HALIFAX - The number of small spills reported by the energy companies that operate Canada's offshore oil and gas rigs has far exceeded their original predictions, a new study says.

Researchers at York University and the Alder Institute in Newfoundland found that the operators of the Terra Nova project off Newfoundland, for example, had originally predicted 5.3 spills of less than 50 barrels per spill during the 15-year lifespan of the project.

However, Terra Nova has had 34 spills of that size since development started in 1999 -- more than six times higher than Petro-Canada had anticipated in its environmental assessment.

John Downton, a spokesman for Petro-Canada in St. John's, N.L., said he couldn't comment on the study because the company needed more time to examine its methodology.

The study, published Monday in the Journal of Environmental Assessment, Policy and Management, also found that the Sable Offshore Energy Project off Nova Scotia reported 57 small spills by 2004 -- again, a rate more than six times higher than predicted.

As for the White Rose project off Newfoundland, it has had four spills of less than 50 barrels since development started in 2003, the study said.

That's almost double the number predicted for the project's 15-year lifespan, the study said.

About 30 barrels of crude spilled from the White Rose production vessel only last week.

Graham White, a spokesman for Calgary-based Husky Energy Corp., said the predictions hold the company to a high standard.

"The predictions are issued as best-case scenarios ... and that's something we are in agreement with," he said in an interview.

"If the idea is to get to best practices, it's something we strive for as a responsible operator. ... I don't think it's unreasonable for the regulator to ask for zero spills."

Prof. Gail Fraser, a bird biologist at York, said the study should provide a wake-up call to the two regulatory bodies that oversee the offshore energy industry in Atlantic Canada -- the Canada-Nova Scotia Offshore Petroleum Board and the Canada-Newfoundland and Labrador Offshore Petroleum Board.

"I'm not faulting the operators for going over their predictions," she said in an interview. "The board has not followed through on their job. ... They're not fulfilling their obligations under the Canadian Environmental Assessment Act."

Fraser said the environmental assessment predictions are worthless unless the boards -- responsible for environmental protection and enforcement of regulations -- do something with them.

"The boards haven't articulated that the predictions are not working for this region. It's their job," she said.

"Our goal is to move the management of this industry to best practices, and I don't think they're there yet."

Sean Kelly, a spokesman for the Newfoundland board, said officials were still reviewing the study Monday.

Fraser stressed that the environmental impact of small spills can be considerable.

Small amounts of oil and other drilling fluids can spread over a large area and researchers have long known that it takes only a few drops of oil or drilling fluid to foul the feathers of a seabird, leaving it with no chance to survive the cold waters of the Atlantic.

"There is no relationship between the size of the spill and the number of birds killed," Fraser said, citing prior research. "You can have very small spills that kill lots of birds."

Since 1997, the Newfoundland board has recorded 337 spills, which dumped an estimated 430,000 litres or 2,700 barrels of synthetic drilling fluids and other hydrocarbons into the ocean.

Those spills came from the Terra Nova, White Rose and Hibernia offshore developments, as well as exploratory drilling activities.

Fraser said the study did not include large spills because no predictions were made about such events, and the Hibernia project -- operated by ExxonMobil -- was not included because its development started before spill predictions were required.

Fraser said it's important to note there has been only one large spill from a rig on the East Coast.

In late July 2005, Petro-Canada was charged with spilling more than 1,000 barrels of crude from its Terra Nova production vessel.

While spill predictions are required under the 1995 Canadian Environmental Assessment Act, the study concedes these figure are "inherently uncertain."

The key is followup monitoring to determine the environmental impact of a project, the study says.