The cultural importance of sawfish in Australia

The cultural importance of sawfish in Australia

by | Aug 19, 2019 | Blog

Once a year, the Cairns Indigenous Art Fair kicks off in Cairns. Indigenous artists from all over Far North Queensland and Cape York come to Cairns to display their arts. The event grows bigger every year and features so many works on sharks and rays that we always try to be in Cairns for CIAF.

This year, Julia, who is our instagram wizard, and myself visited CIAF together. We grabbed some food and sat down in the grass to listen to what was going on at the stage. Various Indigenous leaders from the Cape were talking about how their language and culture was slowly being lost. At some point, one of the elders started to talk about sawfish. He said that they had disappeared from his native waters and that he was from the community of Pormpuraaw. I looked at Julia and said, ‘We need to talk to him!’

After the session we introduced ourselves to Syd Bruce Shortjoe. I told him that we work with sawfish and that we would like to help him protect these animals in the waters of Pormpuraaw. I told him that SARA already works with the Mapoon Land and Sea Rangers as well as the Kowanyama Land and Sea Rangers. As I had heard of recent captures of sawfish from the Pormpuraaw region, I said to him that sawfish still exist in his native waters, but probably in very low numbers. I also gave Syd one of our flyers and a sunnies neoprene strap that has all the information on how people can submit sawfish sightings to us. While Syd was listening, he started stroking the sawfish image on the neoprene strap.

Syd told us that his great grandfathers’ totem is the sawfish. He said that because of this, the sawfish is part of his family and his culture. If the animals go extinct, then not only is the species missing from local ecosystems, but it also means that the totem goes extinct. In his cultural belief, you become your totem animal after your death. His grandfather’s totem is the green sawfish, and Syd described the animals very accurately. In Mugu, the sawfish is called kapainyinh.

Syd is the first person who I have met who had a sawfish totem in his family.

He looked at me and grabbed my arm. He said ‘Sawfish cannot disappear. This means my family’s totem disappears and my culture disappears. And with your help we can stop that.’ I grabbed hold of his arm and said to him that I will help him and I will try my best to teach his community, his people, the school kids and the rangers so that we can all come together to look after sawfish and bring these animals back to his waters.

This moment was highly emotional for Julia and myself. While we often meet people who are very interested in sawfish, and while we both understood the cultural importance of sawfish to Indigenous Australians, we were completely unaware of the cultural impacts of the species’ declines.

When Syd looked at me and asked me for my help I realized that there is too much at stake. We need to look after sawfish and we need to do this together.

At the Cairns Indigenous Art Fair. From left to right Barbara Wueringer (SARA), Eliot Koonutta (Pormpuraaw artist), Julia Constance (SARA) and Syd Bruce Shortjoe (Pormpuraaw Elder)

This blog post was written for the Save Our Seas Foundation. Access the original here.

 

Sawfish or sawshark?

Sawfish or sawshark?

by | Feb 18, 2019 | Blog

By Paddy Burke (Sharks4Kids ambassador & PhD student at Macquarie University, @Patrick_Burke)

The ocean is filled with so many incredible creatures, incredible and bizarre. Many of these fish have evolved under similar pressures which have led them to look quite similar even if they are genetically quite distinct. This similarity in appearance or development of similar structures is what is known as homology. One great example for this can be seen in sawfish and sawsharks!

Now many of you may be saying, wait, aren’t those the same thing? The answer is no! While these two groups of fish are very similar in appearance, they actually have quite a few big differences that can make it easy to tell them apart once you know them! The differences we will cover today are their ‘saws’, general body size and the gills.

The ‘saws’ or elongated toothed rostra are the features that make these fish really quite unique. The saw is thought to be used for predation and defense in both groups. However, the actual structure of the saw is really quite different! Sawfish saws are lined with a number of teeth along both sides of their saw that vary in size and number by species but each one of these teeth are permanent! Meaning that if they happen to lose one it will never grow back. The rostral teeth of sawfish also grow from their base, like a rodent’s tooth, so that the animals can sharpen them regularly in the sand.  Sawsharks on the other hand have a very different saw. Teeth can be found along both sides of the saw like in sawfish, however, sawshark teeth are replaceable! The most distinguishable feature to separate a sawfish and a sawshark saw is the presence of what are called ‘barbels’. Barbels are found only on sawshark saws and they look like a little moustache coming off the saw. This moustache is thought to have a tactile function, meaning they use them to feel around in the sand for food.

