Delta Downs Expedition (Part Two) by Liz Xanthopoulos

Delta Downs Expedition (Part Two) by Liz Xanthopoulos

by Liz Xanthopolous, A visitor to this time


Home became the banks of the river, which had a 3 metre steep elevation from the water, so we were completely safe from said Jurassic creatures creeping up and snatching one of us while we slept. We found a large patch of dirt to set up camp next to a little pond, surrounded by long green grass, tall brown termite mounds as far as the eye could see, and some trees and bushes. To add to the ambiance were dried up piles of cow poop all over the place that we shoveled out of the way. Our new little home was known as Snake Creek, which lived up to its name when Barbara nearly stepped on a Brown Snake one night while checking the tide, and after we came across a few more around camp I was very quickly forced to overcome my fear of snakes. The scenery around us was vast, open and never-ending. It was nature in all its glory. Wild and beautiful, and so silent. Every sunrise and every sunset we were treated to the most beautiful shades of pink and orange in our sky, and every night the brightest stars I’ve ever seen would come out and put on a show.

         Our tagging shifts were twice a day, in three person teams. The morning shift, my shift, usually started at about 5 am, until about 11 am. It was still dark when we’d get out on the water, so we had to use our headlamps and the boat’s spotlight to get our work done. Crocs are most active at night, it’s their favourite time to hunt so they’re out and about. We made sure we used the boats spotlight to scan the banks of the river, for navigating of course but also to make sure we were constantly monitoring our surroundings. Their eyes reflect light so we would often see tiny little red eyes looking at us in the dark. To be honest, even though croc safety was emphasised and mentioned in all the paperwork, I had no idea how big a factor they would actually be, but after arriving at Snake Creek, talking to the rangers and taking into account of course Barbara’s previous experiences in these areas, I knew we would have to take procedure seriously and stay focused to make sure everyone on board was as safe as possible at all times.

We would begin our sessions by setting up four drum lines and two gill nets, and routinely checked and moved them to different spots along the river to better our chances of catching something. It did get easier to work after the sun came up and we had more light, and it was still early enough so the heat wasn’t as scorching as it would be later in the day, but nevertheless the shifts were still physically demanding. Lifting and throwing anchors, reeling in and then releasing the nets, pulling out and releasing any bycatch over and over and over again, all the while making sure we weren’t hanging over the side of the boat or sticking our hands in the water to avoid tempting the crocs stalking us from beneath the surface. I think even Barbara was surprised at the huge number of jellyfish that were in the river system. Pulling up these 50-metre-long nets that essentially became a wall of jellyfish because there were so many were drifting into the nets became really challenging. I’ve been stung by jellyfish a couple times before while up on the Gold Coast, so their sting wasn’t anything new to me, but it just meant that we had one more thing that we had to be cautious of.

After getting back to camp once our sessions were over, I would usually run straight to our kitchen and shovel down as much food in me as I could to replenish all the energy we’d lost in the morning. I also had a couple of Hydralyte’s a day to make sure I was properly hydrated. After breakfast/lunch we would wash as much mud/sunscreen/fish guts (from the bait) and sweat off us as we could – using nothing more than a quarter bucket of water and a washcloth (hey, it did the job!), change our clothes, and try to stay in the shade to conserve our energy. Walking from our “shower tent” to my swag was an adventure of its own if I dared make the trip barefoot. The path to get to there forced me to walk past the biggest termite mound, and if the ants around there were quick enough to jump on my feet as I crossed through I was in for a hell of a sting.

We would spend the rest of the day listening to music, or the ‘Serial’ podcast one of the marine biologists brought and then discuss it, we’d talk about life or different birds that we’d spot, and collect wood for our fire. After getting dinner ready, having a chat around campfire while eating, and washing up, the evening shift would head out just before sunset for their session, and usually wouldn’t make it back until after midnight. Those of us on the morning shift would try to get to bed early and get a good night’s sleep to be fresh for the morning after. Oh yeah! I forgot to mention – late in the evening it was crucial to put on long sleeves and spray heaps of insect repellent on. I’m not a person that ever gets bit by mosquitoes, but out there, I got mauled. Mozzies and midges everywhere. You could never escape it, and it was bloody frustrating as hell.

