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Features
Update 2019/5/13
Research - IISD Experimental Lakes
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IISD ONTARIO EXPERIMENTAL LAKES: THE ONLY LAB OF ITS KIND IN THE WORLD
By Suzanne Forcese
The International Institute for Sustainable Development (IISD) Experimental Lakes Area (ELA) is one of the world's most influential freshwater research facilities. It features a collection of 58 small lakes and their watersheds in northwestern Ontario, Canada. By manipulating these small lakes, scientists are able to examine how all aspects of the ecosystem - from the atmosphere to fish populations - respond.
"It is the only lab of its kind in the world," Sumeep Bath of the IISD told WaterToday. Because all life depends on water, researchers at ELA are studying the impacts of contaminants, providing evidence with real world ecosystems to help governments make better decisions to help protect our water and our planet.
"Most of our projects actively manipulate the lakes to mimic what is happening in the real world," Bath added. The researchers then are able to make recommendations. One important experiment that helped change water policy around the world was ELA's research on algal blooms. Algae are an important nutrient in the food web. However, when the concentrations become too high, algal blooms increase.
Algal blooms are dense layers of tiny green plants that occur on the surface of lakes and other bodies of water when there is an overabundance of nutrients (primarily phosphorus) on which algae depend. This effect is called eutrophication and is often caused by human pollution, such as wastewater, sewage, manure and fertilizer runoff from agriculture. The green scum formed by dense algal blooms is unsightly, smells bad and makes water toxic to humans and fish, causing illness and even death. "When algae die, they are decomposed by bacteria, removing oxygen from the water, killing fish."
The research involved dividing the lake with a vinyl curtain. Carbon and nitrogen were added to the water on one side of the curtain and carbon, nitrogen and phosphorus were added on the other side. The side to which the carbon and nitrogen were added remained clear while the side with the phosphorus, carbon and nitrogen turned green with algal blooms. This confirmed that nitrogen and phosphorus were the cause of algal blooms. Phosphorus alone was added to the water in later experiments resulting in algal blooms. By reducing the amount of phosphorus, blooms could not grow.
This was a ground breaking discovery that resulted in stricter controls in Canada in the use of fertilizers on agricultural land. Further this led to the label "phosphorus free" on many products such as dish soaps, detergents, shampoos, and lawn fertilizers by informed companies.
Another experimental project that Bath referred to was the effect of mercury on the lake. Mercury is a naturally occurring element found in low concentrations in soil. It is also a waste by-product of coal burning, mining, smelting, oil refining and cement production. It is often released into the atmosphere by industrial emissions and falls in rain onto our land, lakes and rivers where it may be converted by bacteria into methyl mercury which is highly toxic to humans and animals. It also makes its way into bacteria which are then eaten by invertebrates and up the chain to small fish and larger fish. The higher up the chain, the higher the concentration of methyl mercury.
In high concentrations mercury is poisonous affecting the nervous systems of people.
The mercury research involved a 7 year study. Each year, researchers at ELA added 1/6 teaspoon of inorganic mercury in a lake and surrounding landscape to mimic the mercury that would fall in rain. The surrounding forest and wetland
were sprayed by plane while the lake itself was contaminated by boat. This allowed the scientists to distinguish between new mercury and naturally occurring mercury and to determine which kinds affected which parts of the ecosystem. It was discovered that mercury added directly to the lake resulted in rapid increases of methyl mercury concentrations in fish and other aquatic life. The mercury added by plane took longer to accumulate in the lake, suggesting that mercury falling in rain directly on the lake has an immediate impact while mercury entering it from runoff remains for years.
"The interesting and encouraging thing was," Bath added "that when mercury was no longer being added directly to the lake, the methyl mercury levels in small fish declined." Within 4 years there was an 80% decline. "This was strong evidence for limiting mercury emissions. Cutting off the source had a huge impact."
As a result of this research both Canada and the United States have proposed new laws to reduce mercury emissions from coal fired power plants.
In one of the experimental lakes researchers created a small reservoir in a wetland pond by building a small dam at the outflow in order to study the impact of flooding. The findings showed that both carbon dioxide and methane, an especially potent greenhouse gas, were produced in higher levels after flooding, suggesting that reservoirs can be sources of GHGs.
This research led to the widespread recognition of the inclusion in inventories of global GHG production. Subsequent calculations also indicated that in most cases hydroelectric power produces lower levels of GHGs than fossil fuel sources.
Researchers from the Freshwater Institute in Winnipeg who worked at ELA identified that reservoir creation often leads to unsafe concentrations of mercury in fish. Flooding, it was determined, does not create new mercury, but creates conditions that favor and increase the conversion by bacteria of mercury existing in flooded soils and vegetation to methyl mercury which enters the food web.
