The water levels in Norway's Tesse Lake recently receded and experts discovered four ancient fish traps installed 7000 years ago.

Ancient Fish Traps in Tesse Lake

A 7,000-year-old fish trap was discovered when a hiker observed a number of wooden poles dipped into the dry lakebed.

According to a Cultural History Museum press release dated September, Reidar Marstein, a climber and amateur archaeologist, discovered the old traps in Tesse Lake last summer. The trap became momentarily visible when the lake's waters decreased.

According to a press release, archaeologists did a preliminary examination of the site and assigned a 5000 BC age to one of the wooden planks that made up the trap. As the oldest fish traps in Norway and the oldest of its sort in northern Europe, these ruins date back to this time.

Sharpened wooden poles were inserted into the lakebed to create the fish traps. The traps were situated in shallow water and probably resembled lollipop shapes, according to the Cultural History Museum.

Archeological Secrets Hidden and Revealed by Water Levels

A wooden fence was used to direct fish into the center of the circular trap chamber. The according to the museum, once inside, fishermen of that time could bring in their harvest from a boat or by wading into the chilly water.

But before archaeologists could conduct last summer's excavations, the lake's rising water levels flooded the Stone Age traps.

According to the Cultural History Museum, the water levels in Tesse Lake, which is located approximately 180 miles northwest of Oslo, change seasonally. The lake is emptied in the early summer to generate electricity, then when the snow cover melts, it fills back up.

Undaunted, the archaeologists waited patiently for the water to dry up. According to the museum, the initial fish trap excavations started on June 4 and went on as long as the low water levels permitted.

Reverse Engineering an Ancient Fish Trap

Four fish traps have been discovered, and one has been entirely excavated, according to a June 21 statement from the museum. More than 50 remarkably well-preserved wooden poles were discovered.

The poles were hammered into the seafloor with considerable power, according to Axel Mjaerum, the archaeologist in charge of the dig. The tips of the pointy ends have a small amount of damage.

According to the museum, items that were buried between the trap's poles and tightened the chamber so that fish couldn't escape were also found.

Stone Age village remnants have previously been discovered during excavations at Tesse Lake, according to Science in Norway.

To hunt reindeer, Stone Age people traveled to the highlands. The Innlandet County Municipality's glacial archaeologists who worked on Secrets of the Ice have discovered several remnants of widespread reindeer hunting spanning many centuries. The age of the arrowheads increases with the age of the melting ice.

Mjaerum argues that fishing activities in the area may have also served as a steady source of sustenance, Yahoo News reports.