Ancient Norwegians Stocked Lakes with Trout 7,000 Years Ago

Hunter-gatherers in Norway intentionally introduced brown trout to mountain lakes at least 7,000 years ago, establishing a food source during seasonal foraging trips. Researchers at the University of Oslo determined this after studying well-preserved fish traps discovered in Lake Tesse, dating back to 4950 BC. The traps, maintained for centuries, prove humans actively managed the environment for sustenance long before farming arrived in Scandinavia.

The team ruled out natural dispersal due to the lakes’ isolation and geographical barriers like waterfalls. Evidence suggests people likely transported the fish using containers like waterskins and sustained longer stays in the mountains by combining reindeer hunting with fishing.

This discovery marks the oldest documented instance of human-mediated fish translocation globally. Further research may reveal details about the methods used to transport the fish and the broader impact of this early environmental management on Scandinavian communities.