A group of Swedish marine archeologists say they have found what they believe could be the world's oldest stationary fishing traps on the bottom of the Baltic Sea, with the most ancient dating back at least 9,000 years.

Arne Sjostrom, an archeologist at Sodertorn University outside of Stockholm, says the remains of the seven basket traps, made out of hazel rods fastened together, have been found in a submerged ancient river valley off Sweden's southern coast at a depth of 5-12 meters (16.5-40 feet).

Only one of the baskets has been carbon dated, and is estimated to be around 9,000 years old. Sjostrom on Tuesday said his team is "pretty confident this is the world's oldest stationary fishing trap that has been found so far."