Save The Sharks (Focus - May 10) points out that humans pose a much greater threat to sharks than they to us. Millions of sharks die every year in nets, as fishing by-catch and through the horrific practice of "finning," whereby sharks are caught, their fins severed to be served in shark-fin soup. They are then thrown back into the water to drown.
But a scientist at the Virginia Institute of Marine Science is quoted as saying that humans are more likely to be killed by lightning than sharks.
That statistic is true if we compare overall fatalities from the two causes. But your risk of shark attack changes immediately when you enter the water. The ocean is not a swimming pool. Many of the big animals there are curious and carnivorous. Sharks don't target people. They eat fish, rays, turtles, crustaceans and other things. But they investigate things they don't recognize the only way they can: with their mouths.
By far the most common factor in shark attacks is mistaken identity. They take an exploratory bite of something they encounter in murky, turbulent coastal water (sometimes a swimmer) or something that looks a lot like a seal on the surface (sometimes a surfer).
The risk is low, but never zero. When we enter the sharks' domain, we're visitors and we're no longer at the top of the food pyramid.