text: Did you read the article?  If you did, perhaps you missed the following statement quoted from the article:
  
  “A tsunami 300 years ago, or even just 60 years ago, would not have created as much marine debris that became a vehicle for moving species across the Pacific Ocean that could become invasive,” Chan said. “What makes these major tsunami-driven events different in modern times is the substantial human industrial infrastructure that we have built along the Pacific coast.”