The human success story is fast becoming a major catastrophe for other species, according to a new report by conservationists.

While the human population increases, the number of animal, bird and fish species have plummeted by almost a third since 1970.

Pollution, farming, urban expansion, over-fishing and hunting are being blamed.

Particularly badly hit are marine species, including the swordfish, which plummeted by 28 per cent in ten years between 1995 and 2005, while ocean birds have seen numbers fall by 30 per cent since the mid 1990s.

James Leape, WWF director general, said: "Reduced biodiversity means millions of people face a future where food supplies are more vulnerable to pests and disease and where water is in irregular or short supply.

"No one can escape the impact of biodiversity loss because reduced global diversity translates quite clearly into fewer new medicines, greater vulnerability to natural disasters and greater effects from global warming."

Biodiversity Minister Joan Ruddock said: "The fact that human activities have caused more rapid changes in biodiversity in the last 50 years than at any other time in human history should concern us all.

"Supporting wildlife is critical to all our futures and the UK will continue to give strong support to international action."

The report by conservation charity WWF comes ahead of the UN Convention on Biological Diversity next week, which will discuss aims to achieve a "significant reduction" in the current rate of biodiversity loss by 2010.

The pledge was made by the world's nations in 2002 "as a contribution to poverty alleviation and to the benefit of all life on Earth".

Today's report said that despite the declines appearing to flatten off in recent years, it is "very unlikely" governments will meet the 2010 target.

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