Reservoir creation and management also affect fish production. Reservoirs often feature seasonal and daily drawdowns of water level. As a part of their research scientists explored the potential effect of these drawdowns in a whole-ecosystem experiment by dropping the water level of a 15-metre deep lake by 2-3 metres thereby mimicking drawdowns in northern hydroelectric reservoirs. The result was a decrease in food supply and habitat for fish. The fish failed to reproduce and would likely have died out completely had the experiment continued longer.
This was another important discovery that will help IISD's work. They collaborate with hydroelectric companies, governments, and other groups as dams continue to be built around the world. Strategic timing of drawdowns can help minimize the negative impacts on the life cycles of fish.
WaterToday also spoke with Scott Higgins, the invasive species specialist at IISD. Higgins told WT that "there was a key event in Canada in the mid 1980's when zebra mussels arrived in the Laurentian Great Lakes in the ballasts on Trans-Atlantic ships. By 1991 they were in the Mississippi River and had made their way down to the Gulf of Mexico by 1996 moving within drainage systems into rivers and lakes. Now over 1000 lakes have been invaded and there will be more."
What makes zebra mussels so effective at taking over the waters of the world is their enormous reproductive capacity and ability to survive. One female will produce 1 million eggs per spawn. Extreme temperatures do not affect them. The
few natural predators - fish with strong jaws and birds - are barely enough to make a significant impact on the numbers. In dry hot weather they simply hole up in their shells and wait for better conditions.
"It is extremely challenging," Higgins admits. "And much too dangerous to risk introducing them into the ELA." So for now the best solution - "We have to learn to live with them." Fortunately most people who are concerned about the mussels are also concerned about the lakes and are taking measures to decrease their populations. "They have to be vigilant in keeping boats and trailers clean every time they are in the water - even if it is for a second." Microscopic veliger which are the larvae of the zebra mussels are attached to aquatic plants and can become attached to boats and trailers that are in water even for a short time. "The Province of Manitoba has very strict regulations now based on this research. Authorities have the power to impound boats and trailers of anyone who is not adequately cleaning them."
Higgins says the zebra mussels attach to hard surfaces like rocks and decks. There are certain paints that one can use which prevent the mussels from attaching to decks and boat launches. Copper also is something that repels the creatures.
Higgins is involved in a winter project on the experimental lakes in collaboration with Natural Resources. Using a satellite, they are looking for applications around ice cover specifically in linking how climate change is affecting and has affected ice changes over the past 50 years.
Looking ahead to the summer months of 2019 the ELA has several new projects underway that are certain to shape the way policy makers look at different issues.
It had been observed that after flooding in lake communities a type of invertebrate called mysis (a fresh water shrimp) had not repopulated. Experiments this summer will calculate what happens when this species will be reintroduced into a lake.
Another very important study to take place will be the FOREST Project - Freshwater Oil Spill Remediation Study.
The emerging contamination from pharmaceuticals is another serious concern. One specific study that will be undertaken will be to look at the drug metformin - the drug used to treat type 2 diabetes. Currently in Canada 30% of Indigenous adults suffer from type 2 diabetes. This becomes extremely significant when we realize that metformin is not broken down in the human body but excreted in the urine and feces as the active pharmaceutical. This active product called guanylurea then makes its way into wastewater and eventually into rivers and lakes. Preliminary lab tests have shown inhibited growth and reproduction in fish exposed to concentrations seen in the environment of the metabolically active breakdown product of this pharmaceutical.
During the summer of 2019 researchers will explore what happens when metformin is introduced into freshwater environments to learn how all levels of the food web are impacted.
ELA will also be monitoring a remote lake for microplastics. In a recent study IISD ELA found densities of around 1 microplastic particle for every square metre of water. There is evidence that these particles can act as vectors of contaminants and carry these harmful substances to fish.
Higgins also said that they were hoping to launch a project looking at the effects of cannabis on the environment. "There is an enormous amount of water used in grow- ops and we need to examine how the run-off of water mixed with cannabinoids will affect the watershed and our lakes."
Both Higgins and Bath expressed their excitement and passion working in a team that is involved in a living lab that is impacting the world view of our lakes.
Visitors may tour the ELA either as individuals or groups. https://www.iisd.org/ela/visitors/visitor-information/
IISD's independent, evidence-based approach to the development of policy recommendations and tools complements the facility's strong scientific foundation. IISD and the ELA strengthen efforts to address global freshwater issues to create innovative policy solutions for regional and global water management. IISD is an independent think tank promoting human development and sustainability.
suzanne.f@watertoday.ca
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