Two extraordinary sawfish rostrums are helping marine biologists at Southern Cross University uncover vital information about species that once thrived in Australian waters.
Quick facts
What is a sawfish rostrum? A rostrum is the saw-like snout of a sawfish, lined with teeth used for hunting and defence.
Why are sawfish endangered in Australia? Sawfish face threats from habitat loss, overfishing and slow reproduction rates, making population recovery difficult.
How does DNA analysis help conservation? DNA sampling reveals population links and genetic diversity, guiding strategies to protect remaining species.
Origin of rare sawfish specimens
There are five sawfish species known around the world, and four are found in Australia. All are critically endangered.
Green sawfish were once common in waters off the coast from northern Australia as far south as Sydney, but they are now classified as extinct in New South Wales.
The last confirmed sighting of a sawfish in NSW was in the Clarence River, Yamba, in 1972. That's only 90 minutes away from where they're now being studied by marine biologist Adrienne Gooden, PhD candidate at Southern Cross University and volunteer with non-profit research organisation Sharks and Rays Australia (SARA).
This research began with a green sawfish 'saw', or rostrum, donated to the Southern Cross University National Marine Science Centre in Coffs Harbour, NSW.
"We use rostrum length to estimate body size, which means this green sawfish measured about 3.4 metres when it died. At that size, we know the animal had only just reached sexual maturity," said Ms Gooden.
Sawfish take many years to grow, making them highly vulnerable to overfishing and habitat loss. While our understanding of juvenile sawfish is expanding, there is still much to learn about adult sawfish.
"This sawfish specimen represents a species that used to live right here, and died on the edge of adulthood. It shows how vulnerable these species are, and it's also a reminder of what we've lost," said Ms Gooden.
/prod01/channel_8/media/scu-dep/news/images/2026/sawfish-2.jpg)
Why sawfish research matters for conservation
Many rostrums were originally kept as decorative trophies. Today, they provide rare opportunities to study species that have disappeared from local waters.
DNA sampling is underway using non-invasive techniques that work even on century-old specimens. Analysis can reveal information like population links and genetic diversity, which helps scientists understand how and where species lived, and what might have contributed to their decline.
"Adding this DNA information to the database means we're filling in the gaps in our knowledge about these species. Historical data can change what we think we know, and help us target conservation in the right places," said Ms Gooden.
Future of sawfish protection and research
The information collected from the saws will be added to the Sharks and Rays Australia Sawfish Database – the largest data set on sawfish distribution in Australia.
The database holds information on more than 3,000 sawfish Australia-wide and spans more than 100 years of records, drawn from sources including DNA sampling, reported sightings, and historical records.
In one case, old newspaper records revealed cases of large, adult freshwater sawfish occurring in the Brisbane River. This allowed scientists to expand their known historic range by 800 kilometres.
"That discovery prompted new sampling, which is critical for mapping habitats and planning conservation strategies. Piecing together sightings, historical data, and sampling means we can better identify threats and safeguard these species," said Ms Gooden.
Partnering with City of Coffs Harbour Libraries, Ms Gooden developed the Young Marine Biologist Program to help high school students understand the transformative role research can play in protecting our planet.
"Sharing local stories and experiencing hands-on fieldwork are great ways to get curious brains thinking about what mysteries they might like to explore. The sawfish is a great example," said Ms Gooden.
"Sawfish have been evolving for 450 million years. Understanding them is key to making sure they don't disappear."
Help contribute to historical understanding of sawfish
Sharks and Rays Australia are seeking information from the community to increase knowledge and understanding of the historic range of sawfish. Historical documents such as saws, newspaper articles, photographs or personal records can be submitted to:
- SARA sightings app (iPhone only)
- SARA sightings online portal
- 1800 CYTAGS.
Main image: A large female green sawfish being rescued after getting caught in a fisherman's net in the Tweed River, 1969. Photo credit: Sharks and Rays Australia.
