The little-known Atlantic weasel shark only occurs in West Africa, an area which is most acutely threatened by illegal and unregulated overfishing. In 2015, we found a previously unknown aggregation of weasel sharks in the remote island nation of Cabo Verde, which could be the last stronghold of this rare and enigmatic species. We will launch a second expedition in 2016 to study the species’ biology, threatened status and potential tools for its protection.