(Reuters) - Alberta's energy regulator is investigating the deaths of 30 blue herons at a Syncrude Canada oil sands site in the northern part of the Canadian province, the agency and company said on Saturday.
The Alberta Energy Regulator said it sent investigators to the Syncrude Canada Mildred Lake site, which is about 40 km (25 miles) north of Fort McMurray.
In 2010, Syncrude was fined C$3 million ($2.29 million) for negligence in the 2008 deaths of 1,600 ducks in a toxic tailings pond, a case that fueled international concern about the environmental impact of developing Canada's oil sands.
Syncrude spokesman Will Gibson said the blue herons were found Wednesday and Thursday in a sump, or dugout, near a pump house, rather than a tailings pond.
While the company operates a system for deterring birds from landing on the tailings facilities, Gibson said it would not have been deployed in the area where the herons were found.
"Our goal is finding out what happened and ensuring that it's not repeated," he said.
Syncrude's partners include Canadian Oil Sands Ltd, Imperial Oil Ltd, Suncor Energy Inc, Sinopec, CNOOC Ltd's Nexen, Japan's Mocal Energy and Murphy Oil Co.
In November, the Alberta regulator cleared several oil sands operators of responsibility for the deaths of 196 waterfowl that landed on their toxic tailings ponds, saying poor weather forced the birds down.
Editing by Lisa Shumaker and James Dalgleish