Instructions: In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.
Input: 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." ||||| Image caption Catching fish is a practice that goes back thousands of years 
  
 Wooden fish traps said to be some 9,000 years old have been found in the Baltic Sea off Sweden, possibly the oldest such traps in existence. 
  
 Marine archaeologists from Stockholm's Sodertorn University found finger-thick hazel rods grouped on the sea bed. 
  
 They are thought to be the remains of stationary basket traps. 
  
 "This is the world's oldest find when it comes to fishing," said Johan Ronnby, a professor in marine archaeology. 
  
 Arne Sjostrom, a fellow archaeologist who worked on the Sodertorn project, said the sticks seemed to have been used as a "sort of fence to lead the fish into a creel or they were part of the actual creel". 
  
 The remains of seven basket traps were found in a submerged ancient river valley off Sweden's southern coast at a depth of 5-12m (16.5-40ft), Mr Sjostrom said. 
  
 Many examples of similar traps had been found in other parts of the world, he added. 
  
 Only one of the baskets has been carbon-dated and is estimated to be around 9,000 years old, the Associated Press news agency reports. 
  
 The 8th Millennium BC is believed to be the period when Stone Age man developed agriculture and built what were to become the world's first cities. |||||
Output:
Marine archaeologists have discovered fishing traps they think were constructed around 9,000 years ago. "This is the world's oldest find when it comes to fishing," says one expert. The researchers found the remnants of seven wooden traps on the Baltic Sea bed off Sweden, reports the BBC. The artifacts consist of sticks believed to once be components of basket traps. They may have been used as a "sort of fence to lead the fish into a creel or they were part of the actual creel," says one of the archaeologists. The pieces were discovered in an underwater ancient river valley near Sweden's southern coast, and carbon dating revealed one of the traps to be about 9,000 years old, notes AP.