

Iguanas from Above: Citizen science in action
Find out how marine iguanas have become the subject of one of the most innovative citizen science projects in the Galapagos Islands.
Marine iguanas, one of Galapagos’ most iconic endemic species and the only sea-going lizard species in the world, are now the subject of one of the most innovative citizen science projects in the Islands. ‘Iguanas from Above’, led by our partners at Leipzig University since 2019, offers conservation enthusiasts (including you reading this blog!) the chance to directly support marine iguana conservation from the comfort of their own home by counting marine iguanas in drone footage.
There are several threats to marine iguana populations, including invasive predators, pollutants including plastic waste and toxins from oil spills, and loss of key food sources (algae) during El Niño years. However, it is difficult to collect data on marine iguanas with traditional field methods, due to the remote, rocky, and often inaccessible sites most colonies live in. Before the start of this project, there was no reliable data available for 9 of the 11 subspecies of marine iguanas, yet accurate data on marine iguana populations is essential for reassessing their IUCN Red List status, monitoring threats and changes in their numbers over time, and taking appropriate conservation actions.

Drones offer a non-invasive, time and cost-efficient solution for surveys, and have been a key method for our field team. Drone surveys are delivered with great skill from a boat, and our team are at the forefront of developing safe boat-based drone survey methods together with Galapagos National Park Rangers. To date, drones are proving to be an accurate method for surveying marine iguanas, combined with monumental support from dedicated citizen scientists around the world.
Using the platform Zooniverse, citizen scientists are currently helping to count marine iguanas around Genovesa, Pinta and Marchena islands, from drone footage captured during the field team’s expedition to Galapagos’ northern islands in December 2021. Each photo needs 30 classifications, so altogether we need nearly three quarters of a million to finish this round!
...it is difficult to collect data on marine iguanas with traditional field methods, due to the remote, rocky, and often inaccessible sites most colonies live in.

A recently published plastic pollution impacts risk assessment for Galapagos’ marine vertebrates, led by GCT and the University of Exeter, also found that marine iguanas are one of the species most at risk from severe injury or death from ingestion or entanglement in larger plastic debris. To further understand plastic risk to marine iguana subspecies, we have also integrated plastic pollution identification into the counting process on Zooniverse.
The field team are now prepping for their next expedition to the central and western islands in Galapagos in January 2023, which is the final data collection trip to complete the data set of all marine iguana subspecies. Eventually, our data will inform revised and accurate population estimates, as well as a better understanding of which colonies are most threatened by plastics arriving on ocean currents.

Iguanas from Above is kindly supported by the International Iguana Foundation.
Get involved
Anyone with a phone or laptop and an internet connection can help count iguanas. Head to the ‘Iguanas from Above’ page on Zooniverse, click on the ‘classify’ tab and, after a quick tutorial, you’re ready to go!
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