>>Interestingly, it’s only the newer cables that seem to have this problem; reports suggest that the sharks aren’t biting the older cables, which contain copper wires instead of fiber optics.

I suspect it isn't copper vs glass fiber, but the voltage/frequency of the power in conductors alongside - that power being needed to power undersea repeaters. Wires have resistance - and that resistance goes up with distance and amperage (but not with voltage) - so high voltage. If you want to convert that high voltage to something more usable by your repeaters, it needs to be alternating current (simple DC only creates a field when the power is started or stopped).

My guess: the combined frequency (think sound tone) and voltage (volume) is as irritating to sharks as a mosquito is to us when we're trying to go to sleep. The sharks are just shutting up the irritating noise - the way we all try to kill that mosquito.

I'm curious as to what's being done to make these power conductors less irritating to sharks. Maybe there is a solution, but it's cost phohibitive (we're talking thousands of miles of cable, after all).