November 2, 2024

What Does Urbanization Mean for Melbourne’s Platypus?

Brendan Cohen at the start of his Yarra River kayaking journey in the town of Warburton. © Brendan Cohen

I left home long in the past dawn and am now driving north-east into the misty, grey-hued silhouettes of the Victorian Yarra Ranges. I pull over in the town of Warburton, park on the banks of the Yarra River and carry my kayak down to the waters edge.

The morning dew fogs my windshield as I drive down the highway, and the wind whistles as it swirls and wraps over the intense blue kayak connected to the roofing system of my automobile. My hands grip the wheel tightly as I turn my head and peer through my side window, checking to see if my paddles are still connected.

I am on an objective to examine if Melbournes freshwater environments, and the platypus that occupy these waterways, can make it through amidst the spread of urbanisation. As the quality of the Yarra River catchment decreases due to threats such as land cleaning and stormwater, platypus are being required to move further upstream or face termination. Today Im traveling that exact same journey in reverse, from the Yarras source to the sea.

This story is part of a series developed to present the viewpoints of alumni from the National Geographic Society and The Nature Conservancys international youth externship program. Each visitor author is an emerging leader in preservation and storytelling.

The Yarra River

In 2021, a Victoria-wide platypus eDNA study found that the Yarra River catchment showed a clear gradient of decline in platypus numbers towards the lower reaches that are more urbanized. Research by CESAR found that when compared to historical data, the Yarra River has actually experienced a 38% decline in the length of waterways approximated to be inhabited by platypus.

Riparian vegetation, the plants and trees that grow on the banks of the rivers edge, are really essential for freshwater communities. It helps to stabilise banks from erosion, filter sediments, keep soil nutrients, improve general water quality and lower the speed of surface area water overflow into the streams.

Become An Extern.

A research study conducted by University of New South Wales discovered that, over the past 30 years, the area inhabited by platypus has shrunk by a minimum of 22%, or about 200,000 square kilometers, which is a location the size of the entire state of Nebraska. In the last 10 years alone, 41.4% of sub-catchments no longer have records of platypus. This danger will only increase with population development.

As the sun increases over the valley, the Jurassic-like beauty of the surrounding forest begins to come alive. A sense of calm comes over me as my bright blue kayak pieces through the cool water, swaying in tune to the current.

The rivers source lies far to the northeast, where I introduced my kayak, and it streams for more than 240 kilometres all the method down to the mouth of Port Phillip Bay. The Yarra River catchment supports more than one-third of all Victorias native plants and animal types, including the platypus.

My hope is that our iconic platypus can not only flourish but endure in all parts of the Yarra River catchment. By bring back and maintaining the entire river system, we can make sure a sustainable future where both humans and wildlife can exist together.

indicate standing in a storm drain with a kayak.
Brendan Cohen standing in one of Melbournes notorious city streams, Gardiners Creek, Yarra River catchment. © Brendan Cohen.

Yarra River passing through Melbournes CBD. © Andy Wang/ Unplash.

But in city environments, these macroinvertebrates get swept away in abnormal flood events, starving platypus of their primary food source. Stormwater is likewise responsible for further weakening river banks, fragmenting populations, and can flood and damage platypus burrows.

As I take a trip further and even more downstream, I cant assist but discover a reduction in the amount and quality of plant life on the Yarras banks. Previously today I was enveloped by large trees and brilliantly coloured bushes, the air tinged with the scent of eucalyptus. After a couple of hours of paddling, Im now surrounded by turf fields and agricultural pastures.

Gardiners Creek, Yarra River catchment going through a highway underpass. © Brendan Cohen.

The question stays: What is causing their numbers to decline? How precisely is urbanisation impacting the platypus and their habitat? The response to those concerns lies even more downstream.

The Florida manatee is facing extinction due to excessive nutrients washing into the rivers from urban stormwater, farming runoff and wastewater, triggering unsafe algal blossoms that eliminate their primary source of food, seagrass. In Kerala, India, city expansion has caused serious contamination, degrading wetland environments and minimizing the abundance of fish. This has actually negatively impacted regional kingfisher populations, resulting in a decrease of kingfisher types that are belonging to the area and depend on these wetlands for migration.

You can likewise join community groups and council-run programs to help plant native plants along the river banks. Install rain gardens into your back garden which help to catch, filter and disperse stormwater into the soil rather than into our drain system. Smart Water tanks are likewise a fantastic way to assist record rainwater, lowering the amount of stormwater that goes into our catchment, while saving water and even reducing the water expenses.

Yarra River as it goes through the town of Yarra Glen, well-known for its wineries and vineyards. © Brendan Cohen.

River of mists, the Yarra River in the town of Templestowe. © Brendan Cohen.

We were charged to look into an issue affecting our regional freshwater environments which led me to wonder: whats taking place to the platypus? Since of this, many Australians are not conscious of the obstacles platypuses deal with in urban environments.

Platypus play an essential role in freshwater ecosystems as a keystone peak predator, making sure to keep the environmental food chain in balance. Then the platypus is forced to pull back upstream to leave the disruptive conditions or pass away, if there are no macroinvertebrates or healthy vegetated banks. If this happens, entire ecosystems will crash and fall out of equilibrium, something that will continue as Melbourne expands its metropolitan footprint into platypus habitat.

After numerous hours of paddling, passing different creeks and adjacent rivers, Im now about 10 kilometers away from Melbournes CBD. The once-clear water has altered into a threatening brown shade. A plastic bottle wrapped in blue passes me on my left, my brain skips a beat thinking it had come from my kayak.

No matter where you live, what takes place on land flows down into our freshwater ecosystems and affects our wildlife.

