Spurred by reports of the odorous whales, U.S. and Russian toxicologists began testing tissue samples of stinky whales in 2003.
They looked for traces of heavy metals and other harmful compounds, such as organochlorines and polyaromatic hydrocarbons, which are products of industrial processes.
The samples show a slew of more than a hundred volatile compounds, including hydrocarbons, sulfur and nitrogen compounds, and various odorants. Yet the results are still unclear and do not appear to implicate human activity, said Wendy Elliott, a program officer at the nonprofit WWF-International.
But she thinks that perhaps the whales' diet might provide a clue.
Strangely enough, hunters have found that the stomachs of stinky whales are packed with seaweed.
"We are not fully sure, but it is possible that a change in prey abundance due to climate change is forcing the whales to change their diet," Elliott said, "and this is causing certain biochemical reactions within them."
The IWC report hints at the same conclusion, stating that gray whales appear to have reached carrying capacity.
Simply put, there are either too many Eastern North Pacific gray whales competing for the same food supply, or the food supply is fast drying up.
Biotoxin at Play?
But the report adds that the stink could also be caused by an unidentified biotoxin.
Lorenzo Rojas Bracho is coordinator of the National Marine Mammal Program at Mexico's National Institute of Ecology.
He said the stink could not be due to the whales approaching carrying capacity, because in that scenario a large number of whales would be affected.
Instead, he said there could one agent that might be causing the stink, and another agent causing the numbness in people who eat the meat.
Rojas points to various compounds such as aldehydes and ketones in the whales.
The whales might be suffering from a metabolic disorder from feeding in certain locations near Russia that are awash in odiferous compounds.
It is probably a regional, ecosystem issue, he adds, noting that the stinky smell has also been reported in other mammals and birds of the region.
"Maybe certain bacteria, fungi, and biotoxins are the cause of the stinky whale. This could explain the numbing, and is a more plausible explanation," he said.
Rojas said scientists from U.S and Mexico are working on a project to check the chemical composition of the blowhole breath of free-swimming whales in the breeding lagoons of Mexico. After breeding there in the winter, the whales move north.
If researchers find the problem that is causing the whales to become stinky, these whales could possibly be worked into a revised aboriginal whaling management procedure, to be put in place by 2009.
At the recent IWC meeting in Anchorage, Alaska, the Russian government announced that it did not consider the stinky whales to count against the quota, adding the whales do not fulfill the aboriginal subsistence needs. At the same time, the government recognized it could not make that determination unilaterally.
Russian aboriginal hunters maintain that at least 10 percent of the whales they hunt turn out to be stinky.
The IWC also upheld a shared catch limit of 280 bowhead whales until 2012 for U.S. and Russia indigenous peoples, and renewed the quotas for gray whales.
(See related: "Whaling Commission Renews Most Aboriginal Hunting Quotas" [May 30, 2007].)
"We did not gain anything, since our cultural and nutritional needs for whales exists with or without the quotas," whaling captain Inankeuyas said.
"The international community recognized our right to hunt, use, and eat whales. We feel very fortunate."
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