Here are a couple of posts I designed for the Wilderness Society Victoria facebook page to celebrate International Day of Forests (today!). This is a critical time for our environment, and today is about celebrating our remaining wildplaces, reminding each other of the value in these ecosystems and pledging to stand together to protect them. For information about the Wilderness Society campaigns and ways you can get involved, check out our website.
installation by Issac Cordal
I have always depended on the kindness of strangers.
I wrote the following species profile as part of my Marine Megafauna course, and got top marks through peer review! Thought I’d share it here for anyone interested in knowing more about dugongs.
Top photo © Jürgen Freund, Indo-Pacific Ocean
Dugong (Dugong dugon)
- Dugongs are often referred to as “sea cows”, as they graze on underwater meadows of seagrass. They are the only marine herbivorous mammal, as all species of manatee rely on freshwater to some extent
- Dugongs can spend up to six minutes underwater before needing to surface to draw breath
- There is a theory that the tales of sea sirens or mermaids originated from sightings of dugongs by seafarers
The dugong (Dugong dugon) is a marine mammal in the order Sirenia. The family Dugongidae consists of only four species still alive today. The word “dugong” translates as “lady of the sea” in both the Tagalog and Malay dialect, from which the term was originally derived. Dugongs are also referred to as Sea Cows, Sea Pigs and Sea Camels, but are not related to any of these animals. Dugongs are most closely related to the Stellar’s Sea Cow, which, in the 18th century, was hunted to extinction by humans. Their closest living relative is the manatee, which they resemble, with the key difference being the shape of their tails. While the tail of a manatee is round and spade-like, dugongs have tails that are fluked. Both species are actually related to a giant land animal – the elephant – although the behaviour and appearance of elephants and dugongs has diverged dramatically.
Dugongs range in length from 2.4 to 3.5 m, with a weight spanning the 231 – 499 kg range. Their coloration varies; juveniles are a pale cream colour that darkens with age both laterally and dorsally, and adults can be anywhere from a brownish to a dark grey hue. Other factors that affect the colour of the skin include the growth of algae, which can give off a greenish tinge. These large herbivores can be found in warm coastal waters from East Africa to Australia, and span the Red Sea, Indian and Pacific oceans. The preferred habitat of the dugong is shallow tropical and subtropical coastal and island waters. There are estimated to be around 85,000 dugongs in the world, with the largest population found in the waters of northern Australia, from Shark Bay (Western Australia) to Moreton Bay (Queensland).
In the wild, dugongs can live up to 70 years, but have a slow rate of reproduction. Sexual maturity in dugongs does not occur until after 10 years of age, and can take some females until they are 17 years old. One calf is produced after a gestation that lasts around 13-14 months, whereupon the mother will assist the newborn with reaching the surface to take its first breath.
Photo by Rutger Geerling on Flickr
Dugongs are vegetarians whose entire diet is made up of different species of seagrass. Studies have shown that dugongs prefer grasses that are delicate and higher in nitrogen, such as seawrack (Halophila ovalis) and narrowleaf seagrass (Halodule uninervis). They forage throughout the day and night, uprooting whole plants using their snouts. Because of this behaviour, dugongs create distinctive trails where they have fed. They have also been shown to manipulate the seagrass beds when feeding to facilitate plant growth, a behaviour called “cultivation grazing.”
Dugongs have been long sought after for their flesh, oil, bones, skin and teeth. As they are languid and slow-moving animals, and congregate in coastal regions and around islands, they make easy targets for hunters. Due to loss and degradation of habitat, impacts of fishing, hunting and coastal pollution, the total number of dugongs seems to be in decline, with the populations becoming increasingly fragmented. To counteract this trend, dugongs have become legally protected throughout their range, with further conservation efforts being centred on protecting dugong habitat through the creation of Marine Parks. Currently, the conservation status of dugongs is listed variously as endangered, threatened, and vulnerable to extinction.
Photo by Andrew Rankin
Dugong Expert: Professor Helene Marsh
Professor Helene Marsh’s research has centred around the population ecology and management of dugongs. Her research has formed the scientific basis for major marine conservation efforts, such as the establishment of Dugong Sanctuary in the Torres Strait. Helene is the current Dean of Graduate Research Studies and Professor of Environmental Science at James Cook University, and a program leader in the Marine and Tropical Science Research Facility.
