Who Is Waterkeeper: Dr. Michelle Ryan, Hawkesbury-Nepean Waterkeeper
By: Thomas Hynes
As a child, Dr. Michelle Ryan spent a great deal of time on the Hawkesbury-Nepean River in Eastern Australia, either out fishing on her dad’s boat or relaxing on the river’s banks with friends after school. Today, it is a place where she takes her own young daughter to appreciate nature. Michelle studied environmental management and aquatic ecology at school which led to a career in academia at Western Sydney University. It was there that she became a “loud advocate” for the river. In 2019, Michelle was nominated to be the Hawkesbury-Nepean Waterkeeper, a role she proudly accepted.
The Hawkesbury-Nepean River runs about 470 kilometers, or roughly 292 miles, and its catchment covers over 20,000 square kilometers, or nearly 8,000 square miles. The area is deemed to possess world heritage significance and is home to significant biological diversity. There are jellyfish and spoonbills, kookaburras and mullet, cockatoos and bull sharks. However, the most intriguing and enigmatic animal in the Hawkesbury-Nepean area – and possibly anywhere in the world – is the platypus.
To say the platypus is an anomaly would be an understatement. They are one of the only mammals to lay eggs. Mother platypuses feed their young milk. However, they don’t have nipples, and instead secrete milk from pores in their skin which the young platypus, also known as puggles, lap up for sustenance. Platypus are only one of a handful of mammals to produce venom. There are no reported human deaths from platypus venom, but there are also no known cures or treatments either. 
Platypus have a beaver-like tail and a duck-like bill that is packed with electrorectors that allow them to prey underwater by detecting electric fields, which is helpful since they close their eyes (and ears and nostrils) when they dive into water. Not surprisingly, the platypus was considered a hoax when it was first discovered. Many scientists — perhaps reasonably — believed that the animal was contrived by combining the parts of several different animals.
Of course, the platypus is in fact a real animal. Though there was some skepticism that it still persisted in the Hawkesbury-Nepean catchment.
“The last record of platypus in the area was 1998. So they basically thought we didn’t have platypus, so they didn’t need to consider that in development applications. They didn’t have to really think about that with regard to waterway health,” says Michelle. “But the community group knew they had platypus. Fishermen were seeing platypus. They had landholders who have houses along the creeks telling them that they had platypus. They said what can we do? How can we show that we have platypus?”
Michelle and her team began looking for DNA evidence. Platypus, like humans, leave traces of skin and hair everywhere they go. Michelle and citizen scientists took water samples and sent them to be analyzed. They were able to determine if a platypus was within a kilometer of the test site within the last 24 hours. What they found was that half of the sites (18 out of 36) showed the presence of platypus.
“That kind of blew our mind,” says Michelle. “We thought we might get one or two. But it really seemed like that creek of our main Hawkesbury Nepean River, and the small little tributaries that came off, had platypus. So it was really exciting. And then that kind of just exploded my work into platypus more, and that’s what I spend the majority of my time doing now, which is great.”
Platypus are elusive and very hard to spot. They nest in burrows during the day and come out around sunset. They forage for about 12 hours, where they collect between 25-50% of their body weight in water bugs, and then return to their burrows at sunrise. That means Michelle and her colleagues become nocturnal for almost half of the year.
Michelle undertakes all this work not just because she is curious to know if there are platypus. Rather, these critters are an indicator of water quality. Their popularity can also help encourage human residents to be better stewards of the environment.
“The platypus is an icon for waterway health and it’s our way of connecting people to our waterways and getting governments and industry and communities on board to protect this amazing species,” says Michelle. “Protecting the platypus protects all the waterway species. What’s good for the platypus is good for bass. It’s good for mullet, it’s good for eels, it’s good for all those water bugs. It’s good for all those tiny zooplankton, and it’s good for our human health too. Not just our drinking water, which a lot of our drinking water comes from the Hawkesbury–Nepean. But also having recreational space, people being able to access the river, go boating, going swimming, going kayaking. Mentally it’s amazing having these healthy waterways around us that we have somewhere to go. We have somewhere to relax and we have somewhere to connect with.”
Michelle’s work extends beyond nighttime platypus hunts. She also helped secure significant funding to launch the Resilient Rivers for Resilient Hawkesbury Platypus Populations project. This initiative turns years of research and community partnerships into real, on-ground action, creating a network of ‘Platypus Parks’ that restore habitat, improve river health, and strengthen ecological resilience. What makes this project especially meaningful is its foundation in collaboration – working alongside First Nations peoples, landholders, and local communities to care for waterways and protect one of Australia’s most iconic species.
Looking beyond her catchment, Michelle is grateful for her fellow Waterkeepers in Australia and beyond. There are immediate and practical benefits to the network, such as sharing information, asking questions, and troubleshooting. But, there is the larger and more abstract benefit of inspiration too.
“No matter where you are in the world, you can make a difference,” says Michelle. “Water is life and every living thing needs healthy water to survive. Simple actions you take in your home, at school, at work can have a huge impact on waterway health. Anyone can make a difference.”