The critically endangered western gray whale (Esrichtiius robustus) has won a small victory in its fight for survival: some oil exploration companies have decided to delay seismic testing off the coasts of Russia.

The move could help protect the rare species' breeding season: Just 120-130 western gray whales remain, with only 25-35 breeding females, according to the International Union for Conservation of Nature's Western Grey Whale Conservation Initiative. In Korea, western gray whales are known as "ghost whales" because they are so rare.

The western gray whale isn't a unique species; it’s just a regional population that’s the same species as the estimated 20,000 eastern gray whales swim the oceans between Alaska and California. But this population's isolation, slow migration patterns and tiny numbers have made it a conservation priority for many environmental organizations.

Until last week, Russia's Sakhalin Energy consortium -- comprised of Shell and Gazprom -- was poised to perform underwater seismic tests off Sakhalin Island in a move to find new oil fields for drilling. But scientists feared that the sounds of these tests -- right near the whales' only known feeding grounds -- would have disrupted the whales' breeding season, sending them fleeing from the area before they fed enough to nurse any newborn calves. New whales are essential to the long-term survival of the western gray whale.

This is a bit similar to the debate over the Navy's use of high-intensity sonar and its impact on whales and other sea mammals, but this time around scientists were able to present new evidence that the frequencies specific to these seismic tests would cause distress to the gray whales.

The decision to delay seismic testing until at least 2010 came at last week's 6th annual meeting of the Western Gray Whale Advisory Panel, which was actually formed by the IUCN at the request of Sakhalin Energy. But the whales may not be completely out of the woods: Several other gas groups -- including BP, Exxon and Rosneft -- did not participate in the talks, and still plan on performing seismic tests in the area this year.

Image: Gray whale, via Wikipedia