Lonely whales are 'losing the will to live' due to over hunting

The psychological impact of over-hunting on the highly intelligent and sociable animals has been identified as the latest threat to the survival of the species.

The whale population has already fallen dramatically over the past few centuries because to culling by Japan, Norway and Iceland, and the poisoning of oceans which kills off their food.

Whales could be extinct within decades

But now a French scientist has said the majestic mammals - which can reach 80ft in length and weigh the same as a passenger jet - could also suffer from heartbreak.

Paris naturalist Yves Paccalet said: 'It may be that these intelligent animals are so exhausted from their combat with humankind that they have simply have given up the fight.

'And the psychological consequences of our aggression have compromised their will to live.'

Paccalet, who worked with French marine explorer Jacques-Yves Cousteau, added: 'To reproduce, whales need a large number of individuals to ensure that they meet, frolic and excite each other.  

'Otherwise, the species may give in to a kind of sexual melancholy and simply stop breeding.'

Despite an international moratorium on whale hunting in 1986, Japan, Norway and Iceland continue to cull more than 2,000 a year for their meat and oil.

Some species like the North Pacific and North Atlantic whales have been reduced to just a few hundred survivors, and could be extinct within decades.

Over hunting is causing social problems which mean whales could stop breeding

Even species counted in the thousands and expanding each year by up to ten per cent would need many years of uninterrupted breeding to regain their original numbers, scientists say.

Blue whales have recovered from a low of 400 in the 1970s to around 2,200 today, but that is believed to be  only  one per cent of their numbers 500 years ago.

A 2007 study by the Iceland Marine Research Institute revealed a 'significant decrease' in the population of minke whales since 2001. Japan and Norway killed more than 1,600 minke in 2007.

Regina Asmutis-Silvia, senior biologist at the Whale and Dolphin Conservation Society, said commercial hunting was not the only threat to their survival.

'It is a mistake to factor out the single issue of hunting. You need to look at the cumulative impact of vessel strikes, entanglements in fishing nets, pollution, destruction of habitat and acoustic disturbances.

'Climate change is also looming as a danger, and acidification of the oceans driven by global warming could also sharply reduce the number of krill, which are the mainstay of the whale diet.

'Their situation is very critical. It could go either way," she said.

Respresentatives from pro-whaling and pro-conservation groups will come face to face at the International Whaling Commission's annual meeting this week to discuss how to save the species from extinction.