Sept. 11, 2007 — One of the great success stories of the ocean, the return of the Pacific gray whale, may have been based on a miscalculation, scientists reported Monday in a study based on whale genetics.
What was assumed to be a thriving whale population actually is at times starving from a dwindling food supply, said study co-author Stephen Palumbi, a Stanford University marine sciences professor. And global warming is a chief suspect.
Scientists may have underestimated the historical number of gray whales from Mexico to Alaska, according to the study published Monday in the Proceedings of the National Academy of Sciences . And that may have led to a misdiagnosis of what is behind surprising die-offs over the past few years and the appearance of many so-called "skinny" whales.
Earlier this month the National Marine Fisheries Service reported that at least 10 percent of gray whales returning to one of their four main calving and breeding lagoons off Baja California showed signs of being underfed. Some of the whales even had bony shoulderblades.
"This is a hint of a problem," Palumbi said. "Our antennas should be up. Our antennas should be asking if the ocean is capable of supporting life the way it used to."
A rare sturgeon is key to a vital breeding program.
Get more Discovery News video here.
The study concludes that the original Pacific gray whale population hundreds of years ago may have been far higher than currently thought — closer to 100,000 whales than conventional estimates of 20,000 to 30,000.
The scientists base that on how diverse the population of whales once was — information they gleaned by examining differences in the DNA of 40 whales. They studied 10 spots on the whale's genetic blueprint.
