Well, back in time they were so many sharks now they may become extinct.Why, well us humans are killing sharks by cutting of thier fins and making soup out of it and we just trow sharks back in the water to die.Another reason is because we just go shark hunting for fun. But soon we will probably all realise shark are help ful in many ways. One way is when sharks die we use thier cartalige (bones) to help burns and to sloe down the groth of tumors. One day they will be extint so the shark population is droping down fast. But we can stop it if you don't kill sharks.