7,000 years ago, humans carried trout past waterfalls into mountain lakes

Ancient hunter-gatherers carried live brown trout past steep waterfalls to stock empty mountain lakes in Norway 7,000 years ago, creating managed fisheries whose descendants are still being caught by local anglers today.Archaeologists at the University of Oslo discovered well-preserved wooden fish traps at Lake Tesse, a mountain lake located 850 metres above sea level in southern Norway. Radiocarbon dating, published in the journal Antiquity, confirmed that these carefully built traps were used from around 5000 BC onward.The discovery shows that Mesolithic hunter-fisher-gatherers deliberately changed high-altitude ecosystems to create reliable food supplies centuries before farming reached Scandinavia.Filling an empty landscape with life Until around 8400 BC, the Fennoscandian ice sheet covered Lake Tesse beneath kilometres of thick ice. When the glaciers melted, they left behind a fresh landscape.People began moving into the southern highlands around 8000 BC, but the newly formed lakes contained no fish.