Gamay (Botany Bay)
Location
- Approximately 13 km south of the CBD of Sydney
- Approximately 34°S, 151°12'E.
- semi-enclosed, low-flow embayment
- fed by the Georges and Cooks rivers (both freshwater tributaries)
- combined catchment area of approximately 1165 km2
- most of the catchment is drained by the Georges and Woronora rivers.
- Approximately 13 km south of the CBD of Sydney
- Approximately 34°S, 151°12'E.
- semi-enclosed, low-flow embayment
- fed by the Georges and Cooks rivers (both freshwater tributaries)
- combined catchment area of approximately 1165 km2
- most of the catchment is drained by the Georges and Woronora rivers.
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Bathymetry
- average depth of Gamay is 11 m
- much of the bay is significantly shallower at 5 m
- the entrance of the bay is around 25m due to dredging
Activities to explore bathymetry
Access the links below to explore the bathymetry of Gamay.
Fishing App - Nautical charts - version 1
Fishing App - Nautical charts - version 2
- average depth of Gamay is 11 m
- much of the bay is significantly shallower at 5 m
- the entrance of the bay is around 25m due to dredging
Activities to explore bathymetry
Access the links below to explore the bathymetry of Gamay.
Fishing App - Nautical charts - version 1
Fishing App - Nautical charts - version 2
Cultural Significance
Access pages 40 and 41 of the Sea Country Plan to view cultural sites in Gamay.
Access pages 40 and 41 of the Sea Country Plan to view cultural sites in Gamay.
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Gamay (Botany Bay) Comic
Gamay (Botany Bay) is a site of great cultural and ecological significance. It is highly industrialised and urbanised, and has been extensively modified. Despite this, it contains a diverse range of natural habitats: seagrass, beaches, mangroves, salt marshes, oyster reefs, rocky shores, rocky reefs and open water. Ramsay-listed, Towra Point Nature Reserve is located in along the southern shore of Gamay, and is an important site demonstrating the interconnections between different habitats. It is especially important for migratory birds who feed and rest there after vast journeys, and as a critical nursery ground for fish. Download the Gamay comic |
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Hydrological Processes - Mapping Activity
Download the Gamay - Hydrological Processes mapping activity |
Biodiversity in Gamay
Biodiversity in Gamay
Key terms
Biodiversity: biological diversity in an environment as indicated by numbers of different species of plants and animals.
Polycheates: a diverse group of segmented worms that live primarily in ocean habitats.
Crustaceans: invertebrates with a hard exoskeleton, a segmented body that is bilaterally symmetrical, and more than four pairs of jointed appendages
Molluscs: soft-bodied invertebrates, usually wholly or partly enclosed in a calcium carbonate shell.
Echinoderms: invertebrate marine animals, characterized by a hard, spiny covering or skin.
Mammals: any animal in which the female gives birth to babies, not eggs, and feeds them on milk from her own body
The Australian Museum’s electronic database provides information about specimens collected by latitude and longitude. Information from specimens collected in Gamay:
Read more...
Key terms
Biodiversity: biological diversity in an environment as indicated by numbers of different species of plants and animals.
Polycheates: a diverse group of segmented worms that live primarily in ocean habitats.
Crustaceans: invertebrates with a hard exoskeleton, a segmented body that is bilaterally symmetrical, and more than four pairs of jointed appendages
Molluscs: soft-bodied invertebrates, usually wholly or partly enclosed in a calcium carbonate shell.
Echinoderms: invertebrate marine animals, characterized by a hard, spiny covering or skin.
Mammals: any animal in which the female gives birth to babies, not eggs, and feeds them on milk from her own body
The Australian Museum’s electronic database provides information about specimens collected by latitude and longitude. Information from specimens collected in Gamay:
- 10,985 speciment in total
- 429 species of polycheates
- 580 crustaceans
- 802 molluscs
- 76 echinoderms
- 272 fishes
Read more...
Photos: Jane Herring
Wild Sydney Harbour and Gamay Rangers work together to study marine mammals in Gamay. It is home to an exciting number of marine mammals, including dolphins, seals, whales, and even the occasional dugong. Further research is needed on how many there are, when they come, how they move through the bay, and their behaviours. Knowledge is gained through storytelling that has been passed through from generation to generation.
Access the Gamay Rangers website.
Article: Gamay Indigenous rangers help scientists study wildlife moving through heavily industrialised Botany Bay
The Gamay Sea Plan used community consultation to identify species in Gamay. View page 25 to see the list of species identified.
