Experimental Lakes

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7:00 min.

Teacher's Guide


There are some scientific experiments that are so big, they cannot be done in a lab. That is why a small corner of Northwestern Ontario has been set aside for the scientists with those big ideas. It is called the experimental lakes area. Fisheries and Oceans scientists are trying to replicate what happens on a much larger scale elsewhere, for example acidification of lakes or flooding of peat bogs and dry forest. Their findings are now used to help mitigate the environmental impact of projects such a hydro electric dams.

Transcript of Video

Jill Deacon
There are some scientific experiments that are so big, they can't be done in a lab. That's why a small corner of Northwestern Ontario has been set aside for the scientists with those big ideas... it's called the experimental lakes area, and lately it's been taking a pretty good BEATING in the name of science.

Jay Ingram
This is a lab like no other. Its test tubes are entire lakes... nearly 60 of them. Its Petri dish is the Canadian Shield.

It's far from any city development... Its pristine waters remain unpolluted by any industrial run-off.

Non identified Male voice
Well, this place was established 32 years ago now... it's relatively remote in terms of the watersheds not having people living in them.

Jay Ingram
The watersheds that feed the Experimental Lakes are pretty much as they were thousands of years ago... long before people and machines started to spew emissions into the air.

Senior biologist John Shearer calls its one of the largest laboratories in the world.

Dr. John Shearer
We are trying to use a... a small scale natural system to replicate what happens on a much larger scale in other parts of the country, or perhaps even other parts of the world.

Jay Ingram
It was here during the 70's and 80's that scientists conducted ground-breaking studies on the effects of acid rain. They polluted entire lakes... and measured the results. They were attempting to duplicate the effects of sulphur emissions on the thousands of eastern Canadian lakes. Their results put Canada at the forefront of the fight to reduce acid rain. They helped to change laws that forced big corporations to take more environmental responsibility.

Today the same test site is being used to assess the effects of Hydro Electric development.

Hydro projects generate energy using water. Huge tracts of land are often flooded, to harness water power.

For years, people called these kinds of developments the "clean solutions" to our increasing energy needs.

But the findings of the Experimental Lakes tell a different story.

Dr. John Shearer
There was a new idea around that reservoirs may be significant sources of greenhouse gases to the atmosphere, and we wanted to test that idea.

Jay Ingram
Greenhouse gases had long been associated with burning fossil fuels. Could hydro electric development have the same sort of nasty side effects?

Drew Bodaly came to the Experimental Lakes to find out.

He and his colleagues built dikes at the end of this lake to simulate a hydro reservoir. The small lake grew by five fold. Trees died... and the thick peat bogs began to decay under a metre-and-half of water.

And that produced startling results.

Drew Bodaly
We got methyl mercury concentrations in water that were 20 times what they were before flooding... we got significant movement of greenhouse gases like carbon dioxide and methane into the atmosphere.

Jay Ingram
The mercury and gases bubbled up through the water, by-products of decaying plant life... But it didn't stop there. Scientists found elevated levels of mercury in the fish. And they know that once it gets into the food chain, it threatens humans.

Although mercury occurs naturally in the soil, flooding seems to concentrate it. As for the greenhouse gases, they are still being released... six years after the flooding. Scientists say that could continue for the next century.

They've found, in extreme cases, the "once clean" energy solution can produce one third as much greenhouse gas as a coal-fired generator... and that's long been considered the dirtiest method of generating power.

But hydro electric projects don't just flood marshy wetlands, sometimes a dry forest becomes part of a reservoir and the next phase of the study will compare the two.

These wooden walls are holding back a pool of water more than two meters deep. Three giant reservoirs have been constructed on a high point. Scientists are eager to see how the mercury and greenhouse gas levels compare to those in the wetlands area.

Jay Ingram
They take air samples several times a day. Bubble traps float in the reservoir. Each morning a syringe is used to draw off trapped gas. Water samples are tested on site at the Experimental Lakes own lab-complex. Chemical tests identify how much oxygen is in the water. That's an important measure, because the breakdown of organic material and production of greenhouse gases consume oxygen. The loss of oxygen in the water means that that reservoir is emitting gas.

Scientists don't think the upland forest will produce as much mercury or greenhouse gas as the marshy wetland. A dry forest doesn't have a thick carpet of peat... and it's the decay of the peat that is the largest contributor of greenhouse gases in hydro reservoirs.

By combining data from the wetland reservoir with the new information pouring out of flooded forests, hydro electric planners should be able to develop computer models that will project the environmental costs of their dams.

Several hydro companies have already taken notice of the findings. They've redesigned plans to avoid flooding marshy areas.

Drew Bodaly
Well it makes me feel good... makes me... uh..it's fun to be out here and do research and I enjoy it... I enjoy being in the field, but it's nice to know that your results are being used in the real world, and... uh... it's nice when hydro electric companies do apply your results and do take these environmental effects into account when they're planning hydro electric projects.

Jill Deacon
Tonight's Earth Tones was produced with the help of the Department of Fisheries and Oceans.