Dulwich Hill is a suburb located in Sydney's Inner West, surrounded by Summer Hill, Hurlstone Park, Marrickville, Petersham, Lewisham and Earlwood. It experienced growth in the late 1800s following the introduction of the tram line, and as a result contains buildings with heritage architecture, particularly Federation architecture.
The tram line through Dulwich Hill was not in use as public transport from the 1950s. The Inner West light rail extension in 2013 reconnected Dulwich Hill by rail with nearby suburbs and the city. For more details see my previous post Inner West Light Rail Extension.
For more information about the history and development of Dulwich Hill, visit the Dulwich Hill section of the Marrickville historical society - Dulwich Hill - a history.
The Sydenham to Bankstown Urban Renewal Strategy, encompasses the suburb of Dulwich Hill, rezoning for higher density and redevelopment of older buildings. Changes to zoning as part of this strategy can be seen on the Planning NSW website - Dulwich Hill Landuse Plan. The plan for Dulwich Hill includes 2000 more dwellings, with 3 storey development along Wardell Road, and unit developments from 3-5 storeys near the Dulwich Hill station. Higher density housing developments are zoned for around the Dulwich Hill light rail station (between 3-7 storeys). 8 storey developments will be allowed around Arlington Grove Light Rail station.
View the Changing Places - Sydenham to Bankstown Urban Renewal Precinct post.
The Save Dulwich Hill Community Group promotes issues related to the redevelopment of the suburbs and lobbies the government to preserve the heritage of suburb. Visit the Save Dully website to read more about their actions.
The NSW Government has released a revised Sydenham to Bankstown Urban Renewal Strategy for public comment. The strategy will be implemented over 20 years and sees plans for urban consolidation and retail opportunities along the a new metro line which will replace the existing train line and link with the Metroline being built in Sydney's north west. It includes the creation of over 35,000 new homes. View the Sydenham to Bankstown Urban Renewal Corridor website.
Priority Precincts where development will be concentrated include Campsie, Canterbury, Lakemba and Belmore. Developments in these areas will include buildings up to 25 storeys high. Marrickville will have an increase in homes of 84%, while Canterbury will increase by 208%. and Belmore will increase 128%. Some suburbs such as Dulwich Hill and Hurlstone Park have had a reduction in the number of new dwellings proposed compared to the previous plan released.
View Changing Places: Conflict over development in Dulwich Hill.
The existing rail line between Sydenham to Bankstown will be converted to a Metro line. During construction the rail line will not be in operation. It is anticipated that once completed, it will reduce wait times and travel times to the city. However, the existing rail line allows commuters to connect with the existing CityRail network and travel to locations such as Chester Hill, Villawood, Cabramatta and Liverpool, without having to change trains. Commuters can then change trains to connect with the rest of the CityRail network. It is unclear at this stage how the Metro line will interact with the existing City Rail and light rail networks.
Residents and community groups have expressed some concerns regarding the increased level of density and population. Concerns relate to inadequate parkland and open space, destruction of heritage architecture, new designs which are unsympathetic to the heritage nature of suburbs, and lack of supporting infrastructure. There has been limited information released regarding industrial and commercial zoning, and concerns have been raised regarding the sustainability of the development. The rezoning will also take place years before the Metro line will finished. Supporters of the developments state that high density is better for the environment than urban sprawl and increases connectivity and land values in the area.
The renewal strategy announcement has come at a time when residents of the Inner West are already dealing with a large number of new developments and there is a perception that there is an inequitable system of planning in place. For example Council targets for new housing approvals have been exceeded in Canterbury, but many other council areas such as Hunters Hill, Warringah, Pittwater, Willoughby and Manly have not met their targets.
There have been a range of issues associated with the WestConnex development such as compulsory acquisition and demolition of houses, encroaching on parks, noise and construction issues. The recently announced future sale of Canterbury Racecourse for development has also been an issue of contention. These issues combined are likely to make Inner West residents less persuadable when it comes to future developments.
Residents, ex-pollies baulk at high density in revised Sydneham to Bankstown Urban Renewal Strategy.
Planning experts say development should be embraced and not feared along Sydenham to Bankstown corridor.
Sydney's tale of two suburbs: new analysis shows the wide spread of development.
Metro's on the wrong track
High rise to hell
Open season on high rise
Heritage, character face destruction
Inner West needs nine new schools
You have been given the job of designing a new city. It will be located at Warnervale on the Central Coast between the M1 and the Pacific Highway. The aim of your city design is to plan the most liveable city possible.
Task 1: Brainstorm your ideas and begin planning.
Create a list or mind map of all the features that your city will need. At this stage you are just coming up with ideas. You may change your mind as your city design develops.
