KEY POINTS:
When two anorexic creatures appeared from over the horizon in the waters of Laguna San Ignacio, off Mexico's Baja California last January, William Megill was quick to identify them.
"We have Kate Moss and we have Twiggy," said Dr Megill, with a wry smile, of the female grey whales he saw struggling down the coast as he was speeding around in the University of Bath's research vessel.
"The ribs on one were quite visible, while the vertebrae on another poked out where there should have been inches of plump and healthy blubber," Dr Megill said. They were, he speculated, possible further evidence of the unforeseen impact of climate change on one of the world's most mysterious creatures.
"These were hungry whales which have probably endured two seasons without enough food," he said. "When they lose fat they lose insulation and start to feel cold and eventually die, literally starved to death."
Scientists who study the world's remaining grey whales see them for only a few seconds at a time when they surface for air. They photograph and catalogue every sighting and provide sometimes whimsical names. These whales were so hungry-looking that they were instantly named Kate and Twiggy.
Off San Simeon, California, recently, biologist Wayne Perryman pointed to a female grey whale making her way laboriously up the coast, a shoulder blade protruding through in a bony ridge. "That female looks a little skinny," he told the reporter from the Los Angeles Times. "You can see her scapula sticking out. Yeah, she's a skinny girl."
The phenomenon of skinny whales was first noticed earlier this year in the shallow San Ignacio Lagoon, where they over-winter while giving birth and then nurse their calves before setting out on their 9600km journey back to once-rich feeding grounds of the Bering Sea. It was in San Ignacio that a group of young American marine biologists noticed the telltale signs of malnutrition.
The skinny whales had arrived in Mexico after swimming from the Arctic Ocean. It is one of the world's most extraordinary environments, a place of wild untamed seas and thousands of kilometres of ice, that forms an ecosystem few people know exists, and fewer still understand. But as the ice cap melts something dramatic has happened to the Arctic food supply.
Another, equally dramatic change is taking place. Climate change is providing, for some, a opportunity for a rapid economic development in areas previously beyond reach. The US Government is moving to open up some 33.5 million hectares of Alaska's seas for oil and gas development. Two of the areas already in the sights of BP, Shell and Conoco Phillips are the Chukchi and Beaufort Seas - both relatively unknown, except to the grey whales, which feed there every summer.
The stakes are high for all concerned. For while climate change is seen as a dire threat to the planet, for a US increasingly concerned about security of oil supplies, it is a potential bonanza. Reduced polar sea ice is expected to open up the Northwest passage through the Arctic Ocean, turning it into a oil tanker route for parts of the year.
At the same time the US, Canada and Russia are moving to develop newly accessible oil and gas fields. The plans for oil and gas development are expected to spread across Alaska's seas from the Canadian border to the border with Russia. A new plan to begin offshore production of oil and gas in the area the grey whales feed is expected to go into law in the next couple of weeks, if Congress does not object. Because high petrol prices are hurting so many Americans, it would be political suicide to stop it.
The grey whale is one of the greatest symbols of humanity's capacity to wreak environmental havoc. It was hunted to extinction in the Atlantic by British, American and other whalers in the last century. It had almost died off in the Pacific as well when the hunting ban was imposed. These days only 140 are taken every year by Russian hunters and the population has recovered to the extent that 17,000 whales migrate each year between the Arctic Circle and Mexico as well as down the eastern seaboard of the Pacific ocean.
Unexpectedly, hunger has suddenly become a mortal threat to the survival of the grey whale as well as other animals which feed in the Arctic circle.
"The basic problem," says Dr Megill, "is that there isn't enough for them to eat in the Arctic Circle in the summertime, so they've been arriving hungry on the breeding grounds, and since there really isn't much for them to eat in Mexico, they've left the breeding grounds even hungrier, and now look emaciated as they make their way north."
Something unexplained has cut off much of the whales' food supply in the Arctic Circle, where the ice is retreating.
For millennia the Pacific grey whales have gathered every summer to feed in the shallow waters of the Chirikov Basin, in the north Bering Sea. The area was a vast conveyor belt of crustaceans called amphipods which the whales sucked in through their filtering system of baleen, building up blubber before heading back to Baja California..
"You could practically walk across the grey whales in the Chirikov Basin in the 1980s," said Sue Moore, a scientist who has conducted aerial surveys of the area. "They were stacked up to the horizon. In 2002, I went back and everything had changed."
One theory is that global warming means there is less ice, and the algae mat which usually grows on the bottom of the ice in the spring is no longer there. These amphipods grow on muddy seafloors and rely on bits of algae to feed on. If there is no algae they die.
Whales have died in large numbers before. During the last big El Nino in 1997-99 hundreds, if not thousands, starved to death.
Dr Megill, whose research is funded by the Earthwatch Institute, is reluctant to blame global warming alone for the grey whale crisis. But he warns that if further research this northern summer reveals that whales have nothing to eat in the Pacific northwest, "then it is really time to start screaming about the impact of global warming".
If and when the grey whales start dying in large numbers, "there is not a lot we can do to rescue the situation", Dr Megill says. "It will be another sign of the possibly irreversible damage being done to the Pacific Ocean."
The Northern Bering and Chukchi Seas are among the most abundant marine ecosystems in the world. The northernmost tip of the Bering Strait leads to the Chukchi Sea, which lies between the Chukotka Peninsula of Russia and Alaska's northwestern coast. A shallow ocean shelf runs underneath the two seas all the way to the Beaufort Sea on the Canadian border. On the Russian side is the World Heritage site of Wrangel Island, famous for its nesting birds, polar bears and walrus breeding grounds.
It is incredibly fertile because a combination of long summer days, cold weather, ocean currents, and nutrients welling up from the sea produce huge algae blooms, which provide the base of the food web of the whales and other mammals. The seas are also shallow, so algae reaches creatures living on the ocean floor. Or used to.
The icy waters also kept away prey fish such as salmon that would eat the algae and plankton before it reached the seafloor. That meant more food for the grey whales, walrus, and deep-diving sea ducks. These nutritious waters contribute to healthy oceans and a stable global climate by stabilising the weather patterns.
But scientists are increasingly recognising the importance of the Arctic Ocean's sea ice as they study the effects of climate change. The ice keeps water temperatures constant and keeps the planet cool by reflecting the sun's rays. The algae and phytoplankton that bloom on the edge of the sea ice keep whales, walrus, and polar bears alive.
Migrating birds also live on the ice edge. The bar-tailed godwit, flies non-stop to New Zealand for winter - a 10,900km trip.
Many more mammals depend on the sea ice. Its retreat may be jeopardising the future of seals, walrus, grey and other whales, and the polar bear. Two years ago, several baby walrus were found floating off the Chukchi Sea and were doomed to starve. Seal pups have been found emaciated, or dead because their lairs built in snow melted before the pups were weaned. And now the grey whales are showing up hungry off Mexico.
"I hesitate to get too alarmist," says Dr Megill, "but this summer will tell a lot about the future of our planet."
- INDEPENDENT
