Extant animals size

[Catherine]

Sharks are an ancient form of life and they have survived many things like the extinction of the dinosaurs. They must be perfectly adapted to their environment to have lasted unchanged for so long. They also must be essential to the well being of the oceans.
The oceans as we know them and as the dinosaurs knew them and even earlier have never been without sharks. We should think very carefully about how we treat sharks and how we are endangering their existence.  I don't think we really want to find out what the world would be like without sharks.