Task 2: Design your city plan
You have been provided with an outline map. Use your mapping rules to begin designing your city. Include border, orientation (north point), a legend, a map title and scale. On your map label the M1 motorway, Sparks Road and the railway line. Draw and label all the key features of your city.
Task 3: Draw your CBD and a residential area.
Construct sketches of how you imagine your city will look like. Annotate your images with important features of your city (style of building, tree-lined streets, community spaces, retail spaces, etc).
Task 4: Create a prospectus
Write a report that addresses how you have created a "liveable" city. Refer to the questions outlined in Task 1 to help you structure your response. Scan your city plan and CBD and residential area drawings and include them in your prospectus.
There is a huge amount of information available about coral reef health and in particular the mass coral bleaching events that have occurred over the past two years. Two of my previous posts are linked below, but if you scroll to the bottom of the page there are a range of other articles, reports and websites regarding coral bleaching that you might find useful.
Mass coral bleaching events
Coral bleaching - reef resilience
Students should define the following key terms:
- natural selection
Answer the questions below. Conduct internet research to find articles and reports which support your answers.
Coral bleaching - GBRMPA
Coral bleaching and the Great Barrier Reef - ARC CoE
Coral bleaching: Extreme heat pushes parts of the Great Barrier Reef beyond recovery - ABC
Coral bleaching events - AIMS
Great Barrier Reef: a "hopping hotspot" - Australian Geographic
The changes in temperature and associated bleaching are resulting in a different mix of species on the reef. This will impact reefs in the long term.
Loss of species
Fish, whales, dolphins, sharks, rays and the many other organisms found in reefs rely on the complexity of the ecosystem for survival. Some fish rely on the colour of the corals for camoflauge and the structure of the coral for hiding. Many organisms are unable to carry out normal functions and processes as a result of the increased ocean acidification associated with climate change. Shellfish are less able to create their shells due to increased pH. Slow growing corals will take 100-200 years to recover, meaning that the reef will not exist in the form that we have known it in the past.
Dispersal of spawn
Ocean warming impacts on the dispersal or coral spawn (eggs). Increased ocean temperatures result in a decline in the dispersal distance of coral spawn from the origin (parent coral) to the destination site. This change in dispersal patterns can impact on species' distribution, abundance or corals in particular areas and genetic diversity across reefs. Changes to dispersal patterns can also impact on the connectivity (interconnections) between different areas of the reef by limiting the areas of reef that particular coral species are located.
Poleward shift of species
Ocean warming can also result in a poleward shift of species from tropical zones to more temperate zones. Warmer waters are found further from the tropics and species are able to take advantage by increasing their range.
In Western Australia, a species of wrasse - cheorodon rebuscens has started to shift its range with displacement of recruits south of its usual habitat. There is evidence of high recruitment at the temperate edge and no recruitment at the tropical edge. The range shift provides limited expansion opportunities, reducing resilience of the species.
Irukandji are migrating further south on the Great Barrier Reef as a result of warmer waters and are also having longer seasons in other areas. There have been anecdotal reports of increases in reports of stinging and hospitalisations on islands within the Great Barrier Reef (e.g Fitzroy Island) and snorkellers are being strongly advised to wear stinger suits outside of usual peak Irukandji seasons. Irukandji and associated stingings have also been reported on western side of the southern tip of Frazer Island where they haven't previously been found.
Following bleaching events or even natural disasters, corals can become overgrown with algae, making it difficult for coral recruits to settle and grow. The mix species on a reef can impact on how resilient that particular reefs is. For example in Moorea in French Polynesia experienced high coral mortality in the 1980s. Recovery of the reef was enabled in part as a result of grazing fish such as parrot fish removing some of the algae in the process of eating corals. In this way the biodiversity of the reef contributed to high levels of resilience on the reef in comparison to some other reefs globally. The scale of the bleaching on GBR make it unlikely that these types of natural processes will have much of an impact on recovery.
Below: A parrot fish on the outer reef, 2015.
I had the pleasure of hearing Professor Terry Hughes present as part of the Sydney Ideas talks being run by the University of Sydney. Professor Hughes is Centre Director at the ARC Centre for Excellence for Coral Reef Studies at James Cook University. I use the term "pleasure" because I am a big fan of his work, and think that some of the visual representations that he has created have been incredibly powerful in explaining coral bleaching to students, but actually the information presented was really quite depressing.
Image left: Photograph of bleached corals at Fitzroy Island April 2017.
Hughes described some of the main drivers of degradation of coral reefs: pollution, overfishing and climate change. He explained how overfishing had resulted in the reduction of stock sizes for different species in the past century, how pollution from inland activities resulted in coral mortalities and encroachment of different ecosystems like mudflats in areas previously thriving with corals. He went on to say that the scale and extent of these changes were being dwarfed by the immediate and irreparable changes being wrought by back to back bleaching events.
