Just how much progress will be sharply debated this week when pro-whaling and pro-conservation countries square off in Santiago, Chile at the annual meet of the International Whaling Commission (IWC).
Despite the moratorium on commercial hunting of big whales, voted in 1986, Japan, Norway and Iceland continue to cull more than 2,000 each year, mainly minke, along with smaller numbers of humpback, fin and sei.
Anti-whaling nations and conservation groups reject calls for sustainable quotas, and say the ban should be kept in place -- and enforced.
Some species, all parties agree, are hovering on the edge of extinction.
The North Pacific and North Atlantic right whales -- two separate species -- along with the gray whale, have each been reduced to a few hundred survivors.
"Their situation is very critical. It could go either way," said Regina Asmutis-Silvia, senior biologist at the Whale and Dolphin Conservation Society, noting that stocks have not increased despite 70 years of protection.
But even species counted in the thousands and expanding each year by three, four or even eight percent are not out of danger, and would need decades of uninterrupted growth to regain their original numbers, scientists say.
Blue whales, which reach up to 25 meters (80 feet) in length and can weigh as much as a passenger jet, have recovered from a low of 400 specimens in the 1970s to some 2,200 today, says Jean-Benoit Charrassin, a marine biologist at the Natural History Museum in Paris and a delegate for France at the IWC.
"But that is only about one percent of their original stock," he said.
At least a quarter million blue whales swam in Antarctic waters until the start of the 19th century, when technology -- exploding harpoons, on-board processing -- nearly relegated them to museum displays.
The Antarctic humpback is doing better, with a population of about 50,000 -- 30 percent of its original size -- and annual growth rates of seven or eight percent.
But scientists and conservation groups remain implacably opposed to commercial hunts even for whale species that appear to be thriving.
There are "too many uncertainties about the statistics," said Charrassin.
A recent study, based on 2007 aerial surveys and led by Gisli Vikingsson of the Marine Research Institute in Iceland, reported a "significant decrease" since 2001 in the population of minke whales. Japan and Norway killed more than 1,600 minke in 2007.
Nor is commercial hunting the only threat.
"It is a mistake to factor out the single issue of hunting," said Asmutis-Silvia. "You need to look at the cumulative impact of vessel strikes, entanglements in fishing nets, pollution, destruction of habitat and acoustic disturbances."
Climate change is also looming as a danger. Acidification of the oceans, driven by global warming, could sharply reduce the number of krill, shrimp-like creatures that are the mainstay of the whale diet.
An adult blue whale can eat up to 40 million krill in a day.
And even if the tiny crustaceans resist acidification, whales are now competing with fish farms that scoop up krill by the tonne for feed.
For Yves Paccalet, a French naturalist and philosopher who helped push through the 1986 moratorium, the intelligent and highly-social creatures may be so exhausted from their centuries-long combat with humankind that they have simply have given up the fight.
"The psychological consequences of our aggression have compromised their will to live," said Paccalet, who worked extensively with French marine explorer Jacques-Yves Cousteau.
"To reproduce, whales need a large number of individuals to ensure that they meet, and then to frolic and excite each other. Otherwise, a species may give in to a kind of sexual melancholy and simply stops breeding," he told AFP.
The giant blue whales are so few, he added, that they rarely cross paths.
"The balance remains very fragile: if we leave whales alone, it is not impossible that they will prosper. If we don't, the decline could be rapid," he said.
June 22 2008
Source: PhysOrg.com