Fatal collisions with ships have become a leading threat to whale survival. Ships strikes are on the rise, due to a combination of increasing coastal ship traffic, smaller crew size, bigger vessels and faster speeds. Deafening underwater noise levels also prevent whales from hearing approaching propellers:
- Between 20 and 35% of all whales found dead show cuts and blunt trauma consistent with a ship strike;
- Ship strikes are the largest known cause of death for the endangered North Atlantic right whale, particularly calves who have undeveloped diving capability. The risk of ship collision is now also the biggest threat facing the blue whale, the largest mammal on earth; and
- The vast majority of ship strikes are not reported. According to an agency database, 42 of 292 incidents were logged only because whale carcasses were pinned to the prow of ships entering harbor.