Dolphins are threatened by many natural predators, but there biggest threat is man.
This is due to illegal dinamite fishing, dolphins getting caught in fishing nets, them colliding with boats or propellers, marine pollution and interference through sonar waves.
Research shows that over 95% of dolphin deaths are due to human actions.
Even holding them in aquariums or research facilities contributes to their death.
Their capturing, transportation and captivity all contribute to this death toll.