Department of the Environment (July 2013) Dugong dugon in Species Profile and Threats Database, Department of the Environment, Canberra. Available here
Kelly N, Peel D (November 2013) Unmanned Aerial Vehicles (UAVs) for Surveying Marine Fauna: A Dugong Case Study. Available here
D’Souza E, Patankar V, Arthur R, Alcoverro T, & Kelkar N (October 2013) Long-Term Occupancy Trends in a Data-Poor Dugong Population in the Andaman and Nicobar Archipelago. Available here
Yep, that's me - looking as attractive as ever in a pair of waders, smelling like 'pond'...
While my one-day Earthwatch expedition was certainly dirty work and more than a little tiring, I had a great time learning from scientist Lee and actively participating in her research with fellow volunteers Emma and Gabriella. Our mission: to gather data on turtle habitat and turtle populations in the greater Melbourne region!
It was an early start, compounded by the fact that we’re still in daylight saving mode here in Melbourne, which meant waking up in total darkness, waiting at the bus stop in total darkness, travelling in total darkness (I am aware that some people do this every day) and waiting at the rendezvous point in – you guessed it – no you didn’t – semi-darkness.
First to arrive! Showing my supreme eagerness to get the day underway.
After a quick PowerPoint to bring us up to speed on the project, the vollies split into two groups of three and jumped into a car with one of the scientists. Each team had two sites to monitor; ours were in Mill Park. We spent the day in waders: setting up eight turtle traps, collecting and anlaysing dip-netting samples, assessing the quality of the water and checking and removing the traps.
My team hard at work While my team is hard at work analysing and documenting water samples in the background, here I am conducting my own analysis/documentation...
Unfortunately for us, we didn’t catch any turtles – unsurprising perhaps because this is the last day in the season (Earthwatch will run sessions again starting in January). However, the team stationed in Doncaster managed to nab three, which would have each been measured, weighed and tagged. We didn’t come up entirely empty-handed though…have a look at what we found in one of our cathedral nets:
All in all, it was a great day outdoors 🙂
Drafted the below media release earlier this week on behalf of the Wilderness Society Victoria. Unfortunately, the court ruled in favour of DEPI, so it seems the days of the Little Red Toolangi Treehouse are numbered. We can only pray that the same is not true for the Leadbeater’s possum.
Treehouse occupants stand (29.6m) tall against government takedown
By Meg Bauer
March 12, 2014
Mansfield, VIC: Young conservationists have been taken to court today over a treehouse constructed to protest the proposed logging of Mountain Ash trees in the Toolangi State Forest. The Department of Environment and Primary Industry (DEPI), the governing force in state forests, put a summons on the nearly 30 metre tall tree around two and a half weeks ago, calling for the owner of the treehouse to come forward or the matter would go to court. The hearing will take place at Mansfield Magistrates Court at 10 AM.
As a show of solidarity, fellow forest defenders including the Knitting Nannas of Toolangi (KNOT), Mansfield locals and members of the Wilderness Society Victoria will be staging a demonstration outside the courthouse to gather community support for the cause and further protest the proposed logging venture.
Non-Violent Direct Action has been taking place in the Toolangi State Forest for over a decade, with this latest tree-sit campaign ongoing since November last year. Beee, the previous occupant of the treehouse, recently came down to ground after 86 days straight and was promptly replaced by Harley.
Upon his ascension into the canopy, Harley declared, “I am 110% committed to putting everything I can into this campaign to save our beautiful forests and all the creatures that call these places home.”
Beee, Harley and members of the support camp at the base of the tree say they aim to educate and empower the public to respond to the commercial destruction of Australia’s native forests.
The Little Red Toolangi Treehouse, as it is known, is carefully positioned in an area of the forest where the world’s largest flowering tree, the Mountain Ash, is found. This is the habitat of Victoria’s state emblem, the fragile and threatened Leadbeater’s possum, which needs old growth like the Mountain Ash to nest in.
Harley explains, “This is why it is so important to keep the fight going to save our forests. These massive old trees provide a home to the endangered Leadbeater’s possum, the sooty owl and many other creatures. Studies also show that the Mountain Ash forests of Victoria and Tasmania are some of the most carbon-dense forests on Earth…(It’s clear that) logging in our state forests needs to stop.”
Emblazoned in fire-engine red and suspended at an imposing height, the treehouse is effectively standing sentinel over the forest, at the same time raising awareness of the cause.
If the case goes in favour of DEPI they will claim ownership of the treehouse, and inevitably remove it.
To learn more, please visit:
Little Red Toolangi Treehouse Facebook Page
*All images borrowed from the Little Red Toolangi Treehouse facebook page