In a nice report over at Gizmodo (http://gizmodo.com/confused-sharks-keep-trying-to-eat-googles-undersea-dat-1621591475), Google are reported to have revealed they have had to go back and 'shark-proof' some of their undersea cable as the high speed fibre keeps being mistaken for lunch by sharks.
http://gizmodo.com/confused-sharks-keep-trying-to-eat-googles-undersea-dat-1621591475