Sharks are generally one of the top predators in any ocean. As a result, if they disappear the rest of the ecosystem tends to loose its balance.
The number of these predators facing global extinction has doubled in just 1 decade. A study recently found that shark and ray numbers are down 70% in the last 50 years. Species that were once pretty common like hammerhead sharks are now in danger of disappearing for ever.
These sorts of sights are already rare, however, we could see them consigned to history if dramatic action is not undertaken in the next few years.