This project is part of an ongoing study of the invertebrates along the Róbalo watershed, which is located on Navarino Island in Chile and supplies drinking water to the world’s southernmost town, Puerto Williams. It is a part of the UNESCO Cape Horn Biosphere Reserve and spans the altitudinal gradient of the Dientes de Navarino mountain range. Areas at higher latitudes and altitudes are the most susceptible to temperatures changes related to global climate change. Because of the drastic changes in thermal gradient and plant community over a small change in altitude, this river serves as an excellent natural laboratory to study the impacts of a warming climate on flora and fauna. Larval and adult Chironomidae have been collected regularly since 2005 and a study of pupal exuviae was initiated in 2018 to assess their utility as a potential tool to measure community responses to environmental changes in the watershed. Although the results are preliminary, changes in taxa composition were observed along the gradient and a longer-term study will be initiated.