A honeybee gathers pollen from a flower in Erie, Colo., in October 2008. A study in the journal Current Biology suggests honeybee populations are not in decline but that the need for the pollinators has grown in the last 50 years. ((Peter M. Fredin/Associated Press))

A new study suggests the number of domesticated honeybee colonies is on the rise globally despite a collapse in recent years across North America and Europe that heightened worries honeybee populations are in danger around the world.

The real issue facing the bees, say University of Calgary professor Lawrence Harder and Argentine researcher Marcelo Aizen, is not the honeybee numbers but the increasing work expected of them.

Aizen and Harder, writing in Friday's issue of the journal Current Biology, say honeybees are increasingly being used to handle pollination of crops, particularly high-value crops such as raspberries, cherries, mangos and almonds.

This added demand represents an economic issue and not a biological one, they say, though expansion of bee-dependent crops could put an environmental strain on those regions.

"The honey bee decline observed in the USA and in other European countries, including Great Britain, which has been attributed in part to parasitic mites and more recently to colony collapse disorder, could be misguiding us to think that this is a global phenomenon," said Aizen of Universidad Nacional del Comahue in Argentina.

"We found here that is not the case."

The two researchers looked at data from the Food and Agriculture Organization (FAO) and discovered that, since 1961, the number of managed honey-bee hives has increased by about 45 per cent. They say this growth in hives corresponds to rising production of honey but that at the same time, the amount of agriculture requiring animal pollination has risen more dramatically.

Agricultural production requiring pollinators such as honeybees made up 6.1 per cent of all agricultural production in 2006, compared to 3.6 per cent in 1961.

The researchers say this shift was driven by economic forces, as insect-pollinated fruit and nuts are often high-value crops.

This shift comes with its own environmental cost, they say, as the cultivation of high-value crops often displaces natural habitat, while honeybees themselves are often an invasive species when introduced.

"Such environmental costs warrant recognition and consideration during the development of agricultural and conservation policies," they wrote.

Rob Currie, a honeybee expert not involved in the research, said few dispute that demand for pollinators is increasing more rapidly than the honeybees can meet the demand, and said Canada's bee population has remained relatively stable.

But he said the study understates the health issues plaguing bee colonies.

"Honeybees are on a global basis experiencing far more serious problems than they have in the past, and a lot of that is related to this parasitic mite and the inability to control it effectively," said Currie, an associate professor of entomology at the University of Manitoba in Winnipeg.

"We're having trouble maintaining what we've got, and on top of that, the demand is increasing, so to downplay the idea that there is a serious concern there is not something I would agree with," he said.