Marine mammals or cetaceans may be adversely affected by human activities including underwater noise and ship strikes. One such activity, ship strikes of cetaceans, is a growing concern with the increasing number, size, and speed of ships. Ship strikes can cause cuts; propeller gashes or severed tailstocks; fractured skulls, jaws, and vertebrae; or haemorrhaging, massive bruising or other injuries noted during a necropsy of an animal. They also can cause damage to the ship involved. The International Maritime Organization in July 2009 adopted a guidance document to assist Member States and others prevent and minimize ship strikes. The North Atlantic right whale is particularly susceptible to ship strikes and ship strikes which are the largest cause of human-related mortality of this highly endangered species. Measures have been taken to reduce the risk of ship strikes of the right whale.

Additional reference information: 

• Office of Protected Resources page on Marine Mammals (NMFS, NOAA Fisheries)
• Alaska Fisheries Science Center, National Marine Mammal Laboratory (NMFS, NOAA Fisheries)