The University of Florida research suggests over-fishing and more cautious swimmers might be responsible for the decrease in aggressive encounters, although the total number of shark attacks worldwide increased from 61 during 2005 to 62 last year.
The number of fatalities remained stable at four, far below the 79 attacks and 11 fatalities recorded during 2000, said George Burgess, director of the International Shark Attack File at the Florida Museum of Natural History.
As in past years, Florida was the world's shark capital during 2006 with 23 attacks, Burgess said. That is slightly higher than the 19 cases reported during 2005, but it's considerably lower than the annual average of 33 occurring from 2000 and 2003.
Elsewhere in the world, Burgess tracked seven attacks in Australia, four in South Africa, three in Brazil, two in the Bahamas and one each in Fiji, Guam, Mexico, New Zealand, Puerto Rico, La Reunion, Spain and Tonga.