Don't you watch shark week on Discovery Channel??? They have it once a year in August... Many shows about sharks; guys fishing for sharks, biologists trying to study them and their behaviors to help understand where they go and how they feed... They have had some interesting studies where they are putting GPS on them and tracking them...
Some GPS only go for two weeks, some for more, like a year... This year they have put cameras on the top fin that release after a couple of days or a week, then sends out a signal for them to come pick it up and get a "sharks eye" view of where the shark is going and what's it's doing... They are learning alot about them...
There's a guy that's discovered that a strong magnetic field will repel a shark. He's done studies to prove it... He put some bloody meat behind a row of strong electro magnets, then when the sharks come straight for the smell of the meat, then turn away as soon as they get to the magnetic field... He also noticed that sharks can't swim in that long stringy algea that grows from the bottom up as it won't let any current flow -so the sharks can't get water flow through their gills to breathe... The sharks will suffocate if they go in the algea where there is no current...
So he combined the two theories and made some lengths of pvc pipe and attached the electro magnets to them. By splitting the pipe into two or three sections it acts/looks like the stringy algea, it has the same effect on keeping the sharks from going in there... So they plan to try to make these rows of pvc pipes with electro magnets to "rope off" swimming areas in Australia to keep the sharks from crossing the line and going to the beaches to attach people... It could save many lives... If it works, it will make a barrier that the sharks won't cross. It will keep the people safe without having to harm the sharks...
There was another show that tracked the sharks and explained why the attacks on humans were increasing in Hawaii. It proved that when the "booze cruise" boats would dump the extra food in the water before returning to shore was attracting the sharks... Free food for them that they don't have to hunt... So they banned the dinner cruise ships from dumping the food in the water so it doesn't attract the sharks... The sharks learn that that area is a food source and keep returning. So by not throwing the food in the water, it will help keep the sharks from returning... A shark can swim 5000 miles in a day...