I’ll never forget the ray we caught on one of our drum lines. While I was pulling the line up I could feel it getting heavy and I knew we had something, and suddenly a long black slimy tail broke the surface of the water. The first thing I thought was (don’t laugh at me) “oh my god, it’s a snake!” but once I saw the rest of its body I realised it was actually a big ray. We kept the line in its mouth and towed it to the little bank in front of our camp because it was too big and too heavy to lift onto the boat like we normally would’ve. There we checked the gender (it’s a boy!), measured him, took some photos and tagged him. His body was about 1.5 metres wide, so he was a big boy. I had to put my hands in his gills to lift him up so Barbara could get the hook out of his mouth, so I ended up with essentially ray snot on my gloves. I even found myself patting him like a dog, I guess I thought that if he felt my hand he might feel comfort, and he’d know that he’d be OK, because I can only imagine how scared he was. Barbara later identified him as a Freshwater Whip Ray. We caught another one a few days later but he was much smaller.

Despite all our hard work, planning, and best efforts, it wasn’t in our fate to encounter the incredible sawfish. All the data we collected will still contribute to SARA’s research, maybe not in the way we hoped but I’m sure we collected more pieces to the puzzle. I remember Barbara telling me that most people become completely captivated by sawfish when they first set their eyes on them because of their strange appearance, and although I missed out on that moment, I did not feel disappointed with my experiences during the expedition. Having the privilege of witnessing the beauty of one of the most untouched locations in the country that only a handful of people have visited, and having the opportunity to participate in an important scientific research expedition with a great group of people far exceeded any expectations I had. And so, after the most amazing 10 days at Snake Creek, it was time to pack up camp and start the two-day trek back to Cairns. We made it all the way to Croydon when we decided to stop for the night at a caravan park and treat ourselves to dinner and a couple of drinks at the local pub. We all walked in and stopped in our tracks when something caught our eye on the wall behind the bar. Two sawfish rostra. Two sawfish rostra hanging on the wall in a pub. Yeah, heartbreaking. But it did bring us back to reality and confirmed to us that everything we just went through won’t be for nothing. There’s still a lot of hard work that needs to be done and the biggest challenge will be changing people’s perceptions and attitudes toward animals, but it can and will be done.

Just like that, after all that time in the middle of nowhere, with no communication with the rest of the world and only the six of us for company, just us vs the wild, we were back in Cairns. It just seemed so loud to me. So loud and so busy, and it took me a couple of days to get used to being surrounded by so many people. I spent a few more days in Cairns exploring, drove down to Mission Beach and Etty Bay to find some Cassowaries, and went over to my beloved Great Barrier Reef for a few dives (I will talk about my love for the Reef in many posts to come), and then it was time to head home. Actual home. Melbourne home. The same night I arrived I was sitting on the couch watching TV when my mum asked me how it felt being home. It felt strange. I caught myself looking over my shoulder and looking around me to make sure nothing was trying to sting me or bite me. It felt strange feeling safe. The Delta Downs expedition was my first real call of the wild, and I’ll hold onto the experiences I had there forever. Without a doubt, there will always be a part of me that’s constantly seeking it out. Even when walking my dog, certain smells or sensations make me feel like if I close my eyes I’m back in Snake Creek sitting around the campfire having a laugh over dinner watching the sun set. Whenever life starts getting a little overwhelming and I get that urge to run away, my mind drifts back to the simpler times of Snake Creek where the only thing I really had to worry about was eating and not being eaten! Just the way nature intended.


Delta Downs Expedition 2016 (Part One) by Liz Xanthopoulos

Delta Downs Expedition 2016 (Part One) by Liz Xanthopoulos

by Liz Xanthopoulos, A visitor to this time 


“Don’t think about, just go!” was the last thing Hannah said to me before I took a deep breath and flung myself over the side of the boat landing in shin deep, crocodile infested waters. What happened next is kind of a blur. I ran as fast as I could to get to our anchor which was now buried about half a metre deep in mud on the river bank and all I could hear was Hannah’s voice shouting at me “it’s ok, there’s nothing there, just grab the anchor and run back!”. I was watching the long grass a few metres away from me to make sure there was nothing lurking in there waiting for the perfect moment to run out and maul me, when I finally got the anchor free and bolted back to the boat, anchor in hand. I jumped back onto the boat and started shaking with adrenaline! 


