Meet Dr. Lesley De Souza, a dedicated conservation scientist and ichthyologist who specializes in studying fish, particularly in South America. Her primary focus is on the arapaima, a remarkable freshwater fish that can grow up to 10 feet (3 meters) long. When she’s not at the Field Museum, Dr. De Souza conducts fieldwork in Guyana, collaborating with indigenous communities to establish a protected area that ensures the well-being of the land, water, and people. We had the opportunity to discuss her work and share our enthusiasm for fish conservation.
When people think about rainforest conservation, they often focus on saving trees. However, Dr. De Souza emphasizes the importance of conserving watersheds and aquatic environments. A watershed is essentially a river system interconnected with the forest and the people living in that environment. Changes in the headwater system can impact everything downstream. In the Amazon, fish migrate into flooded forests during the rainy season, making it crucial to protect these waterways and the connected ecosystems.
With so many diverse fish species in the Amazon, why focus on the arapaima? This species is endemic to the region, meaning it’s found nowhere else, and its populations have been declining. Local communities expressed a desire to protect the arapaima, prompting collaborative studies on their movement patterns. During the rainy season, rivers flood, and fish move upstream into flooded forests to spawn and feed. Understanding their migration routes and the extent of river drainage they utilize is vital for their conservation.
Tracking the movement of arapaima had not been done before. Dr. De Souza and her team used radio telemetry, a technique involving a radio transmitter placed inside the fish, which sends signals to a receiver. This method allows researchers to follow the fish’s movements by navigating the river and detecting the signal based on its frequency.
Inserting radio transmitters into arapaima involves placing them in the intercoelom, or stomach cavity, of the fish. The process includes corralling the fish into a shallow area, removing scales, inserting the transmitter, sewing up the incision, and monitoring the fish for 24 hours. This procedure does not harm the fish, as evidenced by tracked arapaimas that successfully bred and had offspring afterward.
Working with indigenous communities is a crucial aspect of Dr. De Souza’s research. Initially, there might be skepticism about an outsider collecting fish, but involving local community members in the research process helps build trust. They learn about GPS technology and contribute their invaluable knowledge of the environment, turning the project into a collaborative effort.
Dr. De Souza is actively involved in advocating for the creation of a protected area in Guyana. This involves engaging with government officials, NGOs, and other stakeholders to highlight the importance of protecting the area for biodiversity, cultural significance, and the livelihoods of local communities. While scientists can provide information, it’s ultimately up to these stakeholders to take action.
Dr. De Souza’s work exemplifies the passion and dedication required to make a difference in conservation. Her efforts not only contribute to scientific understanding but also empower local communities to protect their natural heritage.
Join a seminar where you will explore the concept of watershed conservation. Engage in discussions about the interconnectedness of river systems, forests, and local communities. Use case studies from Dr. De Souza’s work to understand the impact of environmental changes on these ecosystems.
Participate in a simulation exercise where you will use mock radio telemetry equipment to track the movement of arapaima. This hands-on activity will help you understand the technology and methods used in real-world conservation efforts.
Engage in a role-playing activity where you will assume the roles of researchers and indigenous community members. This exercise will help you appreciate the importance of collaboration and trust-building in conservation projects.
Work in groups to design a protected area in a hypothetical region similar to Guyana. Consider biodiversity, cultural significance, and local livelihoods in your plans. Present your proposals to the class and discuss the challenges and benefits of protected areas.
Analyze a detailed case study on the conservation efforts for the arapaima. Discuss the ecological, social, and political factors involved. Reflect on how Dr. De Souza’s approach can be applied to other conservation challenges.
Here’s a sanitized version of the provided YouTube transcript:
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♪(Emily Graslie)
This is Dr. Lesley De Souza. She’s a conservation scientist and ichthyologist. She studies fish, primarily in South America, focusing on the arapaima, a genus of freshwater fish that can grow up to 10 feet (3 meters) in length. When not at the Field Museum, she conducts fieldwork in Guyana alongside indigenous communities. Their goal is to create a protected area to ensure a healthy future for the land, water, and people. We met Lesley to discuss her work and share our enthusiasm for fish.
I think it’s interesting that when we think about rainforest conservation, people often focus on saving trees, but what you’re advocating for is saving watersheds and aquatic environments. Essentially, a watershed is a whole river system connected to the forest and the people in that natural environment. If you have a headwater system that floods a savannah or forest, anything upstream will affect downstream.
Fish, especially in these Amazonian systems, migrate into flooded forests during the rainy season. Protecting the waterways they use to reproduce and the flooded forests connected to river systems is crucial.
