Blue whales are the largest animals on Earth, in fact the largest animals that have ever existed on Earth. If hitting a deer with a car is bad news, imagine the catastrophe that would be hitting a blue whale with a cargo ship. Well, that’s looking like a real possibility, according to a 15 year study by Oregon State University Researchers: They found that blue whales’ preferred feeding grounds are bisected by heavily used shipping lanes.

“The main areas that attract blue whales are highly productive, strong upwelling zones that produce large amounts of krill – which is pretty much all that they eat,” said Ladd Irvine, a researcher with OSU’s Marine Mammal Institute. “The whales have to maximize their food intake during the summer before they migrate south for the winter, typically starting in mid-October to mid-November.”

“It appears that two of their main foraging areas are coincidentally crossed by shipping lanes,” he added.

They found that a slight alteration of shipping lanes – at least when the migration begins – could significantly lower the chances of a whale-ship collision. A similar alteration in Canada’s Bay of Fundy lowered the risk of collisions with endangered right whales by a staggering 80 percent.

For the study, the researchers attached transmitters to 171 blue whales off California at different times between 1993 and 2008 and tracked their movements via satellite. Running for 15 years, it’s the longest study of its kind and has yielded mountains of important data regarding blue whale movements and habitats.

It’s believed that 25 percent of the world’s blue whale population spends time off the coast of California. The whales, which can weigh as much as 25 large elephants, have been known to travel from the Gulf of Alaska all the way down to an area near the equator known as the Costa Rica Dome.

Bruce Mate, who lead a series of tracking studies featured in the 2009 National Geographic documentary “Kingdom of the Blue Whale,” says relocating shipping routes is the best and perhaps only option.

“During one year, while we were filming the documentary, five blue whales were hit off of southern California during a seven-week period,” said Mate, who directs the Marine Mammal Institute at OSU’s Hatfield Marine Science Center in Newport, Ore. “Blue whales may not be as acoustically aware as species that rely on echolocation to find prey and there is some evidence that the location of the engines in the rear of the ship creates something of an acoustic shadow in front of them, making it hard for whales to hear the ship coming.”

He notes that making ships louder isn’t as effective a solution as it would seem, as it would likely just drive the already endangered whales from their preferred feeding locations.

The researchers hope their work will go on to help enact laws aimed at preserving the whales, noting that it’s rare for research to be so directly applicable to policy making.