Access the Gamay Sea Plan.
Another important source of information comes from photography of scuba divers. The Leap, The Steps and Bare Island are a popular diving sites. The Reef Life Survey involves volunteer divers conducting underwater surveys.
Access the Gamay Rangers website.
Article: Gamay Indigenous rangers help scientists study wildlife moving through heavily industrialised Botany Bay
The Gamay Sea Plan used community consultation to identify species in Gamay. View page 25 to see the list of species identified.
Access the Gamay Sea Plan.
Another important source of information comes from photography of scuba divers. The Leap, The Steps and Bare Island are a popular diving sites. The Reef Life Survey involves volunteer divers conducting underwater surveys.
Biodiversity Fieldwork
Dipnetting
Using a dip-net, a plastic container and an identification chart you can undertake a biodiversity survey. In the container on the left there was a squid, fish and various types of whelk that needed to be identified using the ID chart.
Using a dip-net, a plastic container and an identification chart you can undertake a biodiversity survey. In the container on the left there was a squid, fish and various types of whelk that needed to be identified using the ID chart.
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Examples: Pipefish
These animals have a fused jaw and suck their prey up through their mouth. They eat small crustaceans. Their skin is made up of overlapping bony plates which give them some protection against predators. The tails of sea horses and pipefish are prehensile (it can grasp) allowing them to hold onto seagrasses in fast flowing water (e.g. tides). |
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Examples: Soldier crabs
These crabs live on the tidal mudflats. Their bodies are more rounded than most crabs to enable them to move forwards rather than sideways. The crab has a chamber in the thorax which contains the gills and lungs. They also have a hole in the front part of their shell. This enables the crabs to access air both in and out of water.to edit. |
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Student Activities
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Human Impacts - Threats
Caltex Oil Refinery The oil refinery produced petrol, jet fuel, butane and a range of other products. There was a real risk of tankers spilling oil into the Bay, and this happened several times. In 1979 there was a major oil spill in the area which had a width of approximately 3km. This affected 100ha of mangroves. The refinery was also permitted under law to release a range of emissions including groundwater, water pollution and sludge among other things. The refinery closed in 2014. The site has now been decommissioned and sections demolished. 14 process units, 4 power plants, 67 above and below ground tanks and electrical services, pipeways and utilities have been removed. Airport The airport is located opposite Towra Point Wetland on the northern side of Botany Bay. The area consists of a great deal of cement (an impermeable surface), meaning that any runoff carries with it oils and jet fuel directly into the bay. In addition, the noise of the aircraft flying overhead disturbs the migratory birds that use Towra Point as a breeding ground. In the 1990s a third runway was constructed. The construction and dredging required to create the third runway resulted in a significant decline in the amount a seagrass in Botany Bay. This also resulted in the reclamation of shorebird habitat (such as that for the Little Tern), and resulted in a decline of some migratory birds in Towra Point in the same period. Sediment deposition and the speed of waves were also affected by the creation of the third runway. Wave refraction off the hard surface of the third runway has increased the speed of water hitting sections of Towra Beach. More recently, the airport has funded habitat restoration projects and community groups involved in environmental monitoring and protection. Industrial development A wide range of industrial activities have caused damage to Botany Bay and Towra Point Wetlands. Historically tanning and wool scouring occurred in the area because they were isolated from the original settlement in Port Jackson/Sydney Harbour. The area was first used as a port in 1880 and sand-mining began in the 1930s. In the 40s and 50s Boral and the Australian Oil Refinery began using the bay to transport oil. During the 70s there was extensive dredging and land reclamation around the bay. Sand-mining, toxic chemicals discharge and dredging changed the shape and chemical composition of the bay. Orica Companies such as Orica have contaminated groundwater and the sands aquifer below the wetlands with chemicals. Orica has also had a similar impact on Homebush Bay Wetlands. Residential development Residential areas reduce the areas available for natural vegetation, change natural water flow and increase local population pressure. Ornamental gardens in yards also provide a threat as invasive weeds can escape from gardens and compete with native vegetation. Groynes These artificially constructed sea walls trap sand being carried inland by the waves. Most of these sea walls were constructed during the 1960s and 70s and were a response to beach erosion along Silver Beach.This is particularly an issue as Towra Beach is eroding and