16,000 years’ worth of stories to uncover from sediment in a West Cork lake

In search of Ireland's ancient past by recovering and examining sedimentary ancient DNA (sedaDNA)

Robin Lewando and Dr Michelle McKeown (University College Cork), Dr Aaron Potito (University of Galway), and Dr Andrew Tighe (University College Dublin) collecting the sediment core at Three Lakes, County Cork. Pictures: Sarah Jane Power (University College Dublin) and Cathal Gannon (University College Cork)

If I told you that one of Ireland’s most remarkable libraries has no bookshelves, no reading room and no librarians — only mud — you might think I’d lost the plot. Yet deep in the sediments of a quiet lake in West Cork lies thousands of years of environmental change, written not in ink but in the sediment layers. Stay with me.

Three Lakes, tucked between Dunmanway and Drimoleague, may look unassuming at first glance, but beneath its calm surface rests an extraordinary archive: a long, continuous record of everything that has lived, died, grown, shed, bloomed, swum, or decomposed in the catchment since the last ice age. And thanks to advances in ancient environmental DNA, we can now begin to read this archive in ways that were impossible even a decade ago.