Amazon Megafish Migration Project & International Sawfish Day
October 17, 2020

The Amazon region, both within the Amazon River and along coast north and south of the river, is home to numerous large, migratory fishes. One of these fishes, the largetooth sawfish, has been the recent focus of the EcoWB Amazon Megafish Migration project. And, with International Sawfish Day on October 17 th , and World Fish Migration Day on October 24 th , now is the perfect time to highlight the work being done by the Megafish team.  

Largetooth sawfish are a critically endangered species worldwide, listed on the IUCN Redlist of Threatened Species. They are also fascinating, both because of their unique body plan and because they are somewhat of a scientific mystery. Sawfish are a type of ray, though their body shape, with prominent dorsal fins and tail fins, means they are often mistaken for sharks. Their rostrum bordered by sharp rostral teeth is a unique adaptation that they use to both sense and hunt prey.  

From left: Dr. Patricia Charvet, Dr. Jens Hegg, Mariana Moro in Curitiba, Brazil holding sawfish rostrum samples from the Amazon region.

Largetooth sawfish are a euryhaline species, able to tolerate a range of salinities. They are sometimes known as Freshwater Sawfish because they are often found in rivers as well as in brackish environments. However, most of the current data on largetooth sawfish comes from Australia where their numbers are still somewhat plentiful. The Amazon region is thought to be one of the last refuges for the species in the Americas, but we know very little about their numbers or their behavior and ecology in this part of the world.  

The EcoWB team is working to better understand largetooth sawfish in the Amazon region using chemistry. Partnering with researchers in Brazil including Dr. Patricia Charvet, Dr. Tommaso Giarrizzo, and Dr. Jorge Nunes, Dr. Jens Hegg has identified and collected over 100 sawfish rostral teeth. Because the teeth grow throughout the life of the fish we have discovered that they record chemistry, particularly chemical records of salinity, which might allow us to better understand their distribution and behavior. The preliminary findings are currently in review and a pre-print of this work can be found on BioRxive.  

Study area used to create the GIS model.

The Megafish team has been hard at work this year collaborating with the EcoWB GIS Program to support this work. In order to reconstruct the chemistry within our sawfish samples it is important to understand the spatial variation of chemistry across the area being studied. This helps to narrow down the likely locations where sawfish may have travelled throughout their life, and better understand how these movements across fresh and brackish water relate to other important parts of their life-history. All of this, eventually, can help us understand more about the behavior and distribution of largetooth sawfish in the Amazon river and along the Brazilian Amazon coast.  

To this end the EcoWB GIS Program has helped to identify temperature, depth, and salinity datasets which can be used to characterize the potential habitats of largetooth sawfish in the Amazon region. In the coming months the team will be building these datasets into a GIS model that can be used to inform the chemistry we find in the sawfish rostral tooth samples we are working to import and analyze.

From left: Dr. Tommaso Giarrizzo, Dr. Jens Hegg, PhD Student Leonardo Feitosa, Dr. Jorge Nunes collecting donated rostral tooth samples near São Luis, Brazil.

 

