Whales once numbered in hundreds of thousands

BY KENNETH R. WEISS
Los Angeles Times
Aug. 02/03

   Before they were harpooned, sliced up and boiled for lamp oil, whales were far more plentiful in the North Atlantic than previously thought, according to new genetic analysis that could thwart any attempt to resume commercial whaling for a half-century or more.
   For years, scientists have worked to determine what the population of whales was before the onslaught of commercial whaling. The population figures matter because a ban on commercial whaling that began in 1986 will remain in effect until whale populations rebound to more than half of those pre-hunting levels.
   Despite being as big as a bus, whales are difficult to count. They are scattered over wide areas of all the oceans. They swim great distances to feed and breed, and are hard to track as they dive below the water's surface.
   Until now, the best evidence for calculating historic whale populations came from painstaking efforts to sift through the logbooks of old whaling ships.
   The new study, published in Friday's issue of the journal Science, is the first time scientists have applied sophisticated genetic tools to determine how many whales once roamed the oceans.
   Looking at telltale genetic variations that increase with population size, Stanford geneticist Stephen R. Palumbi and his former graduate student Joe Roman at Harvard determined that 240,000 humpback, 360,000 fin and 265,000 minke whales roamed the North Atlantic.
   By contrast, there are now about 10,000 humpback, 56,000 fin and 149,000 minke whales in the North Atlantic, researchers said.
   The estimates from the genetic study are much higher than those derived from the logbooks. That already has stirred a debate among scientists affiliated with the International Whaling Commission, which tries to manage whaling. The commission's regulations are based on the lower estimates of historic populations derived by the logbook method.
    Under the commission's rules, the current "pause" on commercial whaling would remain in effect until certain types of whales reach 54 percent of their pre-exploited populations.
   "Everyone knows that whales have been decimated, and there's an attempt to bring their populations back," Mr. Palumbi. "The question is, `Bring them back to what?'"
   "If you believe the logbook numbers, then the populations of some whales will be up to exploitable levels before the next presidential election," he said. "If these genetic numbers are correct, we are far from succeeding at bringing them back close to the status of what they were in the past. It will take another 50 or 100 years of protection."
   Mr. Palumbi's study is the latest in a series of scientific reports that indicate marine life was far more abundant before widespread human hunting than realized by present-day scientists.
   "We're were surprised at the genetic diversity," Mr. Roman said. The variations in genetic sequences, he said, were far too high to be supported the pre-whaling population estimates based on ship logs.
   "Whaling logbooks provide clues, but may be incomplete, intentionally underreported, or fail to consider whales that were struck and lost," Mr. Roman and Mr. Palumbi wrote.

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