"The great thing about the Texarkana fall was that there were so many reports over such a wide area with so many photos and videos. I've started plotting them on a map," he said. Cropper has written about similar falls of fish in Australia and overseas. "It's a genuine mystery," he said. "Rains of fish have been recorded for hundreds of years, but there is still no clear evidence as to what causes the phenomenon, only theories. Some claim the fish are picked up in waterspouts from nearby lakes. Other suggest flocks of waterbirds throw up fish they have eaten in an effort to avoid the worst of the storm. "Both theories have been put forward to explain the Texarkana event, but I think more data is required, and hopefully the people of Texarkana can help me with that."