 2,759 and 5,679 respectively (ABS, 2011) and these people place pressures on the park. Additional population is scheduled to added to Rhodes, Wentworth Point, Concord and Newington in the near future. Additional built area has an impact by creating greater runoff increasing the local predatory pet populations and creating noise and turbidity during construction. Conversely, the largely apartment based population value the park highly as their only available green space. Furthermore the proximity of bushland and native vegetation results in higher property prices which local residents are keen to preserve.
Feral animals and introduced weeds (-ve) are major human impacts in the area. Dogs, cats, foxes are common introduced species. Sydney Olympic Parks Authority also monitors closely for invasive weed species.
The use of the site for education purposes (+ve) adds a growing awareness about this ecosystem and promotes the valuing of the ecosystem. School tours are used, but also signage and images on drains to prompt the public to link the ecosystem to their actions.
In 2011-2012 Sydney Olympic Park hosted 2.7 million visitors, many of whom use the Badu wetlands and surrounding parkland. This Tourism usage (-ve) creates noise and disruption for birds and other fauna. Recreational uses (-ve/+ve) uses for the park such as the V8 Super car race can have a highly detrimental effect. However the valuing of the park creates support for its protection.
Environmental Management (+ve) at Badu and SOPA is both scientific and intensive. The area is a showcase for sustainable urban development and as a result the scientific management of ecosystems is improving and people learn how to manage highly degraded ecosystems.
Changes to the hydrology (-ve/+ve with restoration) of Badu were implemented in the 1930s onwards. Firstly, the original shape of Wentworth Bay has been completely altered. Bund walls were installed to prevent tides and commence land reclamation. More recently, the bund walls have been segmented to allow tidal flow to return. A "smartgate" has also been added to the waterbird pond to mimic tidal flow.
Flotsam or floating pollution (-ve) drifting into the mangrove and salt marsh area with the incoming tide is a major source a gross pollutants. Gross pollution is also prone to entering the mangrove area from storm water. Oil spills/hydrocarbon inputs (-ve) are also a threat from the major roads that ring the ecosystem. hydrocarbon pollution is also likely to enter the ecosystem as runoff from road surfaces after storms.
Land clearing in the area has caused damage to local ecology (-ve). The removal of mangroves and salt marsh has had a negative impact on the sites resilience.
Development of the local area (-ve and +ve) has been taking place rapidly since the Olympic games. Although, an urban residential population is preferable to an industrial land use the communities of Wentworth Point and Rhodes have swelled to 2,759 and 5,679 respectively (ABS, 2011) and these people place pressures on the park. Additional population is scheduled to added to Rhodes, Wentworth Point, Concord and Newington in the near future. Additional built area has an impact by creating greater runoff increasing the local predatory pet populations and creating noise and turbidity during construction. Conversely, the largely apartment based population value the park highly as their only available green space. Furthermore the proximity of bushland and native vegetation results in higher property prices which local residents are keen to preserve.
Feral animals and introduced weeds (-ve) are major human impacts in the area. Dogs, cats, foxes are common introduced species. Sydney Olympic Parks Authority also monitors closely for invasive weed species.
The use of the site for education purposes (+ve) adds a growing awareness about this ecosystem and promotes the valuing of the ecosystem. School tours are used, but also signage and images on drains to prompt the public to link the ecosystem to their actions.
In 2011-2012 Sydney Olympic Park hosted 2.7 million visitors, many of whom use the Badu wetlands and surrounding parkland. This Tourism usage (-ve) creates noise and disruption for birds and other fauna. Recreational uses (-ve/+ve) uses for the park such as the V8 Super car race can have a highly detrimental effect. However the valuing of the park creates support for its protection.
Environmental Management (+ve) at Badu and SOPA is both scientific and intensive. The area is a showcase for sustainable urban development and as a result the scientific management of ecosystems is improving and people learn how to manage highly degraded ecosystems.
Management Strategies
Traditionally, the area was managed by the Wann-gal clan of Eora who used the entire Parramatta River mangrove area to collect food and fibre. There is evidence of use by the Wanngal clan dating back around 20000 years (SOPA, 2014) in the form of camp fire and shell middens. The Wanngal clan would have employed nomadic lifestyles, a strong cultural connection to country and cultural values that permitted only subsistence collection to manage their impact. While traditional management was highly sustainable, its location was one of the first in Australia to be colonised by the european invaders in 1788.
Contemporary management of the area has changed significantly as the locations ecological value has been reevaluated and a philosophy of conservation has slowly replaced the ecological imperialism of the early 1900s.
The area was scheduled for development into industrial use but now is valued for ecological value (…and residential use)
The park enjoys a legal framework for its protection that mixes International agreements (CAMBA, JAMBA, RoKAMBA with commonwealth environmental legislation covering endangered species, such as salt marsh and mangroves. The SOPA has jurisdiction over the Badu intertidal wetlands. Having a single authority is likely to benefit the ecosystem.
Some of the management strategies that have been put in place to address specific challenges include;
Floating pollution boom
Frog fencing.
Modification of bund walls
Leachate network
Concrete capping of pollution dumps
Design of storm water traps to produce ponds that create biodiversity
The area was scheduled for development into industrial use but now is valued for ecological value (…and residential use)
The park enjoys a legal framework for its protection that mixes International agreements (CAMBA, JAMBA, RoKAMBA with commonwealth environmental legislation covering endangered species, such as salt marsh and mangroves. The SOPA has jurisdiction over the Badu intertidal wetlands. Having a single authority is likely to benefit the ecosystem.
Some of the management strategies that have been put in place to address specific challenges include;
Floating pollution boom
Frog fencing.
Modification of bund walls
Leachate network
Concrete capping of pollution dumps
Design of storm water traps to produce ponds that create biodiversity
Evaluation of management
o Traditional Management proved extremely sustainably. However this is no longer possible.
o Contemporary management is only as effective as the will to protect the ecosystem it is. Changes in attitude could make the management of the wetlands more secure or more at risk very quickly. The V8 super cars are a good example of how gradual changes need to be contested.
o International involvement, such as a RAMSAR agreement, places additional requirements on Governments to protect the coastline.
o However, the site remains highly degraded, moreover, there are significant urban pressures on the ecosystem.
o Even if the area is managed excellently into the future, the threat of sea level change may still annihilate the ecosystem.
The verdict: It is a very damaged area that will continue to be on virtual “life support” for long into the future. This ecosystem can only be saved if it continues to be valued by community and government.