Even in the middle of the morning, activity at the fishermen's guild of Blanes is frantic: a coming and going of boxes full of anchovies and sardines, and mullets and other fish, arriving at this Girona fish market for auction. Unaware of this hustle and bustle and sheltered under the piers, about forty individuals rest, impassive, in enormous water tanks. Some have been there for a short time and are recovering, waiting for their moment to come. Others are already prepared and will return to the sea soon.

Imagine a computer, an internet connection, and the desire to contribute to science. Now imagine all of this transforming into invaluable data that can be used to protect a unique animal species on the list of vulnerable species: the marine iguanas of the Galapagos Islands. This scenario is possible thanks to citizen science.