International Whaling Commission scientists have warned that a seismic survey in Russia's Far East could push a critically endangered population of whales closer to extinction.
"The committee is extremely concerned about the potential impact on western gray whales and strongly recommends that Rosneft postpone their survey until at least June 2011," the scientists said in a report released this week, referring to the Russian company carrying out the testing.
There are probably fewer than 130 Western North Pacific Gray Whales remaining, and only a couple of dozen females of calf-bearing age, according to the IWC.
"The Rosneft survey (is set to) occur while the highest number of feeding gray whales, including cow and calves, are present," the 120-strong committee cautioned.
IWC delegates from the United States, Mexico, Britain and other countries backed the delay.
But in a plenary session Wednesday a Russian negotiator indicated that the tests would likely go forward as planned.
Numerous studies have shown that noise pollution in the sea reduces the zone in which whales can feed, and hampers their ability to communicate.
Some forms of noise smog -- including from seismic surveys -- are so powerful that whales can be seriously injured outright by the shock, the International Union for the Conservation of Nature (IUCN) has reported.
Sonars used by the military and the oil industry can exceed 230 decibels in volume, and can be deadly within a one- or two-kilometer (0.6- or 1.2-mile) radius, according to Michel Andre, director of the Laboratory of Applied Bio-Acoustics in Barcelona.
The IWC scientists noted that another Russian company conducting seismic probes in the same region, Sakhalin Energy, has adopted IUCN recommendations in terms of timing and procedure to avoid harming the rare marine mammals.
"It's not as if the committee is asking them not to do the survey," said Wendy Elliott, species manager at WWF International.
"All they have to do is wait a year and conduct it earlier, before the whales arrive in the area."
Explore further: Study of bigeye tuna in Northwest Atlantic uses new tracking methods