Incidents posted online by the federal-provincial regulator suggest there were 39 leaks in 2011 of various oils and synthetic-based mud, a dense fluid used for drilling.
Just two incidents involving about six litres of crude oil have been noted so far this year by the Canada-Newfoundland and Labrador Offshore Petroleum Board after they were reported by oil companies operating about 350 kilometres east of St. John's.
The board filed three charges that are still proceeding against Suncor Energy for the spill of 26,400 litres of synthetic mud on March 28, 2011 from the Henry Goodrich drill rig. While the heavy substance is touted by energy companies as relatively benign, environmental activists say it sinks to the ocean floor where its impact on marine life has not been widely studied.
The Terra Nova offshore production vessel, also operated by Suncor, leaked almost 700 litres of lubricating oil over five months before a faulty thruster was repaired. That issue alone accounted for 22 reported incidents last year.
"That, to me, is a red flag," said Gail Fraser, a biologist and researcher at York University in Toronto who specializes in environmental management of offshore oil and gas extraction.
"What this represents is small spills that are now turning into chronic oil pollution."
Other incidents include repeated small leaks of hydraulic oil from the Terra Nova, 110 litres of lubricating oil leaked from Husky Energy's SeaRose production vessel in December 2011, and a total of 4,600 litres of synthetic-based drilling mud spilled from the drill rig GSF Grand Banks during two incidents in September and October as it was being used by Husky at the White Rose site.
Environment Canada has repeatedly said in environmental assessments for offshore projects that even small amounts of oil can be deadly for seabirds, Fraser stressed.
"They're working in one of the most diverse marine biological systems in the world," she said of oil companies at the three major Hibernia, White Rose and Terra Nova sites off Newfoundland. "And they've stated a zero tolerance for spills. There should either be no spills or, if there are spills, there should be a heavy hand from the regulator about getting these repeated problems immediately fixed.
"My question is: after the fifth thruster spill, why wasn't the Terra Nova shut down?"
The provincial government, which jointly manages the offshore with Ottawa and relies on oil money for one-third of its revenues, has fended off criticism that it's too soft on the operators who generate that cash.
Suncor spokesman John Downton said in an interview that a thruster leak began in September 2010, but it wasn't discovered until three months later. It then took weeks of planning to replace the vital piece of stabilizing equipment and a window of calm weather to haul it out of the vessel for repair the following February, he said.
"We dealt with it as soon as we could, taking into account all other considerations including vessel safety and operability."
Downton said no surface sheens or damage to seabirds were noticed and that the amount of leaking oil was estimated judging from how much more the vessel used than normal. The Terra Nova is now out of commission for several weeks of scheduled maintenance and refits.
Suncor has nothing to hide when it comes to spills, he said.
"The fact of the matter is that we report everything. If you look at the (offshore petroleum board's) website, there's reporting of everything over a litre.
"If we see anything, we report it. If it's not the way it should be, we act on it."
Sean Kelly, a spokesman for the board in St. John's, said it did not file charges related to the Terra Nova thruster leaks because there was no evidence suggesting Suncor lacked diligence.
Kelly said there is no specific spill volume threshold over which charges are laid.
Any decision to prosecute is based on diligence shown by an operator, the gravity of the offence, whether the burden of proof is likely to be met and other factors, he said in an emailed statement.
"The reporting requirements placed on companies operating in the Newfoundland and Labrador offshore area are among the most stringent in the world with operators being required to report spills less than one litre," Kelly said.
Bill Montevecchi, a research professor at Memorial University of Newfoundland in psychology, biology and ocean sciences, said governments must step up to ensure more independent reporting.
"We have observers on fishing boats because we don't ask the skippers if they've overfished," he said in an interview. "When it comes to oil companies, we accept self-reporting.
"You know, there's a real disconnect, and we're all aware of it. It just has to be acted on, but it's going to take a pretty big governmental commitment to do that."