SAINT JOHN, N.B. -- A manager at the Canaport liquefied natural gas facility in Saint John says there's little it can do in the next few weeks to prevent more migrating birds from flying into a flare that's burning at the plant.

Fraser Forsythe said Thursday the latest estimate is that about 7,500 migrating birds died while the company was burning off excess gas at the facility on Friday and Saturday.

The plant is in the middle of making changes to equipment at the facility to reduce the amount of flaring, Forsythe said, but completion of the project is still several weeks away.

In the meantime, he said the plant cannot compromise safety to prevent birds from being killed again.

"We find ourselves in a dilemma here. The flare system is a safety-release system to ensure we can maintain normal operating pressures in the plant," he said in a telephone interview.

As the liquefied natural gas boils off, some of it has to be released or it poses a safety risk to the facility, added Forsythe.

"At the moment there's not a whole lot I can do to resolve it in the short term."

He said a project to install a high-pressure compressor for the gas has been underway since 2011.

"As we commissioned it we have been flaring," he said. "Unfortunately for us we're just a few weeks away from getting that compressor up and operating."

Forsythe said the plant was originally designed to move large amounts of gas on a continuing basis, but the markets have changed and more of the gas is stored now and shipped during peak demand times.

"For many months of the year we're idling along and we started this (compressor) project to avoid flaring during that period of time," he said.

Forsythe said he's been informed by Environment Canada that an investigation is underway, but he hasn't been informed if any charges are being considered under environmental protection laws.

LNG is natural gas that has been chilled into a liquid state, making it easier to transport in specialized tankers.

Tankers full of natural gas, chilled into a liquid state, arrive at Canaport, where the fuel is converted back into a gas and transported to Canadian and U.S. markets by pipeline.

The plant is owned by Repsol, which holds a 75 per cent interest, while Irving Oil of Saint John has a 25 per cent share in the facility.

Jim Wilson, a New Brunswick birder and naturalist, said large numbers of birds die each month because of various hazards, but last weekend's incident was among the most dramatic in recent years.

"All of these things when you combine them contribute to a decline in bird life," he told radio station News 88.9 in Saint John. "Every time one of these things happen it's significant."