this cuts off a source of sand to replenish sand on Towra Beach. Creeks and stormwater Stormwater run-off from residential areas can contain fertilisers, pesticides, oils and chemicals such as paint, etc. This run-off enters the bay and can impact on the floral and faunal aquatic species living there. It can change the pH of the water (acidity and alkalinty). Fertilisers can result in an increase of phosphorous in the water and cause algal blooms. Oils and chemicals can smother aquatic plants and animals. This makes it difficult for plants to photosynthesise and can make it difficult for birds to fly and frogs (and other amphibians) to breathe. Canal developments Waterfront canal housing developments like Sylania Waters clear wetlands, change river banks to hard impermeable surfaces, and increase population pressure close to the river and bay. Golf courses and recreational parkland Golf courses and other forms of recreational parkland create somewhat of a buffer between the bay and residential and industrial land uses. However, these land uses involve the clearing of natural vegetation resulting in increased run-off (compared to natural vegetation) and reduced habitat areas. Natural vegetation is replaced by grasses such as Kikuyu. Efforts to keep the grass green and of a good playable standard result in the use of fertilisers which can flow into the bay or nearby creeks. Sewage treatment plant Sewage overflow in rainy periods can result in untreated sewage entering Botany Bay. This contains high levels of nutrients and can result in algal blooms as a result of eutrophication. Pathways and pathway erosion Pedestrian movement in and around the Towra Point Nature Reserve creates pathways avenues of erosion. Pedestrians who don't stay on the pathway will trample and kill plants, making the pathway wider. Horse stables Nearby Horse stables provide a risk of horses trampling on vegetation as they walk through the surrounding area. It is possible that their droppings may contain duttings or seeds of invasive plants. Boating The use of recreational boats in the bay results in damage to aqautic vegetation and increased rates of erosion. The propellers on boats chop up sea grass in shallow water. This can have a long-lasting impact as seagrass take a long time to recover from disturbances. High spedd boats and sea craft such as jet skis create wash (waves caused by the boat) which causes erosion along the beaches. |
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Human Impacts - Fieldwork Planning Activity
Construct a log of events and activities to manage the development of a fieldwork activity explaining human impacts on Towra Point Wetlands.
To do so you must complete the following:
- Hypothesise what the human impact are that impact on Towra Point Wetlands (do this by referring to your readings). Create a list of 4-5 human impacts.
- Consider the types of fieldwork which will enable you to examine these human impacts. Choose 5 different fieldwork techniques. You might like to revise how to carry out these techniques.
- Create a timeline of events outlining what tasks you will carry out and what you expect to find out. Consider the timing - as you won't actually be carrying out these activities (they are hypothetical at this stage) you may choose to conduct the activities over a long period of time (stick to within one year).
- Collect satellite imagery of Towra Point Wetlands. Annotate the image with information about where you will conduct the fieldwork.
- Use satellite imagery to create a précis map which shows the spatial pattern of overland flow running into Botany Bay.
When you have completed your log of events write a 200 word response which outlines your expected results.
Construct a log of events and activities to manage the development of a fieldwork activity explaining human impacts on Towra Point Wetlands.
To do so you must complete the following:
- Hypothesise what the human impact are that impact on Towra Point Wetlands (do this by referring to your readings). Create a list of 4-5 human impacts.
- Consider the types of fieldwork which will enable you to examine these human impacts. Choose 5 different fieldwork techniques. You might like to revise how to carry out these techniques.
- Create a timeline of events outlining what tasks you will carry out and what you expect to find out. Consider the timing - as you won't actually be carrying out these activities (they are hypothetical at this stage) you may choose to conduct the activities over a long period of time (stick to within one year).
- Collect satellite imagery of Towra Point Wetlands. Annotate the image with information about where you will conduct the fieldwork.
- Use satellite imagery to create a précis map which shows the spatial pattern of overland flow running into Botany Bay.
When you have completed your log of events write a 200 word response which outlines your expected results.
Human Impacts - Habitat Restoration
A range of habitat restoration projects are currently being implemented in Gamay and along the Georges and Cooks Rivers:
A range of habitat restoration projects are currently being implemented in Gamay and along the Georges and Cooks Rivers:
Management
International Agreements
JAMBA - Japan-Australia Migratory Bird Agreement
CAMBA - China-Australia Migratory Bird Agreement
RAMSAR - Convention on Wetlands of International Importance.