The size of fish is an easy indicator of species between these groups. Sawfish are very large fish, some reaching over 7 meters in length! While sawsharks are much smaller, averaging around 1 meter for an adult depending on species. In addition to size, it is important to know that sawfish are technically rays while sawsharks are true sharks. What that means is that in sawfish you will find their gills located on the underside of the fish. Where as in sharks they are located on the side of the head. 

These fish could be considered ‘cousins’ in a way since they are both chondrichthyans, meaning they both have a skeleton made out of cartilage instead of bone. However, it is important to remember that sawfish are actually rays while sawsharks are true sharks. Sawfish may not follow the typical body plan of their relatives the stingrays, but they are more closely related to them than they are to sawsharks!

A sawshark, Pristiophorus nudipinnis resting on the substrate. See the barbels? Image by Tristan Guttridge. 

A freshwater sawfish, Pristis pristis, is disentangled from a gill net in order to be tagged and released. Its teeth are evenly sized and spaced, contrary to those of sawsharks. Image by Dave Nash.

Accelerometer tags on a sawfishes’ saw

Accelerometer tags on a sawfishes’ saw

by | Dec 15, 2018 | Blog

 

We were out in the waters of the Mitchell River, near the Indigenous community of Kowanyama. Every day we would wake at 3am ready for a 4am start of setting nets on the river. After a 7hr sampling session, we’d eat and rest and then run another sampling session in the evening, either hand-lining for freshwater whiprays (last year we had also caught a saw-less sawfish like this), or setting more nets.

The first few days we were only catching small bull sharks, which is fairly stressful when gill netting. Sharks don’t do well in gill nets, but in this part of the river, which is freshwater, many of the sharks we had caught over the last three years had a fungus infection visible on their skin. This meant that we had to be even faster releasing them, otherwise they would struggle.

One morning, we had caught multiple juvenile bull sharks in one net, so many in fact that we were continuously checking the net to get them all out so that we could pull the net without injuring them. When the net was finally retrieved, and we arrived back at the camp, we were greeted by a very angry couple waving paperwork at us (in the middle of nowhere) shouting that they had booked this particular camping spot where we had set up our camp. As we did not want to get in trouble with anyone, and our booking had been made by the local rangers who were on weekend break, we had to move. The move took about 3 hrs, and our new camping spot, the only one providing a safe entrance to our boat, also displayed a stark reminder of the presence of saltwater crocodiles (Figure 1).

Fig. 1: Upon assessment of our second camping spot we found this footprint of a saltwater crocodile Crocodylus porosus. Saltwater crocs can be quite dangerous to humans and a colleague from Australia Zoo estimated the owner of this footprint to be over 5m long. Barbara’s foot is a size 38 European. However, during our time at the camp spot this crocodile would have not been able to lift itself up the steep riverbank because of low tides.

After an afternoon nap, everything changed. We all agreed that our new camping spot was better than the old one, and started over. We became friends with our neighbours. There were no more bull sharks in the net, but sawfish! And we were finally able to deploy our custom-built tags. These tags combine an accelerometer, which records the movement of the rostrum in 3D space, with temperature, light and pressure sensors, in a casing that allows the tags to be mounted on the base of a sawfishes’ rostrum. An acoustic tag allows active tracking of the animal and a VHF tag allows us to find the tag once it has detached.

There are many release mechanism for tags in saltwater and they generally involve corrosion. In freshwater this does not work and so we tested our own ideas of dissolvable string. With the ‘perfect’ lab-tested configuration, the first tag detached upon release of the animal (2 mins into a 3 day deployment). We modified the set up, and the second and third tag released after about 4 hrs. The fourth tag finally stayed on (figures 2,3 and 4).

Fig 2: Sarah O’Hea Miller helps Dr Wueringer to attach the first accelerometer tag to the saw of a juvenile freshwater sawfish Pristis pristis.

