After months of consultation and debate, the Vancouver Park Board has voted to approve a $90-million expansion of the aquarium in Stanley Park.

The area occupied by the aquarium will grow by 50 per cent, requiring the removal of 32 trees.

Monday night's vote on the project had been expected to be close, but only one park board commissioner voted against the plan.

Some people spoke out against the project at the public meeting, saying a bigger aquarium means more animals in captivity.

But aquarium president John Nightingale said the bigger pools are necessary to look after the animals.

"We've said whether we have the current facilities or the new ones, that eight dolphins and eight whales is an ideal family group. So it doesn't matter one whit whether it's the new facilities or the old ones, except that the new facilities will provide those animals with much better care."

The park board has imposed some conditions.

The aquarium must pay for the maintenance of the new plaza and a new salmon stream. It also has to donate 1,000 aquarium passes each year to community centres.

Nightingale hopes construction will start by the spring. It's expected to take four years.