A group of Vancouver environmentalists is trying to stop the strange disappearance of bee populations, by creating new urban habitats for the insects.

Experts are still trying to determine the exact cause behind Colony Collapse Disorder (CCD), which was first given an official name in 2007. Every year, a third of Canadian bee colonies are lost.

The insects are crucial to our food supply -- bees are needed to pollinate most of our vegetable and fruit crops. The European honeybee provides up to $1 billion worth of pollination services to agriculture in Canada every year.

So why are bees disappearing? Theories point to pesticides, some sort of contagious virus, bacteria, or weakened immune systems. Other experts suggest the problem has more to do with a loss of habitat.

Responding to the latter idea, the Environmental Youth Alliance has set up 150 bee towers across Vancouver, with hopes that bees will use the homes to lay eggs. The project is also designed to raise awareness about the issue.

"We can create habitat by putting these things out," said spokesperson Hartley Rosen.

So far, the project is getting a lot of notice south of the border, where beekeepers have even gone to Washington to publicize their plight.

Some U.S. beekeepers are reporting losses of up to 95 per cent, and the U.S. Department of Agriculture has made CCD a central concern.

With a report by CTV's Rob Brown