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What's Killing the Whales?

A whale washes ashore in San Francisco Bay, then a second whale, then a third. The deaths continue, though no one seems to know their cause. Within weeks the number exceeds ten. At that point CNN arrives and broadcasts the story worldwide. "Puzzling deaths," the network calls them, and justifiably so. With no harpoon marks or signs of starvation, the dead whales have researchers stumped.

Now, more than a month later, the mystery remains. Preliminary tests on tissue samples taken from the dead whales have offered little new information. Meanwhile, more whales have washed ashore. Unlike a typical year, in which anywhere from nine to twenty Gray Whales are found dead on the California coast, in just the first few months of this year the number has already reached thirty-nine.

Once among the world's most endangered species, Gray Whales have rebounded in recent decades. It's estimated that some 26,000 currently exist in the waters off the western coasts of North and South America. It's possible, therefore, that the recent jump in whale deaths is the result of overpopulation. With more Gray Whales sharing the same waters, there's greater competition for food.

Yet the animals that have washed ashore don't appear to be malnourished. Perhaps it's a virus, then, that's responsible. Or it could be an infection. Or a pollutant. Or interference from boats.

Complicating matters is the fact that Gray Whales have the longest migration route of any mammal, spending summers in the Arctic and winters near Baja California. The distance between these points is 5,000 miles, and only some stretches are accessible to researchers or easily monitored.

For that reason the public is encouraged to help investigative efforts by reporting Gray Whale sightings to the Marine Mammal Center in Northern California. Reports should include the whale's location, size, and condition, plus the time that the observation was made. The Marine Mammal Center's phone number is (415) 289-7325.

 

 

 

 

 

2007 eNature.com