Blue whales are the largest animals on the planet. An adult whale weighs hundreds of thousands of pounds - the weight of 30 elephants - and can be as long as three school buses.
But the majestic creatures are no match for the behemoth cargo ships speeding along the Northern California coast.
Since July, at least five whales have been killed by ships in local waters - the same number killed during the previous five years combined.
As a result, government agencies such as the U.S. Coast Guard are now considering changing the lanes and other ship traffic rules to keep the endangered mammals safe.
The Coast Guard is conducting a study to determine whether modifications to shipping lanes near San Francisco are necessary. Last year, a similar study prompted new regulations in shipping corridors along the Eastern Seaboard after a rise in the number of whale deaths from ship strikes.
The Coast Guard is soliciting public comments until Jan. 20 at www.regulations.gov; enter keyword "2009-0576."