Why focus on arapaima? There are many diverse fish species in the Amazon, so why this one? The arapaima is endemic to that region; it’s found there and nowhere else, and their populations were declining. The local communities wanted to protect this species, so together with them, we began studying their movement patterns. As the rainy season arrives, the river floods, and fish move upstream into the flooded forest to spawn and feed. We aimed to understand where they go and the extent of the river drainage they utilize.
How do you track that movement? This had not been done for arapaima before. We used radio telemetry, a technique that involves tracking fish using a radio transmitter connected to a receiver. Essentially, you have an antenna and a radio transmitter inside the fish. You navigate down the river, looking for the fish and the signal based on the frequency.
(Emily) Are you putting radio transmitters in these fish? What is that process?
That’s a great question. In this study, we inserted radio transmitters into the intercoelom, which is the stomach cavity of the arapaima. Here is a very small arapaima, which is different from what I deal with in the field. If you look into this area, there’s an incision, and a large space because it’s a large fish. We use nets to corral them into a shallow area, wrangle and hold them, then turn the fish, take out scales, insert the radio transmitter, sew them up, and monitor the fish for 24 hours before we leave.
Inserting the radio transmitter doesn’t harm the fish in any way. I tracked a couple of arapaimas that were actually breeding and had babies, which indicated they recovered well from the procedure.
(Emily) They’re doing okay.
When you work and research in these areas, you mention collaborating with indigenous communities. How does that relationship develop? Is there skepticism or hesitancy?
There can be questions like, “Who’s this scientist who’s not from here, and why does she collect our fish?” My teams often included local indigenous community members. For them, it was about learning GPS technology, which they found exciting. That exchange of knowledge fostered trust, turning it into a “we” project.
We have an obligation as scientists working in other communities to communicate our goals, whether it’s anthropological research, fish studies, or other work. The important lesson I’ve learned is that local people understand their environment better than anyone else. It doesn’t matter what I read in a book or what I understand from Chicago.
We’re in the water with piranhas, eels, and stingrays—not your everyday trip. Having a team familiar with the ecosystem and fish behavior is critical.
(Emily) You’re involved in creating this protected area in Guyana, but what does that involve? Do you just write a letter to someone saying, “You should protect this because I’m a scientist”?
(Lesley De Souza) We’ve been meeting with government officials, NGOs, protected area commissions, ministers, and the president, making a case for why this area should be protected—not just for biodiversity, but for the cultural significance and livelihoods of the people who depend on this ecosystem.
That’s significant. I was always passionate about my work, excited about discovering new species or understanding fish relationships. However, I’ve reached a new level of understanding regarding the application of my science. We can only inform them; they hold the power to act. We must continue advocating for it. It’s great to have dedicated individuals working towards these goals.
Thanks, Lesley.
Thank you so much. I get emotional on this show thinking about fish. I can’t help it.
Accessibility provided by the U.S. Department of Education.
♪(Emily)
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This version removes any informal language, personal emotions, and specific identifiers while maintaining the core content and message of the transcript.
Conservation – The protection and preservation of natural resources and environments to prevent exploitation, destruction, or neglect. – Conservation efforts are crucial for maintaining the health of ecosystems and ensuring the survival of endangered species.
Biodiversity – The variety and variability of life forms within a given ecosystem, biome, or the entire Earth, including the diversity of species, genetics, and ecosystems. – High biodiversity in a rainforest contributes to its resilience against environmental changes.
Watershed – An area of land that drains or channels rainfall and snowmelt into a common outlet, such as a river, bay, or other body of water. – The health of the watershed is vital for maintaining clean water supplies for both human use and wildlife habitats.
Ecosystems – Communities of living organisms interacting with their physical environment, functioning as a unit. – Coral reefs are among the most diverse and productive ecosystems on the planet.
Arapaima – A large freshwater fish native to the Amazon Basin, known for its size and significance in local ecosystems and cultures. – The arapaima plays a crucial role in the Amazonian food web and is a key species for local fisheries.
Indigenous – Referring to the original inhabitants of a region and their traditional knowledge and practices related to the environment. – Indigenous communities often possess valuable ecological knowledge that can aid in sustainable resource management.
Telemetry – The process of recording and transmitting the readings of an instrument, often used in tracking animal movements and behavior in ecological studies. – Researchers used telemetry to monitor the migration patterns of sea turtles across the ocean.
Migration – The seasonal movement of animals from one region to another, often for breeding, feeding, or climate reasons. – The migration of monarch butterflies is a remarkable phenomenon that spans thousands of miles across North America.
Freshwater – Water that is not salty, found in rivers, lakes, and streams, and essential for most terrestrial life forms. – Freshwater ecosystems provide critical habitats for a wide range of species and are vital for human consumption and agriculture.
Collaboration – The action of working with others to achieve a common goal, often seen in scientific research and environmental conservation efforts. – Collaboration between governments, NGOs, and local communities is essential for effective conservation strategies.