Even though we finally got our anchor free and back on the boat, we were still heavily stuck in the mud. After an hour of trying everything we could to get out, there was only one solution. Get back in that bloody water and push. We had already been revving our engine for a while so once we rechecked the depth of the water around the boat and made sure we had a clear coastline, Barbara – our expedition leader, and I hopped back in the water and pushed our boat as far away from the bank and out of the mud as possible. If you don’t know the “urban rule” about crocs, it goes something like this: For every croc you can see, there are about 10 under the water that you can’t see. I call it an “urban rule” because the number seems to change from region to region. In Darwin they say 10 crocs, in Queensland they say 20. Either way, out here, in the middle of nowhere, I wasn’t in any way willing to test the rule.

This act of stupid bravery, however, did earn me the nickname “Jesus” back at camp, since I ran through the water so fast it was like I ran on the water. And being among a group of biologists on a scientific tagging expedition when you’re just a business school drop-out…well let’s just say it gave me some “street cred”. The reality of the situation was that if we hadn’t gotten our boat free when we did, we would have had a veeeeery loooong day and night ahead of us, waiting for the pretty unpredictable tide to flood back in and free us. And this was only session one, of a ten-day expedition!

We started the two-day drive to Normanton, Queensland on the 19th of June, last year, starting from Cairns, where Sharks and Rays Australia (SARA) is based. SARA was founded by Dr Barbara Wueringer, to “conduct scientific research to contribute to conservation efforts of endangered species”. Barbara has spent the last 12 years of her career capturing, tagging, and releasing lemon sharks, tiger sharks, and her favourite – sawfish, all over the world. She has had her research featured in publications including National Geographic, New York Times, Science Magazine, and Discovery Magazine. In 2015 SARA started measuring the “current distributions and abundance patterns of four species of sawfishes in Far North Queensland and the Cape York Peninsula”.

Sawfish are a family of Rays, and have a characteristic long, flat, and narrow rostrum, lined with sharp teeth in a way that resembles a saw. They’re a pretty fascinating animal! Their rostra are covered with electrosensitive pores that they use to detect even the slightest movements of prey hiding in the muddy sea floors. They also use their rostra as a digging tool, and to slash prey as it swims by. If you haven’t already, make sure you YouTube a video of it – it’s amazing. Unfortunately, it’s because of their incredibly distinctive feature that they are now listed as critically endangered and at risk of extinction.

It’s estimated that their population numbers are at less than 5% (to maybe as low as 1%) of their historic levels. Not only are they caught as bycatch in fishing nets because their rostra are easily entangled, they are also exploited for it, with fishermen butchering it off as a prize or to sell in some markets. Their fins are also taken to supply the distorted, delusional, and dangerous Asian market. Northern Australia is the last global stronghold for the four species of sawfish, as stated in on the SARA website. It’s believed that the coastline and river systems of the Cape York Peninsula most likely hold the highest densities of sawfish. In Queensland waters, sawfish have been declared a no-take species, but since the last assessment of their numbers ended in 2008, it’s unclear if the ban has had an effect on population numbers. And so… here we are.

Our small team consisted of three marine biologists including Barbara, an animal scientist, our hilarious camp supervisor Andrew – who was essentially our very own Bear Grylls, and me – with my passion for marine conservation and my superhuman ability to run on water when I’m scared of being eaten alive by Jurassic creatures. Since my marine biology degree is non-existent, I have to do the best I can with what I’ve got.