By ECOWB ECOWB • October 5, 2026
Meet Dune Ives, EcoWB’s new Executive Director . Since stepping into the role earlier this summer, Dune has been getting to know the people, partners and projects that make EcoWB what it is – and thinking about what’s possible as we look to the future. Dune brings more than 25 years of experience turning ambitious environmental ideas into action. Her work has included the Green Sports Alliance and NextWave Plastics, developing with TOM FORD the first impact investment fund and awards program to replace thin-film plastic, and leading work recognized with the inaugural UN SDG Impact Award. We sat down with Dune to hear what drew her to EcoWB, what has surprised her in her first couple of months as Executive Director, and what excites her most about where the organization is heading. From the extraordinary people who built EcoWB to the potential of its global volunteer community, Dune reflects on what makes this organization special – and what she hopes will come next. What first attracted you to Ecologists Without Borders? When I first became aware of Ecologists Without Borders, I was struck by its unique offer to the world. Throughout my career, I’ve held the belief that creating a healthy, liveable planet is everyone’s job – and that is what I saw reflected in EcoWB’s model.. There are many organizations doing environmental conservation and restoration work – whatever name you put to it. But what felt unique to me is the way that Ecologists Without Borders has harnessed the zeitgeist of a service economy, bringing together experts from around the world: scientists, biologists, ecologists, marketing professionals, and everything in between. As humans, we are hard-wired to rush to the aid of other humans, but we can feel hopeless and rudderless in the face of environmental degradation, especially when it happens in faraway places. What I love about EcoWB is that it gives people a way to help. It enables communities to complete the work they know needs to happen to create healthy environments in which their communities can thrive. No other organization does this. I wanted to be part of this effort: to harness the power of volunteers who have passion, drive, commitment, and something to give beyond themselves and their day-to-day lives, and to put that power to work for communities all over the world. And what an exciting way to give back to the environment and to know – not just feel, but know – that you are making a difference every day. What surprised you most when you joined the organization? When I first got under the hood of the organization, what surprised me was that it had been volunteer-led for nearly its entire existence. I knew that I was the first staff Executive Director. I didn’t realize at the time that this organization, which began in 2011, had been developed, overseen, managed, and implemented by a group of some of the most passionate – and nicest – humans I have ever met. When you step into the role of Executive Director in a primarily volunteer-led organization, it is important to recognize that you are carrying all of their hopes and dreams, as well as those of the people who came before them, who established the organization and continued to propel it forward. That is an important reminder of my role as Executive Director, and of the history and culture I am helping to carry forward. What makes EcoWB’s volunteer model so powerful? What is powerful about EcoWB’s model is that there is a place for everyone in this story. There are so many environmental, conservation and restoration needs around the world. A project in one part of the world might require someone who is excellent at youth education and leading eco-tours. Another might need somebody who has just completed a master’s programme, has a speciality in GIS mapping, and wants to put that expertise to work. Another might need someone who really understands what a wetland could look like when it is fully restored. There is a place for everybody at Ecologists Without Borders, and that is what I think is so powerful about this model. What do you want the volunteer experience at EcoWB to feel like? I want volunteering with EcoWB to feel meaningful. When you come here, I want you to know that your talents, your time, your experience, and your expertise are not only valued – they are honoured. We believe deeply in our model and in the way we engage with communities, but we’re also learning. As EcoWB grows, we want to keep learning – from our partners, from the projects themselves, and from the volunteers who bring their experience and expertise to this work. Where do you hope EcoWB will be a year from now? A year from now, I hope we will be talking about how our volunteer base has quadrupled, and how the number of communities we have served has increased tenfold – if not more. When we do this right, we will be able to match volunteers with communities that don’t currently have access to the technical expertise or funding they need. We will be able to grow our collective impact in every corner of the world. And now is the right time to do it. Communities are not waiting – and can’t wait – for the large NGOs to solve all of their environmental challenges, and we should not wait either. We need to match the pace and scale of what these communities are asking for. What would you say to someone considering getting involved? I hope you’ll join us, and I’m really excited to see what we are going to build together.
By ECOWB ECOWB • April 28, 2026
We’re excited to share our 2025 Annual Report—a snapshot of a year where EcoWB continued to grow, respond, and deepen our work alongside communities around the world. Inside, you’ll see what this community has made possible—from supporting the establishment of a Community Forest in Cameroon to advancing projects across fisheries, wetlands, and restoration in Mexico, El Salvador, Costa Rica, and beyond. You’ll also get a closer look at some of the volunteers behind the work, and how their time and expertise are helping turn complex challenges into practical action. EcoWB 2025 Annual Report Importantly, this momentum is carrying forward. New projects are already underway in 2026, more are taking shape, and we’re continuing to respond as communities reach out for support. We’re proud of what’s been achieved—and even more excited about what’s ahead. Click HERE to download the full report.