Whales in the Southern Ocean face the twin threat of a shortage of food and a loss of hunting grounds because of global warming, a new report from WWF  warns.
WWF promotes the protection of whales and encourages people to sponsor or sponsor animals such as a whale or dolphin .
The rise in temperature predicted over the next 40 years will lead to a drop in winter sea-ice coverage of Antarctic waters of up to 30 per cent in some key whale areas.
Krill, the fundamental food which underpins the entire Southern Ocean ecosystem, thrives in the sea ice and any loss will reduce the amount of food available not only to whales but to fish, seals, seabirds and penguins as well.
As the ice retreats migratory whales, such as the Blue whale and the humpback, will have to travel hundreds of miles further south each year to find the foraging grounds crucial to their survival.
In its report the wildlife charity WWF says the plight of the whales underlined the need to take action and reduce the risk of catastrophic climate change, reports the Daily Telegraph.
WWF  commissioned new research from US scientists Cynthia Tynan and Joellen Russell who combined the projections of state-of-the-art climate models to look at the likely affects of a 2°C rise in temperature on the Antarctic ecosystem, and particularly whales.
Their report was released to coincide with the 60th annual meeting of the International Whaling Commission (IWC) in Santiago, Chile next week when whaling nations, particularly Japan, are expected to repeat a call for the 1986 moratorium on the commercial hunting of whales to be lifted.
In the report Ice breaker: Pushing the boundaries for whales, WWF calls for better protection of critical habitats for whales and for easing the pressure on whales unrelated to climate change, such as over fishing, pollution and ocean noise.
The report claims a predicted 2°C rise in global temperaures above pre-industrial levels by 2042 would have a massive impact on whales in the Southern Ocean. Whales which rely on the sea ice, such as the Antarctic minke would lose anything up to 30 per cent of its habitat within a whale's life span of about 40 years.
Both resident and migratory whales relied on krill - found in abundance in 'frontal zones' where water masses of different temperatures meet - to build up the reserves that sustain them throughout the year.
Migratory whales such as humpback (Megaptera novaeangliae) and Blue whale (Balaenoptera musculus) would have to travel about 600 miles farther south to reach the food-rich areas. Whales would need more energy for the longer migration journeys and it would reduce the length of the main feeding season.
The WWF report said there was still time to avert environmental catastrophe but it was critical that there was co-ordinated global action.