We set up camp for most of the duration of the expedition at a place called Delta Downs, which is an Aboriginal-owned cattle station about 70km outside of Normanton. Normanton itself is a very small cattle town in the Shire of Carpentaria, with a population of about 1,400. Getting to Delta Downs literally means 4×4 driving down a dirt track for most of that 70km, but you understand why when you realise that its one million acres makes it one of the largest Aboriginal-owned cattle properties in Australia. Delta Downs is also known as Morr Morr, and is operated by the Kurtijar People. Up until recently, Delta Downs completely forbid entry to the public, but in going back and researching for this post, I’ve seen that they now have a website where you can apply for permits to camp there. For our expedition, we had to get permission from the traditional owners to stay and conduct our research, which wasn’t a big issue since Barbara had put in the work to build a good relationship with them before we even got there. So, once we had their final ok, we went off to set up our camp on the Gilbert River, only a few kilometres away from the Gulf of Carpentaria, and got ready to do some work…

2016 in review

2016 in review

I am sitting in my office in Cairns. When I look out of the window I can see dark clouds hanging in the sky, bringing with them the beginning of the wet season. As our remote field sites can only be accessed by dirt road, these clouds indicate the end of our field season 2016. But what an amazing year it has been!

In 2016, Sharks And Rays Australia commenced expeditions with volunteer field assistants. The response to our call for field assistants at the beginning of the year was fantastic, especially for the fact that this was our first year. People from all over Australia joined us in the field, many of whom were biologists.

We have also been joined by Indigenous Rangers in the field. SARA is now collaborating with five Indigenous Ranger Groups, and their help in the field is invaluable. These guys know their country like the back of their hand, and helped us overcome the many logistical challenges such as launching the boat in areas where there are no boat ramps. They also know which areas are inhabited by particularly large crocodiles and showed us how to read the depth of the river based on the surrounding terrestrial vegetation. Their interest in sawfishes and our research was also incredible, which is very encouraging. For example, the Kowanyama Land and Sea Rangers joined us in the field and on the boat, and almost every one of the Gangalidda-Garawa Land and Sea Rangers joined our presentation and induction. These collaborations make our work more fun and exciting but they are also important. After all, the majority of Queensland’s rivers in which sawfish are likely still abundant, are bordered by country that is under Native Title claim.

Together, we have discovered many amazing places in the Queensland tropics that are completely off the beaten track. We have commenced our study in seven rivers that all flow into the Gulf of Carpentaria, from near the Northern Territory border in the west to north of Weipa. We have experienced an abundance of wildlife, from swarms of grasshoppers, to snakes crossing rivers, to iconic Australian species such as goannas, kangaroos and emus. Our fieldwork was often done under the watchful eyes of saltwater crocodiles and wedge-tail or white-bellied sea eagles. We rescued blue-tongue skinks and pythons that were sunbaking on the roads, and stood in awe of corypha palms that were in bloom. How I miss sitting by the campfire and listening to the songs of whistling kites.

The landscapes we have worked in have been truly stunning and unique. From the endless salt marshes of the Nicholson River to the grasslands that surround the Mitchell River. But we have also seen at first hand the large-scale mangrove die-offs that nobody talks about. It is yet to be seen what these die-offs mean for so many fish and also sawfish that use these submerged forests as nursery grounds.

We also caught, tagged and released 49 elasmobranchs, belonging to seven different species. The most commonly caught sharks were juvenile bull sharks Carcharhinus leucas, with 25 individuals, followed by freshwater whip rays Urogymnus dalyensis, with 6 specimens. Sampling in coastal regions did not get us any of the elusive Queensland sawfish Pristis clavata or Green sawfish Pristis zijsron but we caught, tagged and released five freshwater sawfish Pristis pristis. The diversity of elasmobranch body shapes was reflected in our samples, with juvenile giant shovelnose rays Glaucostegus typus as well as juvenile eagle rays Aetobatus ocellatus being caught. But we have also found evidence of sawfish being finned – a practise that is illegal for anyone in Australia.

As we are not only aiming to understand our study species but also gain a better understanding of the ecosystems they occur in, we also analyse our by-catch, almost all of which was released alive. A total of 276 fish were identified, measured and released! By-catch was clearly dominated by fork-tailed catfish, and within that group Sciades paucus the shovelnose catfish took the lead. These results clearly show that gill nets and drum lines are only selective by size and not by species, but our sampling strategies have also proven to be effective in ensuring that most animals are released alive.

