Syncrude apologized for the 350 ducks that had to be put down after landing on their tailings pond near Fort McMurray.

"I'm very upset about this whole situation," Syncrude president Scott Sullivan said Wednesday.

"There's 5,500 people out here proud to be Syncrude employees and I'm proud to represent them and this is not what we want to have happen."

But Sullivan could not guarantee that there would be no further duck deaths on his company's site.

Syncrude Canada reported Tuesday that 230 ducks had to be put down due to contact with bitumen floating on the surface of the tailings pond. That number later rose to 350 the following day.

The province also confirmed that other oil companies Suncor and Shell also had ducks die after landing at some of their tailings ponds.

Suncor said at least 40 ducks are dead after landing on one of its tailings ponds.

Shell confirmed that one bird was found dead on a road and another was found at Albian Village work camp. Shell also said its crews observed that two birds were oiled at the Muskeg River mine tailings pond, but were unable to capture them.

Shell said its bird deterrent systems at Shell Albian Sands were fully implemented and operational at the time of the incident. They added there were only two ducks found in their company's Albian sands tailings pond.

Syncrude said the unusual bird activity at their Mildred Lake Settling Basin, the company's largest pond with 220 million cubic metres of tailings liquid, was due to a freezing rain storm in the area. But on the Environment Canada website, there is no record of precipitation last night in that area.

The waterfowl deterrent system had been in full operation at the time and extra air cannons, flare guns and air horns had been used, but with no response, Syncrude added.

Less than a week ago, Syncrude was ordered to pay $3 million in fines after more than 1,600 dead or dying ducks were found in a tailings pond in April 2008. It was the largest environmental penalty in Alberta's history.

The Pembina Institute said this latest incident of migratory waterfowl dying in the ponds adds weight to their argument that the bitumen mining industry needs to stop using tailings ponds to contain its effluent.

"The issue can be resolved if tailings ponds are phased out of oil sands production. That's the real culprit here," said Nathan Lemphers of the Pembina Institute.

"The government has allowed 840 billion litres of toxic tailings to accumulate on the landscape and that's after 40 years of unchecked production. So the government needs to get serious about reducing the amount of tailings on the landscape and enforcing the existing environmental regulations."

Alberta Environment Minister Rob Renner said tailings ponds will likely never completely disappear, but claims they will shrink in size and in quantity.

With files from CTV Edmonton