Ecuadorian PhD student Andrea Varela shares her experience investigating the impact of El Niño on marine iguanas in Galapagos with the support of the NGO Captain Darwin.
Andrea is an Ecuadorian Biologist with a passion for conservation and herpetology. Andrea joined the Iguanas from Above team in November 2019 and is the PhD student of this project.
Captain Darwin is an NGO dedicated to documenting environmental and biodiversity changes in the places visited by world-famous naturalist Charles Darwin during his voyage on the HMS Beagle 189 years ago. This NGO provides logistical support, through the use of its vessel, to local researchers at each stop on Darwin’s historic voyage.
During his visit to the Galapagos, Darwin was impressed by one species in particular: The Galapagos marine iguana. Two hundred years after Darwin’s visit, this species continues to fascinate scientists, such as myself, an Ecuadorian PhD student, who conducts research on marine iguanas.
I am part of the research team for the project “Ecology of Marine Iguanas (Amblyrhynchus cristatus) of the Galapagos Islands (PC-01-24)”. This project is led by Universidad San Francisco de Quito (USFQ) and the University of Leipzig, with the Galapagos National Park Directorate as its counterpart. The project involves monitoring the population status and studying the ecology of the marine iguana’s diet.
This year, the project had the support of the Captain Darwin crew and Galapagos Conservation Trust to carry out an expedition in the Archipelago and continue research on marine iguanas during the El Niño climatic event.
I participated in the first phase of the expedition, sailing for 20 days around the Western Galapagos Islands from April to May 2024. My mission was to monitor the population status of the main marine iguana colonies during El Niño using drones. This is a follow-up study of the Iguanas from Above project, which has been using drones for the past few years to conduct a census of the species. The data from this expedition will help both myself and local managers to understand the impact of El Niño on marine iguana colonies.
The time just before setting sail is always crazy! The boat was prepared, our permits were approved and we had a ranger from the Galapagos National Park ready to accompany us. On the day of the voyage, we woke up early to pick up our luggage from quarantine and head to the boat aiming to set sail at 8 am, which ended up being 10 am. Sailing always takes longer than planned!
We started our journey towards an area north of Santa Cruz island. Excitement spread across the team, which besides myself included Susana Trujillo (National Park ranger), Víctor Raoult (captain), Félix Gouniot (cameraman), Rubia Cecilio (crew member) and Eduardo Sampaio (researcher).
The activities planned for the coming days were collecting marine iguana faeces and algae samples (the iguana’s main source of food) for my colleague Denisse’s project, counting dead iguanas and flying drones to collect aerial photos and videos which we use to count individuals and monitor their movements on land and in the sea.
We started our day early as we had lots of activities to get through. Susana was very helpful in collecting the samples while I flew the drone. The marine iguanas on this island prefer to spend their time in a mud lagoon, feeding from surrounding plants, meaning we saw very few iguanas in their usual rocky coastline habitat. Thankfully, we didn’t find any deceased iguanas in this colony. Our research into their diet will help us determine how iguanas adapt to climatic events, such as El Niño, that reduce their food availability.
Our second sampling site was Sombrero Chino (Chinese Hat), an islet off Santiago. The marine iguana colony at this site was pretty small and therefore difficult to find. This time, we enlisted the help of Eduardo and Félix. My job was to fly the drone from the boat and capture footage of the entire island. Sombrero Chino is a popular destination for tourists. We therefore had a great opportunity to engage them with our work.
The following day, we continued to the black lava shoreline of Puerto Egas on Santiago. Puerto Egas has a moderately abundant marine iguana colony and is a popular site with tourists. We carried out our algae collection and iguana faecal sampling and then got ready for our 12-hour journey to Puerto Villamil, a small port village located on the southeastern edge of Isabela. That night, all of us took two-hour shifts navigating the boat which was a fun experience.
Iguanas from Above is an innovative project that combines drone technology with citizen science to monitor the health of marine iguana populations in Galapagos.
After a long journey sailing through the night, we arrived at Isabela. We planned to spend four days at this next site so that we could film iguanas swimming! Our new site also allowed us to study iguanas in an urban environment. We saw a group of iguanas that had decided to make their home in ‘Iguana Rock’, a popular bar in the town, where the owner (Claudia) provides shelter and protection from potential attacks from dogs and cats.
Sadly, in Tintoreras, we discovered our first deceased iguanas that showed obvious signs of starvation, likely caused by the current El Niño climatic event.
The next stop on our trip was Cabo Douglas, northwest of Fernandina. I have been lucky to visit this site four times and I love it. The iguanas here are so abundant that they live on top of each other. This island is free of invasive species which helps to protect the colony and helps it remain an area of high biodiversity.
We stayed at this site for four days to dive and film marine iguanas underwater. Cabo Douglas is a top site for diving with iguanas, so I felt incredibly lucky to be able to do so for research purposes. Over three days, we dived and recorded the iguanas’ movements underwater and their feeding habits.
Punta Espinosa is one of the most beautiful places in Galapagos and is home to a large population of marine iguanas. Unfortunately, once again, we observed the ongoing effects of El Niño with dozens of deceased iguanas. Punta Espinosa is also a tourist site, so we saw many concerned tourists. It seems that in more abundant colonies, competition for scarce resources is greater, resulting in more deaths. It will be very useful to know how this colony (and others) continues to fare towards the end of the year to better understand the impacts of El Niño.
With the first half of the expedition drawing to a close, we returned to Isabela to visit a different sampling site. This site differs from our previous Isabela site on Isabela as here the iguanas live on the cliff, so we had to climb to reach them! We collected the drone footage of the population from the boat. In the project I work for, Iguanas from Above, we have confirmed that flying drones allows us to monitor difficult sites like these safely. A unique moment here was seeing our first iguana hatchling, signalling the start of the hatching season!
Finally, we arrived at Punta Mangle on the eastern side of Fernandina, our last stop on my journey with the team. Here, I gave a formal interview about the expedition and the work I’ve been doing and then the whole team went out to collect data. I felt sad as we neared the end of the day, knowing my time on the expedition had come to an end. But I was also relieved at how well the trip had gone, ready to start analysing my data and excited for my colleague Denisse who was joining the team on the second part of their expedition!
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