Making Whale Waste Count
HOBART, Australia, February 4, 2002 (ENS) - Japan's long disputed claim that it has to kill whales in order to study them is about to be further contested with a breakthrough by Australian scientists.
They have developed a method to examine whale stomach contents for the first time by DNA testing, sifting through the giant mammals' bodily wastes for their evidence.
Data collected tells the scientists what prey the whales consumed, gives an individual signature for each animal, and even shows which intestinal parasites they carry.
"We will be telling the International Whaling Commission (IWC) that this is a robust, non-lethal method for studying whales," said Nick Gales, a principal research scientist at the Australian Environment Department's Antarctic Division.
Despite repeated votes against Japan's whaling program at the IWC, its whalers kill more than 500 minke whales each year under self-awarded scientific permits. In 2000 Japan also began catching small numbers of the larger Brydes and sperm whales. The meat is sold at Japanese fish markets.
IWC permits demand consideration of whether scientists' questions can be answered using non-lethal methods, and Japan has repeatedly argued that it must kill whales to examine their stomach contents.
Gales said the DNA method, tested with blue whales, had found it was possible to identify in their feces prey species such as krill, as well as nematode parasites, and even the whales' gender and individual identity.
"It's going to provide some real information to put into food web models," he said. "If it points out that they are competing with fish stocks, then we'll have to deal with that," he said.
He agreed that some other Japanese research questions, such as fetal growth rates, could not be answered by the new method, which is yet to be tested with minke whales.
The breakthrough was achieved when individual researchers in Victoria, Western Australia, and the United States collected blue whale feces in nets. The wastes are eliminated by the animals near the surface, as a thin brown cloud in the water.
Using a technique first developed to examine bacterial assemblages in soil, Dr. Gales said the DNA contained in the wastes had been separated and individually identified, to be matched with known species.
He said collecting data could be time consuming, because it meant finding and staying close to surfacing whales. "But it's certainly no more time consuming than killing whales," he said. "And it's a lot cheaper."
Published in cooperation with the Antarctican, online at: http://www.antarctican.com