Ontario biology student’s “sedimental journey” reveals good news for Sudbury’s lakes

Facilitating scientific research is one of the four objectives of Ontario’s Provincial Parks and Conservation Reserves Act.  This advances our learning about protected areas and enhances Ontario Parks’ ability to maintain ecological integrity.  Much of this research is conducted by universities and graduate students.  In the last two years Ontario Parks has received over 300 applications to conduct research in parks.

A PhD biology student from Queen’s University has made an important discovery that could inspire the manufacturing industry worldwide to better understand the long-term environmental damage to lakes and other bodies of water, caused by emissions that cause acid rain.  The impacts of acid rain were first noticed early on at one of Ontario’s most famous provincial parks – Killarney.


Andrew Labaj of the of the Paleoecological Environmental Assessment and Research Laboratory or PEARL, chose to study three lakes in Sudbury and two in Killarney Provincial Park to measure their recovery from acid rain caused by decades of nickel mining and smelting.

Acid rain 101

Acid rain occurs when sulfur dioxide and nitrogen oxide (the by-products of smelting and refining certain metals) enter the air and mix with water in the atmosphere to produce highly corrosive nitric and sulfuric acid. The acid then falls as rain, snow, fog or is carried by the wind. In the nickel-rich Sudbury area, one of the largest deposits in the world, the environmental damage caused by mining and smelting, caused entire species of fish to die off because the lakes were too acidic for them to thrive. The damage also spread to the soil, water table and vegetation, causing many to describe part of Sudbury as a moonscape.

“The goal of my study was to look at the changes happening in the lakes through time, and determine whether they have begun to recover”

Fascinating methodology and findings

Labaj extracted sediment samples from the bottom of three lakes in Sudbury and two in Killarney Provincial Park using a device called a corer. Then back at his lab, he extracted tiny crustaceans (known as cladocerans) buried deep within the sediment to study the health of these tiny water fleas and thereby the overall health of the lakes.

“I chose to look at the cladocerans because they live in these lakes and are feeding off the algae, and in some cases other small zooplankton species that live there,” says Labaj. “So instead of just looking at the algae, I chose to study the cladocerans because they are right in the middle of the food web and are also being preyed on by other invertebrates and fish so they give a very good representation of what is happening in the whole lake.”

According to his findings, the cladocerans, or water fleas as they are sometimes known, are flourishing and the acidity of the lakes appears to be going down.

Springing back

“After these lakes were damaged from acidification, everyone started to realize there was a problem when all the fish began to die and the landscape was becoming devegetated. There were studies done, including many from our lab, which showed the lakes were starting to become quite acidic, and that something needed to be done.

“So as a result, industry and government worked together and controls were put in place to reduce these harmful emissions. They installed what are known as exhaust scrubbers, which prevented a lot of the sulphur dioxide from going up the chimneys of the smokestacks and out into the atmosphere. That also removed a lot of the metals. The government also placed limits on the amount of emissions that were able to be put out by the metal smelters.”

Labaj says the efforts did have a “very positive effect on the Sudbury lakes” and in fact, he says, the pH levels have been significantly restored over the past 30 to 40 years, which is consistent with his findings.

Positive findings

The potential value of what Labaj studied reaches beyond the borders of Sudbury, Ontario. Labaj hopes that by studying the environmental impact of acidification caused by manufacturing and going back 40 years later to study environmental remediation efforts, there could be a take away message for other manufacturing industries worldwide.

“These lakes are recovering and that is excellent news, however, more importantly these lakes are an excellent reminder of what could happen elsewhere. There are other countries in the world, for example China and India and other places, where manufacturing occurs and where pollution is still a major threat. We can look at these Canadian lakes that experienced extremely intense acidification and get some idea of what could happen to other lakes or bodies of water in the event that an industry goes unchecked and more importantly, what happens after.”

Andrew Labaj was a Masters Student at Queen’s University when he conducted the Sudbury lakes study. He is now a PhD student at PEARL studying paleolimnology, or the study of lakes over time. The PEARL lab is a group of about 30 research scientists, post-doctoral fellows, graduate students and other scientists dedicated to using paleolimnological and other techniques to provide historical perspectives to environmental change.