U.S.-based scientists use drones to map and classify wetlands in Gabon.
One of the benefits of such a large organization is the sheer amount of talent that exists under one “virtual roof.” When the Africa Program took on the monumental task of mapping Gabon’s entire freshwater system, we only had to look around the organization to find the expert help we needed!
The Oregon Chapter’s Allison Aldous and the Caribbean Program’s Steve Schill recently traveled to Gabon to assist our staff in mapping and classifying a set of wetlands. Their secret weapon? A drone, which allowed the team to work from a boat on the Ogooué River rather than traversing through Gabon’s notoriously dense — and potentially dangerous — wetland habitats.
Here, Allison and Steve share the details of their high-tech adventure.
Tell me a little bit about what you do at TNC.
Allison: I am the senior freshwater scientist for TNC’s Oregon chapter. I also dedicate about 15 percent of my time to work in Gabon. For the Oregon part of my job, I work on groundwater protection; resilience of freshwater ecosystem to climate change; coastal (estuarine) wetlands; and measures and monitoring.
Steve: I am a senior scientist for TNC’s Caribbean Program. I spend a lot of time mapping what’s underwater and getting that information in the hands of decision-makers so that they can make the best decisions on how to protect their marine habitat.
Tell me about this project in Gabon and how you got involved.
Allison: Our goal is to use a combination of remote sensing technology and field observations to develop a map of a massive wetland landscape. This map will then be used to develop management plans and make decisions about sustainable development in the coastal plain of Gabon. In other words, you can’t manage this area without knowing what is there!
Steve: Allison and I both started working in Gabon several years ago to help develop the country’s Freshwater Atlas, and our involvement has continued. The Africa Program was looking for a French speaker who had experience in GIS. I also work in Haiti and love working with Francophone countries — it was a perfect fit!
Allison: This project mapping Ramsar wetlands is a great fit for me. My Ph.D. is in wetland ecology and I have done a lot of work classifying wetlands in different parts of the world and developing management plans for them.
What was a typical day on this expedition like?
Allison: A typical field day lasted 10-12 hours. We would start around 7 am and travel for anywhere from 30 to 90 minutes to the area selected for sampling that day.
Steve: Once we arrived at the survey area, I’d send up the first drone to do an exploratory mission. Allison would watch the live video feed through a special headset. She’d ask me to fly it over the different wetlands to get a sense of how well what we were seeing matched the draft map that had been developed ahead of the expedition.
Allison: Based on what we saw during the exploratory flights, we would set up flight line transects for the second drone mission. These transects were designed to fly over the target wetland types at 80 meters altitude while taking photos at three-second intervals.
Several times, we were able to find an open dry area along the river bank to launch the drones. This gave us the opportunity to look more carefully at the wetland soil, plants, and water chemistry, which is very helpful for in classifying the wetlands.
What was the most challenging part of working in this landscape?
Steve: Launching and landing the drones from the back of a boat was challenging. We brought twelve drone batteries with us and they had to be fully charged each night. Each battery gave us about 12 minutes of flight time so another challenge was completing the mission and landing back on the boat before the batteries ran out! .
Allison: The heat is the obvious answer, but actually the water ends up being super challenging. We are a freshwater conservation program, so we love water, right? But sometimes it’s not deep enough for the boat, sometimes it’s too deep to walk in, and most of the time there was too much water to land on dry ground.
What was the coolest part about working in this landscape?
Allison: As a wetland ecologist, it is rare to have the chance to see firsthand a large expanse of wetland that has largely not been diked, dredged, dammed, diverted, contaminated, harvested, or invaded by exotic species or any of the other ways we have found to alter wetlands. I’m not saying it doesn’t have problems — but the scale of those problems doesn’t compete with the intactness of the landscape.
Tell me about a time on the trip when you had to get resourceful.
Allison: In my USA life, I rarely drink soda. But in hot and humid Gabon, a Coca-Cola sure tastes good. One of the times we landed at a small cluster of homes, [Gabon Program Director] Marie-Claire Paiz disappears into one of these houses and emerges a few minutes later with cold bottles of soda. Boy that went down well!
Steve: We’ve never had to operate from the back of the boat so we weren’t sure how it was going to work. But it actually worked pretty well. I wouldn’t recommend this landscape for a novice drone pilot, however!
What was the most interesting thing you observed about the wildlife or the culture of Gabon?
Allison: Other than the cities of Port Gentil and Lambarene, people are very dispersed in this area. Everywhere we went, people were fishing, tying fish nets, selling fish, or eating fish. At TNC we are always talking about the importance of ecosystem services to public health and local economies, and nowhere is this more apparent than in the Bas Ogooué.
How do you hope these data will make a difference for Gabon?
Steve: Maps are an important part of management. You need to know what’s there in order to make decisions. By developing the first accurate wetland map of the region, we hope to initiate a discussion of the ecological and ecosystem service values in this area, and provide a baseline from which to create a management plan and track changes over time.
What was your biggest takeaway about conservation in Gabon?
Allison: This is a critical time in the country’s history. The government is looking to other natural resources to take the place of fossil fuels. If the government is true to its commitment to sustainable development, we can play a pivotal role in making that happen.
Photos: © Courtesy of Steve Schill/TNC. From top: The drone used on the expedition; Steve Schill (left) and TNC volunteer George Raber set up the drone; Allison looks in the viewfinder while Steve operates the drone; Allison collects soil data; shopping at a local market in Port Gentil.
