WCVM scientist measures oil spill toxicity
Oil is undoubtedly on the minds of many Canadians today — especially when they're confronted by the depressing news images of oil-soaked waterfowl and dead fish following an oil spill.
By Logan Hahn
While these scenes of ravaged ecosystems are sickening, they merely scratch the surface of the environmental devastation that follows a spill.
Polycyclic aromatic hydrocarbons or PAHs have long been considered the king contaminants in oil spills, and their most troubling characteristic is long lasting effects in an ecosystem.
Studies suggest that some PAHs can hide out under rocks and soil, a time bomb waiting to be uncovered and still toxic years after the spill. Additional evidence indicates that some PAHs can alter an organism's genetic makeup resulting in the defunct DNA being passed on to its offspring — preserving the pollutant's damaging effects over generations.
"What people do not realize is that oil spills are very common," says Lynn Weber, a toxicologist and associate professor at the Western College of Veterinary Medicine (WCVM) who has been researching PAHs for nearly 15 years.
"If you looked into it, you would probably see a spill every week, but we only hear about the massive spills like BP Horizon," says Weber, referring to the 2010 explosion of an oil drilling rig owned by British Petroleum (BP) that released an estimated 700,000 cubic metres of oil into the northern Gulf of Mexico.
"Aside from the spills, in every urban area there is water washed over roads that picks up PAHs and brings them right into our waterways. Boats, through releasing their bilge and spilling fuel, also contribute PAHs to the environment. We are continuously releasing PAHs into the water through petroleum and oil."
Weber and her research team at the WCVM are employing cutting-edge techniques aimed at surveying the immediate toxic effects of oil contamination. For some time now, it has been known that PAHs found in oil cause cancer and various birth defects in fish. Although these chronic toxic effects are readily apparent, measuring acute toxicity is far more complex than searching for tumours or strange-looking fish larvae.
One of their innovative tools is a swim tunnel apparatus, essentially a treadmill for fish, which measures oxygen consumption as a fish swims against a predetermined flow speed. This technique enables researchers to study whether a fish exposed to oil contaminants will tire more quickly. Fish that are less physically fit are more prone to predation, resulting in changes in the food chain.
The WCVM's newest ultrasound machine is another remarkable piece of technology that's capable of producing highly detailed images of fish hearts. That's great news for the researchers who are working with zebrafish, organisms that are commonly used in toxicological studies but are diminutive in size.
Although the zebrafish's one-microlitre heart is difficult to see with the naked eye, the high-resolution ultrasound machine enables researchers to measure a host of cardiovascular parameters seldom gathered in fish studies.
"Probably only two or three other people in the world are doing fish cardiac ultrasound," says Weber. "Our work requires very advanced techniques that many fish biologists are not well-versed in."
As Weber investigates ways to apply her research, she's considering the possibility of doing whole ecosystem exposures at an experimental lake. That move from the lab to the field could potentially capture the interest of regulators and industry, but it's something that Weber and her research team are prepared for: they're dedicated to uncovering immediate effects and garnering more attention from the public.
And since the Canadian government has vowed to be more cognizant of environmental issues, the WCVM researchers' studies could have large, real-world implications at a time when oil sands and pipelines are part of politicians' daily conversations.
The Natural Sciences and Engineering Research Council of Canada (NSERC) provided funding for this research through Weber's NSERC Discovery Grant.
Logan Hahn is a third-year student in the U of S College of Arts and Science (Physiology and Pharmacology) whose summer research position was supported by an NSERC Undergraduate Summer Research Award. Logan's story is part of a series of stories written by WCVM summer research students.
Polycyclic aromatic hydrocarbons or PAHs have long been considered the king contaminants in oil spills, and their most troubling characteristic is long lasting effects in an ecosystem.
Studies suggest that some PAHs can hide out under rocks and soil, a time bomb waiting to be uncovered and still toxic years after the spill. Additional evidence indicates that some PAHs can alter an organism's genetic makeup resulting in the defunct DNA being passed on to its offspring — preserving the pollutant's damaging effects over generations.
"What people do not realize is that oil spills are very common," says Lynn Weber, a toxicologist and associate professor at the Western College of Veterinary Medicine (WCVM) who has been researching PAHs for nearly 15 years.
"If you looked into it, you would probably see a spill every week, but we only hear about the massive spills like BP Horizon," says Weber, referring to the 2010 explosion of an oil drilling rig owned by British Petroleum (BP) that released an estimated 700,000 cubic metres of oil into the northern Gulf of Mexico.
"Aside from the spills, in every urban area there is water washed over roads that picks up PAHs and brings them right into our waterways. Boats, through releasing their bilge and spilling fuel, also contribute PAHs to the environment. We are continuously releasing PAHs into the water through petroleum and oil."
Weber and her research team at the WCVM are employing cutting-edge techniques aimed at surveying the immediate toxic effects of oil contamination. For some time now, it has been known that PAHs found in oil cause cancer and various birth defects in fish. Although these chronic toxic effects are readily apparent, measuring acute toxicity is far more complex than searching for tumours or strange-looking fish larvae.
One of their innovative tools is a swim tunnel apparatus, essentially a treadmill for fish, which measures oxygen consumption as a fish swims against a predetermined flow speed. This technique enables researchers to study whether a fish exposed to oil contaminants will tire more quickly. Fish that are less physically fit are more prone to predation, resulting in changes in the food chain.
The WCVM's newest ultrasound machine is another remarkable piece of technology that's capable of producing highly detailed images of fish hearts. That's great news for the researchers who are working with zebrafish, organisms that are commonly used in toxicological studies but are diminutive in size.
Although the zebrafish's one-microlitre heart is difficult to see with the naked eye, the high-resolution ultrasound machine enables researchers to measure a host of cardiovascular parameters seldom gathered in fish studies.
"Probably only two or three other people in the world are doing fish cardiac ultrasound," says Weber. "Our work requires very advanced techniques that many fish biologists are not well-versed in."
As Weber investigates ways to apply her research, she's considering the possibility of doing whole ecosystem exposures at an experimental lake. That move from the lab to the field could potentially capture the interest of regulators and industry, but it's something that Weber and her research team are prepared for: they're dedicated to uncovering immediate effects and garnering more attention from the public.
And since the Canadian government has vowed to be more cognizant of environmental issues, the WCVM researchers' studies could have large, real-world implications at a time when oil sands and pipelines are part of politicians' daily conversations.
The Natural Sciences and Engineering Research Council of Canada (NSERC) provided funding for this research through Weber's NSERC Discovery Grant.
Logan Hahn is a third-year student in the U of S College of Arts and Science (Physiology and Pharmacology) whose summer research position was supported by an NSERC Undergraduate Summer Research Award. Logan's story is part of a series of stories written by WCVM summer research students.