Whales, gas and climate: a grey tale

Grey whales are confusing animals. Go back just three years, and the accepted wisdom was that there were two populations in existence.

The larger one lived on the eastern side of the Pacific Ocean with an annual migration route down the west coast of North America. A much smaller one dwelled in the western Pacific, off the eastern coast of Russia, migrating south as far as Korea and China.

While the eastern population has regrown after the commercial whaling era to a healthy 20,000+ individuals, the western grey whale is among the world’s most endangered cetacean populations, numbering about 150 animals. 

Will it follow the population that used to live in the Atlantic Ocean into extinction? If the answer to that question was unclear three years back, it’s now as murky as the seafloor sediments in which grey whales feed.

Two years ago, aiming to track western grey whales from their summer feeding grounds off Russia’s Sakhalin Island to their unknown winter breeding places further south, researchers tagged a male that they dubbed Flex. To their surprise, it headed not south but northeast – eventually ending up among the much larger eastern population.

At last year’s International Whaling Commission (IWC) meeting, scientists revealed they’d used photos to identify a total of 10 greys that spent time on both sides of the Pacific; and this year, we’re up to 14.

That might seem a small number; but it’s 10 percent of the population, so significant. Yet genetic studies indicate the two populations are pretty much distinct. You might ask why this matters; aren’t the habits of grey whales just a scientific curiosity? Well – no. It has clear ramifications in at least three areas.

One concerns oil and gas exploration. The western grey whale feeding grounds close to Sakhalin are also the location of a major gas field. The company Sakhalin Energy already has two platforms close to shore in Piltun Bay, whose shallow waters are especially used by calves. A third Piltun platform is mooted, while another company, Exxon Neftegas, has begun work on a facility further offshore near a feeding area used by adults. There’s documentary evidence – some of it obtained through research activities funded by Sakhalin Energy under the Western Grey Whale Advisory Panel – that seismic exploration and platform construction both disturb the whales.

The second implication concerns the application by the Makah, a Native American people living on the West Coast of the US, to hunt greys under IWC rules on aboriginal subsistence whaling. It’s already a controversial application for a number of reasons.

But if there’s a chance the Makah might take one of the few western grey whales that have strayed to the other side of the ocean that will be seen by some governments as another reason why the request should be turned down.

The third reason is that grey whales, like many other cetacean species, are already being affected by pollutants in the sea – the so-called “stinky whale” phenomenon – and are likely to be further compromised by climate change, as it alters the seasonal patterns of sea ice growth and retreat and the food supply. One grey unexpectedly went “walkabout” in the Atlantic and Mediterranean a couple of years ago, with the suspicion being that it navigated the Northwest Passage.

In order to project what these changes will mean for grey whales, it’s vital to understand where they currently go – and ideally, why. Further sighting and tagging projects are planned. They may yet write the natural history of grey whales in black and white.Richard Black