Toxic pollutants released by oil sands mining operations are accumulating in freshwater ecosystems, research by Canadian scientists suggests.
A study of sediment in nearby lakes showed the level of pollutants, known as PAHs, had risen since the 1960s when oil sands development began.
However, the researchers added that PAH concentrations were still lower than those found in urban lakes.
The findings appear in the Proceedings of the National Academy of Sciences.
PAH refers to polycyclic aromatic hydrocarbons – a group of chemicals that have been shown to affect aquatic organisms and birds. PAHs have also been described as being responsible for damaging food crops.
The chemicals occur naturally in coal, crude oil, and petroleum; they are also present in products made from fossil fuels, such as creosote and asphalt.
PAHs also can be released into the air during the burning of fossil fuels and organic matter – the less efficient the burning process, the more PAHs are given off. Forest fires and volcanoes produce PAHs naturally.
Digging the dirt
Using sediment cores from five lakes within a 35km (22-mile) radius of major oil sands facilities and one remote lake (90km/56 miles from the facilities), the researchers assessed the ecological impact of oil sands developments on freshwater ecosystems.
Core samples showed a rise in PAH concentrations since the development of oil sands mining
Analysis of the samples showed that PAH levels were now 2.5-23 times greater than levels from about 1960.
Core samples showed a rise in PAH concentrations since the development of oil sands mining
In their paper, the team wrote: “PAH ratios indicate temporal shifts from primarily wood combustion to [decomposed organic material] sources that coincide with greater oil sands development.
“Canadian interim sediment quality guidelines have been exceeded since the mid-1980s at the most impacted sites.”
Oil sands, also known as tar sands, have only recently considered to be a viable component of the world’s oil reserves as a result of rising energy prices and the development of technology that has made its processing profitable.
These factors has resulted in a marked increase in the extraction and processing of oil sands in northern Alberta and Saskatchewan, which account for 97% of the nation’s proven reserves and is the world’s third largest reserve.
The researchers say that in 1980, daily production was 100,000 but has grown to about 1.5 million barrels a day, It is projected to reach 3.7 million barrels by 2025, they added.
The development of the oil sands sector has been controversial, prompting polemic between those in favour of utilising the resource to cushion the Canadian economy from shocks in global energy prices and those who say the environmental costs are too high.
Press secretary for Environment Minister Peter Kent
In 2010, The Star newspaper reported that concerned residents on the shores of Lake Athabasca (downstream from one of the region’s major oil sands facilities) had called for the federal government to commission an independent study to assess the impact on the area’s water bodies.
The call came after local people said a growing number of landed fish where showing signs of deformities.
They voiced concern that there was not an effective system of environmental monitoring was in place.
At the time, the federal environment minister said he was listening to calls for a monitoring programme.
The researchers behind the PNAS study said that there was conflicting findings among the few long-term PAH datasets that existed, with some suggesting increases in limited areas, while other recording no increase between the 1950s and 1998.
“Establishment of background PAH concentrations and historic loadings is essential and would allow the impacts of development, including industrial PAH contributions, to be compared with the natural range… in lake sediment from the region,” they wrote.
“As noted repeatedly in previous assessments of the impacts of the Alberta oil sands operations, insufficient monitoring data and a poor understanding of pre-development conditions have attempts to determine the scope of pollution from oil sands development.”
The team concluded that the findings from their study had to be considered in a wider environmental context.
“As a consequence of climate warming, the physical processes that lakes experience can be altered,” they said.
“Longer ice-free season and enhanced thermal stability, coupled with higher surface-water temperatures and the redistribution of nutrients within the water column, contribute to greater algal production within many lake ecosystems.”
They concluded: “Analyses of sediment cores from five lakes near major oil sands operations and remote Namur Lake demonstrate that modern PAH concentrations and fluxes, including DBTs, are well above ‘natural’ pre-development levels.”
But, they added: “The ultimate ecological consequences of decades-long increases in aquatic primary production, coupled with greater PAH loadings to lakes in the oil sands region, are unknown and require further assessment.”
Adam Sweet, press secretary for Canada’s Environment Minister Peter Kent, said the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring, announced in February 2012, was committed to a “scientifically rigorous, comprehensive, integrated, and transparent environmental monitoring program for the region.
“It is important to note that the results in this paper come from field studies that were conducted prior to the announcement of the Joint Plan,” he told BBC News.
“In fact, the Joint Plan was created, and implemented, to address the very concerns raised by such studies – it was designed to provide an improved understanding of the long-term cumulative effects of oil sands development.
“Canada has strong rules and regulations in place to ensure that the Canadian environment is protected, and our government will continue to ensure that Canada’s oil sands are developed responsibly.”
There appear to be “remarkable similarities” between fish deformities found downstream from Alberta’s oilsands and those observed after the Exxon Valdez oil spill in Alaska and after Florida’s Deepwater Horizon disaster, says a renowned ecologist.
David Schindler of the University of Alberta has written an open letter to two federal cabinet ministers pointing out the recent research findings from scientists as far afield as the Gulf of Mexico.
“Given the parallels in the cases from various locations, it seems likely that some chemical or suite of chemicals in crude oil is causing the malformations,” Schindler wrote.
He’s proposing that Canada take the lead in researching the issue by isolating the various chemical compounds and introducing them to fish stocks in a controlled setting.
And Schindler says the federal Experimental Lakes Area – which has been shut down by Ottawa for a savings of about $2 million annually – is the ideal natural laboratory for the work.
In a letter Wednesday to Fisheries Minister Keith Ash-field and Environment Minister Peter Kent – copied to a number of U.S. scientists and some news media – Schindler praised the monitoring work of government scientists in the Athabasca River.
But he said such monitoring can’t possibly determine which chemicals may be affecting aquatic life due to the “complex chemical soup” found downstream from industrial oilsands development.
What’s required, the scientist said, “would be whole ecosystem experiments where small amounts of selected chemicals are applied to whole lakes, and the effects determined on several key species in the food chain.”
It’s tailor-made for the federal Experimental Lakes Area in northwestern Ontario, a remote region of 58 pristine lakes that have been used since 1968 for groundbreaking freshwater studies on everything from nutrient-loading and mercury exposure to acid rain.
The Harper government announced last year it was closing the world-renowned facility as a cost-saving measure – although insiders say the operating cost of the facility is only $600,000 annually, of which a third comes back in user fees.
Fully funded independent researchers have been refused access to the site to continue their research this summer, although Ottawa is in negotiations with the province of Ontario and other parties to transfer management.
Linking the closure of the Experimental Lakes Area – a cause celebre among Canada’s scientific research community and environmentalists – with oilsands pollution is a potentially toxic political mix for the government.
Activists have already claimed climate-change research at the ELA is the real reason the Conservatives closed the facility.
A spokeswoman for Ashfield did not directly address Schindler’s proposal when reached for comment, but said in an email “the government continues to actively work toward establishing a new operator for the ELA site so that research there can continue.”
Erin Filliter added that “freshwater science continues to be conducted across Canada at multiple facilities which more than adequately meets the needs of government research.”
Similarly, Rob Taylor at Environment Canada said by email that “Minister Kent is very engaged in the environmental monitoring of the oilsands region.” “The Canada-Alberta joint scientific monitoring program has been put in place to study any impact on air quality, water quality and biodiversity,” said Taylor.