Not enough is known about the impact oil sands bitumen could have on ocean plants and animals to assess the risks of moving it through marine environments, according to a new study.
"Basic information is lacking or unavailable for several key sources of stress and disturbance, making it impossible to carry out a complete risk assessment," said the paper, which draws its conclusion from an examination of more than 9,000 papers on oil and the environment.
The paper has been peer reviewed and will be published next month in the journal Frontiers in the Ecology and Environment. Although it has been shared with the federal government, it has not been publicly released. An embargoed copy was obtained by The Canadian Press. In light of Tuesday's federal government decision to approve Kinder Morgan's Trans Mountain pipeline from the oil sands to the Pacific coast, two of its authors agreed to discuss its findings.
"The conclusions are pretty clear," said Wendy Palen of Simon Fraser University in Vancouver.
"There are large, unexamined risks to the marine environment from oil sands products and that means that the approval of new projects is problematic, maybe even bordering on irresponsible."
Bitumen is a mix of sand, clay and heavy oil. It is mined and mixed with fluids to enable it to move through pipelines.
Although the authors found reams of papers discussing the freshwater impacts of bitumen, saltwater studies are almost non-existent. The group found, for example, no examinations of how bitumen might affect food webs. Nor was there any work on the effects of bitumen spill cleanup. Basic information on toxicity is missing – partly because the exact composition of what goes through the pipe is considered a trade secret.
One of the few studies that exist found that bitumen tends to float on seawater until it weathers and churns together with sand, at which point it sinks. But even that much-publicized research was conducted in a lab, not the ocean.
"There were almost no studies on bitumen in the marine environment," Prof. Palen says.
Studies on conventional oil aren't good enough, the report says.
"Bitumen is chemically distinct from conventional oil, so ample information on the effects of conventional oil entering marine ecosystems may not apply to bitumen spills."
The report listed 12 different ways bitumen transport can impact the marine environment, from spills to the construction of new port infrastructure to the introduction of invasive species from tanker traffic. While some have been studied, most have not.
Cumulative effects have been almost completely ignored. Less than one per cent of more than 5,500 studies considered the impact of more than one stressor.
Lead author Stephanie Green, a marine biologist at California's Stanford University, said it's not clear what evidence was used to back up the Kinder Morgan decision.
"My concern as a scientist and a Canadian is that the evidence base for decisions like this be made available and transparent," she said. "I am concerned that that evidence basis is not clear and not there for some aspects of this issue."
Prof. Green said her study's conclusions are echoed by similar reviews conducted by the U.S. National Academy of Sciences and the National Oceanic and Atmospheric Administration.
"It certainly is in line with the voices of many other independent academic scientists, who really just want to see information and evidence brought to the table."
Both Prof. Green and Prof. Palen said the report underlined the urgent need for basic research on potential bitumen impacts before the Kinder Morgan line enters service, projected for 2019.
"It's challenging to do the research and understand the risks after the decision has been made," Prof. Green said. "We do still need these scientific information gaps filled as quickly as possible and re-examine the evidence basis when we have that information in hand."