10/04/2012 07:34 EDT | Updated 10/04/2012 09:47 EDT

Tailings Ponds Ducks: Alberta Oil Sands Operators' Defence Case Too Strong, Says Prosecutor Susan McRoy

This Sept. 19, 2011 aerial photo shows a tar sands tailings pond at a mine facility near Fort McMurray, in Alberta, Canada. Environmentalists hoping to block a proposed underground oil pipeline that would snake 1,700 miles from Canada to the Gulf of Mexico have pinned their hopes on an unlikely ally _ the conservative state of Nebraska where opposition to Keystone XL pipeline has risen steadily since the project was proposed three years ago. Public hearings will start Sept. 27, in Lincoln on the 16-inch steel pipe that if built would carry oil extracted from tar sands in Alberta, Canada, through Montana, South Dakota, Nebraska, Kansas and Oklahoma to refineries in Texas. (AP Photo/The Canadian Press, Jeff McIntosh)

The companies involved in a case that saw 550 ducks killed when they landed in an Alberta oilsands tailings pond have too-strong a defence, which is why no charges will be laid, the Crown announced Thursday.

The decision not to level charges against the energy giants lay solely with the fact prosecutors would likely not get a conviction against the operators - Syncrude and Suncor - if the case was taken to court, said Crown Prosecutor Susan McRoy in Edmonton.

McRoy said she looked at the entire investigation and asked herself, “do I have a reasonable expectation of conviction looking at the evidence that’s been gathered? And my conclusion is no.

“The companies involved (would) be successful in using the defence of due diligence and, that being said, I’m honbour-bound not to preceed on charges I do not feel I can win.”

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Listen to McRoy's statement:

A similar incident in 2008 saw 1,600 birds killed when they landed in another Syncrude pond. That event resulted in Syncrude being given the largest environmental penalty in Alberta history, reported the Globe and Mail at the time.

But this incident was much different, said McRoy

“In 2008, the deterrent were not out at all… this was a very different case in that the deterrents were in fact operating,” she said.

“Was there perfection? No

“But I have a different test that I have to consider and that is reasonable expectation of conviction.”

Dr. Colleen Cassady St. Clair, a leading expert from the University of Alberta on human-wildlife encounters and the deterrence methods used to mitigate conflicts, said what the ducks faced that night was a perfect storm.

"Birds landed on six different ponds in the oil sands region. We have weather records that make me quite convinced that weather was a primary factor in when the birds landed," she said.

"Really inclement conditions with very unfavourable winds must’ve been the reason that they decided to land. And that storm would’ve also been the reason why they landed where they did."

But St. Clair said the scientific community has learned a lot from the incident and discussed new methods that can be implemented to prevent adverse landings in the future.

Her full statement is here:

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