I thought the reason for more shark attacks was more seals since their population rebounded and so the predator that hunts them rebounds as well. A quick Google also blames global warming, more time for beaches with increased human population, and the seals were for Africa. I thought I remember something about Florida as well but all stories are about global warming since that is the new buzz word. Final note shark attacks have not doubled they have actually gone down, 2015 was a record setting high year. 2014 had 72 and 2015 had 98. If someone could get the number on attacks for 2016 it could help, all I could find are stories saying we are on pace for less then last year (2015).