Our field assistants have brought many skills to our expeditions this year, and they have also learned many things, about our research, sawfish, our methods and also about themselves! Spending time in relatively untouched, remote ecosystems often brings us back to ourselves and exposes our strengths and fears. But as a team we can overcome these challenges and learn from each other.

In 2017 SARA will expand even more. We will continue to run our project on the assessment and distributions of sawfish and other sharks and rays in our study area. With this we will continue to collect DNA and stable isotope samples, and we are hoping to explore more rivers.

We will help Mangrove Watch assess the state of the mangrove forests that we work in, and we will commence sampling rivers for environmental DNA (eDNA) of sawfish, in collaboration with Prof. Colin Simpfendorfer from James Cook University.

We also hope to increase our presence in local schools, not only showing kids what we do but also introducing our food web game that will be developed in collaboration with Sharks4Kids.

We are hoping to commence trials for new methods of capturing sawfish. And hopefully SARA can grow, as we will be seeking students to take over some of our projects, like the stable isotope study of river food webs, and our accelerometer study of sawfish behaviours. So stay tuned, join our newsletter and regularly check into our facebook page!

Click here to see 2016 in pictures

The saw-less sawfish?

The saw-less sawfish?

Access the original blog post written by Barbara for the Save Our Seas Foundation here.

The first time I saw a sawfish, I was mesmerised. The question that sprang instantly to mind – and also the one that I get asked the most – is, what is the saw used for? To say that I found this question fascinating is an understatement, as I spent four years of my life trying to answer it. My PhD project, which I finished in 2011, focused on the feeding behaviour and sensory biology of sawfishes. And I can tell you already, the deeper I got into the topic, the more fascinating it became.

The saw is an elongation of the rostral cartilage. The elongated rostrum, which also bears lateral teeth, evolved at least three times independently in elasmobranchs: twice in rays and once in sharks – in the family Sclerorhynchidae (extinct sawfish), the family Pristiophoridae (sawsharks) and the family Pristidae (living sawfish). For my research I compared sawfishes with their close relatives the shovelnose rays of the family Rhinobatidae. As both taxa are likely to have evolved from a common ancestor that was similar to shovelnose rays, the comparison enabled me to provide a hypothesis about the evolutionary benefit of the saw in living sawfishes.

My research found that the freshwater sawfish Pristis pristis uses its saw both to sense prey (via electroreception and touching) and to manipulate it. Interestingly, juvenile freshwater sawfishes slash at an electric dipole, which resembles visually hidden prey, only when it is suspended in the water. Shovelnose rays hardly react to these fields. When a sawfish encounters an electric dipole field on the bottom, just like a shovelnose ray it tries to gobble up the field source with its mouth. These results clearly indicate that the evolution of the saw enabled sawfishes to expand their hunting strategy to include fast, free-swimming prey.

The saw, however, is also what gets sawfishes into trouble. Saws easily get entangled in fishing gear and the sawfishes wrap themselves up even more in nets when they try to escape from the invisible danger, sometimes becoming dangerous to handle. Saws are also sought-after trophies. Even though all species of sawfish are listed on CITES and the four species in Australia are protected locally under federal and state legislation, saws can still sometimes be found for sale at local markets or on e-bay.



I had always thought that fishermen were taking whole sawfishes and selling the fins separately from the saws. After all, sawfish fins are among the most valuable in the international shark-fin trade and can fetch a few thousand dollars each. But there is a different, even more disturbing practice. Fishermen, both commercial and recreational, are cutting off a captured sawfish’s saw before releasing the animal alive. Although I had heard rumours about this practice, it was only in November 2015, when we finally ran the first research expedition with Sharks And Rays Australia to the Norman River, that I started to realise just how much of an issue it could be.

Situated in the south-eastern corner of the Gulf of Carpentaria, the Norman River is a Mecca for commercial and recreational fishermen who are after barramundi. It is fairly accessible, being one of the few destinations in the Cape York region that can be reached by a paved road. Moreover, public concrete ramps enable boats to be launched easily at Normanton, which lies inland on the river, and at the coastal fishing port of Karumba.


bw-img_2339-sm During the closed season for barramundi fishing, the boats parked in the Karumba gardens overshadow the houses. Photo © Barbara Wueringer | Sharks And Rays Australia.