ROKAMBA - Republic of Korea-Australia Migratory Bird Agreement
Convention on the Conservation of Migratory Species of Wild Animals (CMS/Bonn Convention, 1979)
Convention on Biological Diversity (CBD, 1992)
London Convention and London Protocol on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter
United Nations Framework Convention on Climate Change (UNFCCC) and Paris Agreement
Commonwealth - Policies and Acts
Environment Protection and Biodiversity Conservation Act 1999
Australian Ramsar Management Principles
NSW - Policies and Acts
State Environmental Planning Policy (Biodiversity and Conservation) 2021
State Environmental Planning Policy (Resilience and Hazards) 2021 – Chapter 2 Coastal Management
Coastal Management Act 2016
NSW Coastal Management Manual
NSW Coastal Design Guidelines 2023
Marine Estate Management Strategy 2018–2028
NSW Fisheries / DPI fisheries and aquatic habitat management policies and regulations
NSW Wetlands Policy
NSW Plan for Nature (2024)
Saving our Species – Biodiversity Conservation Program
NSW Coastal Waters Marine Pollution Plan
Regional, Local, Cathment - Policies, Plans, etc
Towra Point Nature Reserve Plan of Management (2001)
Towra Point Aquatic Reserve management framework / management rules
Sutherland Shire Local Environmental Plan 2015 (Sutherland LEP 2015)
Sutherland Shire Development Control Plan 2015
Sutherland Shire Local Strategic Planning Statement
Sutherland Shire Catchment and Waterways Strategy 2025–2035
Georges River Coastal Management Program – Stages 2–4, including Botany Bay
Botany Bay–Port Hacking Marine Emergency Sub Plan
Botany Bay Precinct Emergency Sub Plan
International Agreements
JAMBA - Japan-Australia Migratory Bird Agreement
CAMBA - China-Australia Migratory Bird Agreement
RAMSAR - Convention on Wetlands of International Importance.
ROKAMBA - Republic of Korea-Australia Migratory Bird Agreement
Convention on the Conservation of Migratory Species of Wild Animals (CMS/Bonn Convention, 1979)
Convention on Biological Diversity (CBD, 1992)
London Convention and London Protocol on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter
United Nations Framework Convention on Climate Change (UNFCCC) and Paris Agreement
Commonwealth - Policies and Acts
Environment Protection and Biodiversity Conservation Act 1999
Australian Ramsar Management Principles
NSW - Policies and Acts
State Environmental Planning Policy (Biodiversity and Conservation) 2021
State Environmental Planning Policy (Resilience and Hazards) 2021 – Chapter 2 Coastal Management
Coastal Management Act 2016
NSW Coastal Management Manual
NSW Coastal Design Guidelines 2023
Marine Estate Management Strategy 2018–2028
NSW Fisheries / DPI fisheries and aquatic habitat management policies and regulations
NSW Wetlands Policy
NSW Plan for Nature (2024)
Saving our Species – Biodiversity Conservation Program
NSW Coastal Waters Marine Pollution Plan
Regional, Local, Cathment - Policies, Plans, etc
Towra Point Nature Reserve Plan of Management (2001)
Towra Point Aquatic Reserve management framework / management rules
Sutherland Shire Local Environmental Plan 2015 (Sutherland LEP 2015)
Sutherland Shire Development Control Plan 2015
Sutherland Shire Local Strategic Planning Statement
Sutherland Shire Catchment and Waterways Strategy 2025–2035
Georges River Coastal Management Program – Stages 2–4, including Botany Bay
Botany Bay–Port Hacking Marine Emergency Sub Plan
Botany Bay Precinct Emergency Sub Plan
Revision questions
Towra Point Nature Reserve Revision
- Describe the geographical location of Gamay.
- Describe the different sources of information used to learn about biodiversity in Gamay. Why are different information sources required?
- Who are the Gamay Rangers? What is their relationship with Gamay and with other initiatives in the bay?
- What are the important habitats located in Gamay?
- Choose one endangered species found in Gamay and create a species profile. Provide a description of the species - what it looks like, where it is located, threats to the species. Include an image and map.
- What are the threats to the seagrass Posidonia australis?
- What efforts are being made to restore Posidonia australis?
- What is the name of the part of the mangrove roots that protrudes above the water's surface?
- What are JAMBA and CAMBA and what are their key points?
- When was the RAMSAR convention signed?
- What are the main aims of RAMSAR?
- Describe a link between the hydrosphere and lithosphere in intertidal wetlands.
- Describe a link between the biosphere and the atmosphere in the intertidal wetlands.
Towra Point Nature Reserve Revision
- Describe the location of Towra Point. Include a map.
- List 2 pieces of legislation (Acts) which provide for the protection of Towra Point.
- Name 5 community groups involved in protecting Towra Point wetland.
- What is the "Elephant's Trunk", and what are the issues associated with it?
- Describe 3 human impacts on Towra Point.