Below right: Bleached coral on Fitzroy Island April 2017.
Mass bleaching events have occurred in both 2016 and 2017 as a result of increased ocean temperatures. The bleaching is as a result of corals expelling their symbiotic algae. Coral bleaching tends to occur after the summer temperature maximum, and relates to where the hottest water is. In 2016 coral bleaching severely bleached the northern third of the Great Barrier Reef, the middle section was bleached to a lesser extent, but still quite severely, while the bottom third of the reef largely escaped bleaching in 2016. This was established by the surveying of 1160 reefs through 9000km of aerial surveys, and 75 hours of flying. The 2017 bleaching event impacted the central section of the GBR, while the bottom third is again largely unbleached. Cycle Debbie, a chance weather event, lowered temperatures in the southern part of the reef, which contributed to reducing bleaching in this section. The combination of both the 2016 and 2017 bleaching events has been extremely damaging.
There have been reports that the recent cyclone that affected Queensland, Cyclone Debbie may play a role in reducing the impact of coral bleaching. It was reported in the Cairns Post that the cyclone would reduce ocean temperatures, bring cooler waters to the surface and increase cloud cover, thus reducing bleaching, providing stressed corals with an opportunity to recover. The Cairns Post reported that temperatures off Lizard Island had dropped by three degrees and that this would reduce the severity of bleaching. It also provided quotes from a free diver describing the amazing colours and marine life of the outer reef. In reality, as already stated Lizard Island and the top third of the Great Barrier Reef were already severely affected by bleaching in 2016 (well before Cyclone Debbie) and were again affected in 2017. In any case, the path of the cyclone was too far south to have any real impact on areas severely affected by bleaching.
Will the Great Barrier Reef recover?
There is a narrow opportunity for limited recovery, but the Great Barrier Reef as we know it (complexity, extent, etc) is already dead in many areas. It will continue to exist but with reduced biodiversity.
Any real opportunities to protect the reef as it remains is reliant on halting temperature increases and stabilising the climate through reducing reliance on fossil fuels. With negotiations underway between the Australian Government and Adani for for the creation of the Marmichael mines this seems highly unlikely.
For more detail on coral bleaching see my article in this term's GTA NSW HSC edition of the Bulletin.
Symbiosis is a long term relationship between two organisms. There are three types of symbiotic relationship: mutualism (where both organisms benefit), commensalism (where one species benefits, but there is no benefit or harm to the other species), and parasitism (where one organism benefits tot he detriment of the other). There are many examples of symbiosis on coral reefs.
Corals and zoozanthallae
The relationship between the corals and the zoozanthallae is beneficial to both. Corals provide the zoozanthallae with an environment suitable for survival. It is moist and the coral's waste gives energy to the zoozanthallae. Through the process of photosynthesis the zoozanthallae produce compounds that the coral use for food.
Clownfish and Sea Anemones
The Sea Anemones have tentacles with stinging cells. These stinging cells kill many organisms and it is in this way the anemones get their food. Clownfish hide in amongst the tentacles of the Sea Anemone, but are not harmed by them. In this way the clownfish are protected from other predators. Occasionally the Clownfish will catch food for the Sea Anemone.
Sharks and Remoras
Sharks sometimes get parasites which live on the external surface of the shark. Remoras are cleaner fish, and they attach themselves to the shark and kill the parasites. When the shark feeds the Remora are able to eat the scraps from the feed.
Watch the videos below, and take notes about the following symbiotic relationships:
- Christmas tree worms and porites corals
- Coral shrimps and corals
- Goby shrimp and Hawaiian Shrimp Goby
- Cleaner Wrasse and cleaning stations
•Coral Reefs support a large number of plants and animals.
•Coral Reefs are built by millions of tiny animals called polyps.
•Some coral polyp species receive more than 60% of their food from algae.
•Each coral colony begins life as a single polyp, which then reproduces itself as a single polyp, which then reproduces itself by budding or by dividing.
Types of coral reefs
There are eight main categories of corals: branching, corals with meandering ridges and valleys, massive or thick colonies, thin plates and crusts, solitary/isolated/free-living corals, coral with large, daytime expanded polyps, column corals and blue/fir/organ pipe/lace corals. Some examples of coral are found below:
Where are coral reefs found?
Special conditions are needed for reef-building corals. Coral reefs will only grow in waters warmer than 18oC, and no deeper than 50metres. Therefore coral reefs are limited to clear, shallow tropical seas found either side of the equator. Corals may not develop properly in waters that receive freshwater runoff or sediments from rivers.
Deputy Principal at a Sydney high school. Coordinating author of the new Geoactive book series.
7-10 Geography pages have been retired due to the introduction of the new syllabus. The above links relate to current NSW syllabuses. All Commerce resources have been moved onto this main site (search Commerce below).