Federal scientists at the Bedford Institute of Oceanography are studying the behaviour of diluted bitumen from the Alberta oil sands when it spills into the ocean.

They're finding it poses real challenges for any cleanup.

"It is to a certain degree tougher to work with than conventional oil," says Thomas King of the Department of Fisheries and Oceans.

In 2013 Ottawa launched an $8 million program to evaluate what happens when diluted bitumen spills into the ocean, how it can be treated and the impact it has on the environment.

Industry wants to move more oil sands petroleum by tanker, pipeline and rail, but little was known about its behaviour in a spill.

"There is no literature on it, no reports," says King

Research so far shows a bitumen spill is treatable — with booming and skimming, even burning in situ -— provided there is a rapid response.

Diluted bitumen weathers quickly, meaning it gets heavy.

Chemical dispersants have been found to be less effective on diluted bitumen than conventional oil.

The dilutant — light oil used to make it fluid — evaporates leaving behind tar balls that sink.

"When it begins to sink it becomes more troublesome. We have to figure out ways to track, monitor and remediate sinking oil," King says.

DFO is expanding its research to examine effects in brackish and fresh water. Right now a $720,000 upgrade of the BIO wave tank facility is underway.

International Interest

Fresh-water research will address issues raised when an Enbridge pipeline carrying diluted bitumen ruptured into a lake in Michigan in 2010.

It floated for several days and then sank. The cleanup required dredging the lake.

King has presented some of his findings to the U.S. National Academy of Sciences.

China is collaborating on the research

"There is a vast interest in the international science world," King said.

International scientists peer reviewing the research have rejected attempts by dutiful Canadian scientists to brand the pollutant as oil balls, says King.

Instead he says they are still referred to as tar balls.