Fig 4: A happy SARA team is ready to release this freshwater sawfish, Pristis pristis, with its tag attached.

With a team of four, and three people required on the boat for tracking, it was difficult to take turns going on land, relaxing and preparing food. After close to 30 hrs of tracking the sawfish, with only 3 hrs of sleep, we recovered the tag. Having worked with sawfish for 13 years, this included one of my most memorable moments of fieldwork. As the tag had not been moving for a while, we decided to head to the side of the river where it was located. In order to not scare the sawfish, I beached the boat further upstream, got out and moved to the high bank under which the tag was pinging. The water was clear and I could see the little sawfish with our tag attached to its rostrum hunting baitfish.

One of our field assistants was so impressed by what she had experienced on the expedition that she even ended up with a tattoo of a sawfish (figure 5). Clearly these animals are not only of cultural importance to Indigenous Australians, but to all of us.

 

Fig 5: One of our volunteer field assistants turned her experiences of the expedition into a permanent memory in the shape of a sawfish tattoo.

This blog post was written by Barbara for the Save Our Seas Foundation. You can access the original here. 

Queensland and it’s sawfishes. by Nicolas Lubitz & Barbara Wueringer

Queensland and it’s sawfishes. by Nicolas Lubitz & Barbara Wueringer

by | Dec 10, 2018 | Blog

written by Nicolas Lublitz and Barbara Wueringer

Sawfish are the stuff of legends: Animals that can grow up to 7 m long and have an extended rostrum (the ‘saw’) loaded with teeth. Old newspaper articles have described them as monsters that lurk in our rivers and oceans and are just waiting to attack people. Quite the opposite is true, as sawfish use their „saw“ skillfully in order to stun and manipulate their fishy prey, not caring for us humans. They are magnificent animals, no doubt.

Anecdotal reports claim that sawfish used to be so plentiful that people in Sudan once used their rostra as fence posts. Additionally, a study from Lake Nicaragua estimated that between 1970 and 1975 around 60,000 – 100,000 animals were caught in the lake by commercial fishers. This was once thought to be their largest population. A survey in 1992 could not find traces of a single individual in the lake.

Today, five extant species are recognized. All are either listed as Critically Endangered or Endangered under the criteria of the IUCN, making sawfishes the most endangered of all the sharks and rays in the world. Four out of those five species can be found in Queensland waters, which are thought to be home to some of their last important populations in the world. With significant global declines for all species, the question arises, if the rivers and coastlines of Queensland are still a stronghold for these animals?

First, we need to engage in a debate about our baseline – how abundant was the species in the past? This search can turn philosophical really quickly. How do we determine a healthy population? What levels do we want the population to return to? Does it need to return to pre-human influence levels or is it enough to keep the population at a level where it can somewhat perform its ecological function? Or is exploitation more important than conservation?

Secondly, we need to determine how much the population of sawfish have declined in Queensland. To answer this, sawfish capture data from the Queensland Shark Control Program (QSCP) was analysed. This program started in 1962 and aims to protect swimmers/surfers from potentially dangerous sharks by utilizing gillnets and baited drum lines. Although no scientific evidence exists that the program actually works, it has been in place for decades.

The data shows that between 1962 and 2016, 1450 sawfish were captured,with 99% of captures occurring in the four most northern areas of Queensland’s East Coast, suggesting the existence of critical habitat. Most animals were caught in the nets and not on drum lines.

An overall decreasing trend in catch rates was observed for two locations where standardized catches could be calculated. However, standardized catch rates from the data set are likely underestimating abundances, as the nets were set up to 500m away from the coast, in deep waters where they often did not reach the bottom. Most sawfish captures occurred near the bottom of the nets.  

The facts of this data set make firm conclusions on abundance declines difficult, although it is apparent that the declines have been statistically significant. We need to devote more resources to better understand population trends in Queensland’s sawfishes.

 

You can access the publication on sawfish catches in the Queensland Shark Control Program here.

This blog post was originally written for the Save Our Seas Foundation. Access the original blog here. 

Standardized catch rates for sawfish (fam. pristidae) in gill nets in two separate locations of the Queensland Shark Control Program, 1962 – 2016. Red stars indicate when fishing began and ceased in the respective location.