How You Can Help Platypuses.

It also provides 70% of Melbournes drinking water, and 30% of Victorians population lives in the Yarra River catchment. To indigenous Aboriginal communities, this river holds terrific spiritual and cultural significance, a place central to their identity, culture, and livelihood. The Wurundjeri people understand the river as the “Birrurung,” which equates to River of Mists.

I motivate everyone to go outdoors and check out nature, who understands, maybe you too may find something interesting about your native wildlife.

Platypus Under Threat.

As the quality of the Yarra River catchment declines due to threats such as land clearing and stormwater, platypus are being forced to move more upstream or face extinction. The Yarra River catchment supports more than one-third of all Victorias native plants and animal types, including the platypus.

Discover the preservation work of other externs from Colombia, the Maldives, and the United States in Nature Conservancy Magazine.

The platypus family (Ornithorhynichidae) are approximated to have lived here in Victoria for the last 120 million years, yet now their survival has actually entered concern. The International Union for Conservation of Nature acknowledges the platypus as a Near Threatened species. Their status differs in various Australian states: in South Australia theyre thought about Endangered, and here in Victoria they were noted as Vulnerable in 2021.

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At the end of my journey, the river has changed from stunning and wild to more familiar. I finish my paddle in Melbournes CBD, surrounded by high skyrises, drifting bars, and countless commuters, all bustling and hectic, a sensory overload. My intense blue kayak no longer feels foreign to the environment. Im careful not to get sidetracked and fall into the water, as this section of the river is prohibited to swim in due to high contamination levels.

Without native riparian vegetation, river banks end up being degraded and weak, which prevents a platypuss capability to create burrows and raise young. Australians can get involved in person science chances such as reporting platypus sightings, which help academics and researchers better understand platypus population sizes, hazards, and distributions.

Everything in nature is connected, and like the platypus we are part of freshwater environments. Australians can get involved in resident science opportunities such as reporting platypus sightings, which help academics and scientists much better understand platypus population hazards, sizes, and circulations. Some popular websites include:.

This figure represents the quality of platypus environment within the Yarra River catchment. Red represents bad condition and green represents good condition. © Healthy Waterways Strategy 2018-2028.

Sitting in my kayak, I see as the platypus moves itself forward through the water using its brief, webbed limbs. Watching a wild platypus forage is something that very few Australians experience, and its such a privilege. However, my joy is overshadowed by the understanding that platypus face an unpredictable future in this river if nothing is done to assist them.

Regretfully you wont have any platypuses swimming in your regional rivers if you live outside of Australia. But do not assume that this preservation issue is isolated. The story of the platypus and Melbournes broadening urbanisation is a microcosm of what is occurring all around the world.

Platypus are under hazard from habitat loss. © Josh Griffiths.

In natural environments, rainwater soaks into the soil and is soaked up by the plant life, charging the groundwater and gradually releasing it back into our waterways. In metropolitan environments, our structures, houses, and roads replace forests and wetlands. These invulnerable surface areas gather, direct, and discard big volumes of water directly into our rivers and creeks, creating large flash flood occasions. Even light rain can massively increase the frequency and magnitude of these stormwater flood events, producing unnatural flow regimes that significantly impact freshwater ecosystems.

These floods are exceptionally troublesome for platypus. To find their food, platypus use fine-tuned receptors in their costs to map their environments by spotting electrical impulses in the water which are created by the muscle contractions of their victim, macroinvertebrates.

Without native riparian plant life, river banks end up being degraded and weak, which hinders a platypuss ability to create burrows and raise young. To fight this erosion, we set up city options such as concrete slabs and rock boulders, which just make things even worse. That very same study discovered that 48% of the Yarra catchments waterways are considered very bad environment conditions for platypus.

Why Riparian Vegetation Matters for Platypus.

Platypuses are also highly susceptible to litter and rubbish in our waterways as it can easily get caught around their costs. In Melbourne, platypus are up to 8 times more most likely to become tangled in litter than those in regional Victoria.

My pleasure is eclipsed by the knowledge that platypus face an unpredictable future in this river if nothing is done to assist them.

In spite of their status as an iconic Australian animal, platypus populations are dealing with extreme obstacles which threatens their survival. Platypus numbers have drastically declined since European settlement across Australia and are progressively decreasing in the Yarra River catchment.

The noises of birds and wildlife are replaced by the disruptive noise of industry. Trucks and cars fly over me as I paddle through an underpass, and the sounds of construction vibrates the air. Concrete lays where trees stood, and what was once wild is now governed by male. Similar to the loss of riparian vegetation, these impervious surfaces are likewise an issue for platypus.

Regretfully, this is already a reality. In the 1950s, Melbourne locals might discover platypus within 5 kilometers of the city centre. Today, you d need to travel more than 15 kilometers to have a chance at finding one.

This type of clearing is typical in peri-urban environments. In less than 200 years because European settlement, Victoria has destroyed majority of its native plants. A 2018 study discovered that the quality of greenery in the Yarra River catchment is improperly conditioned closer to metropolitan areas, which this decrease is spreading outwards from the city and into local areas..

It also provides a fantastic environment for platypus, who dig their burrows into these really banks. They give birth and raise their young, likewise known as puggles, for up to four months in these temperature-controlled burrows and need overhanging vegetation as protection.

Seeing the waters surface area, I suddenly begin to see a string of bubbles appear. Plop, plop, plop … and after that absolutely nothing. My kayak moves more detailed, my eyes lock, my thoughts quiet and breathing slows. A fluffy figure with a big, long beak and broad, flat tail pops to the surface area. A platypus!

Stormwater And Starvation.