Setting, checking and retrieving gill nets in this river was an adventure. We were manoeuvring in waters with an average visibility of 10 centimetres (four inches). Hidden under the surface were landscapes of boulders, sunken logs and sand bars that were only visible with the aid of modern technology. The presence of large saltwater crocodiles took the required alertness and protocols to the next level. We had prepared for encounters with all kinds of creatures, from our study species to sand flies, mosquitoes, stingrays and stingers. What made the sampling even more difficult was that the river was full of jellyfish. Our net setting required fine-tuning.

After four days of sampling we managed to capture, tag and release one juvenile bull shark and one sawfish. I don’t think that this low sample number reflects the sawfish population of the Norman River, but it will take many more field trips to find out. As a result of our outreach efforts while we were at the Normanton Tourist Park, we received reports of two accidental sawfish captures that took place just days before we arrived. When the sawfishes were captured by recreational fishermen, the saws of both were already missing. The fishes were released alive, but their chances of survival are slim.


Can you see the crocodile's foot prints? The entrance to a hide out of a saltwater crocodile Crocodylus porosus. The belly slide is around 50 cm wide, indicating a large animal. The entrance to a nesting site of a saltwater crocodile Crocodylus porosus. The belly slide is around 50 cm wide, indicating a large animal. Photo © David Nash | Sharks And Rays Australia


A group of pelicans - which is called a pod - in the southern Gulf of Carpenteria A group of pelicans is called a pod! Photo © David Nash | Sharks And Rays Australia.


Together with the Save Our Seas Foundation Media Unit, the material submitted was turned into an educational video so that this sad occurrence could be turned into an opportunity for public education. Please share it widely.




  • In countries where sawfishes are protected, the removal of a sawfish’s saw is illegal.
  • As sawfishes are listed by CITES (the Convention on International Trade in Endangered Species), any international trade in sawfish body parts or live animals is regulated.
  • In Australia sawfish are protected under the EPBC Act.
  • When the saw of a live sawfish is removed, the brain cavity is opened, resulting in the sawfish’s slow, lingering death.
  • A sawfish uses its saw to find and manipulate its prey. It also uses it to defend itself.


Further reading
Morgan DL, Wueringer BE, Allen MG, Ebner BC, Whitty JM et al. 2016. What is the fate of amputee sawfish? Fisheries 41(2): 71–73.
Seitz JC, Poulakis GR. 2006. Anthropogenic effects on the smalltooth sawfish (Pristis pectinata) in the United States. Marine Pollution Bulletin 52: 1533–1540.
Wueringer BE, Squire LJ, Kajiura SM, Tibbetts IR, Hart NS et al. 2012. Electric field detection in sawfishes and shovelnose rays. PLOS ONE 7: e41605.
Wueringer BE, Squire LJ, Kajiura SM, Hart NS, Collin SP. 2012. The function of the sawfish’s saw. Current Biology 22: R150–R151.


The sawfish's gills are flushed with water during the work up. Teagan Marzullo and Barbara Wueringer tag the first juvenile freshwater sawfish, Pristis pristis, captured for this study. Photo © David Nash | Sharks And Rays Australia.


dn-img_2411-xs SARA’s field team posing in front of a croc statue in Normanton, Queensland © David Nash | Sharks And Rays Australia.


Sawfish art work by Sue Ryan

Sawfish art work by Sue Ryan

Last week we were fortunate to visit Sue Ryan in her studio near Tomoulin, Far North Queensland. Sue had just finished her sawfish figure. It measures 4.5m long and was comissioned by the Glasgow museum. The frame of the sawfish was made from a chicken wire and bamboo. Its surface is made from ghostnet material that was collected along the coast line of the Gulf of Carpenteria. Sue picks the fibres apart and sews them carefully on the frame. Another artist, Ricardo Idagi from Murray Island, designed the pattern on the dorsal side of the sawfish. The project took seven months to complete.

The week after we visited, the sawfish was placed in a box and is now on its way to Glasgow. I am sure it will be the star of the collection!

You can see more of Sue’s work in an art gallery in Sydney (