Discovering the Impacts of Antidepressants on our Lakes
Antidepressants are a lifeline for millions of people across North America and the world. And as COVID-19 measures have taken their toll, it seems like prescriptions are growing.
Over the last two decades, an increasing number of studies have confirmed the widespread presence of pharmaceutical compounds, including those found in antidepressants, in aquatic environments.
While laboratory studies have revealed some of the possible impacts of these compounds (such as behavioural changes in fish who have demonstrated slower response times), our understanding of the fate, behaviour, and effects of these compounds in aquatic ecosystems is still limited.
That is why, in 2021, after preparatory small-scale experiments, we are exploring what happens when venlafaxine, a commonly prescribed anti-depressant, is introduced into freshwater environments.
Our research aims to discover everything from how the compounds bioaccumulate at different levels of the food web to the overall impacts on fish populations.
You can learn more about this research into antidepressants in this short blog post.
This research is being carried out in collaboration with the University of Manitoba and the University of Saskatchewan with funding from the Department of Fisheries and Oceans.
Researching Atmospheric Mercury and Freshwater Fish
After adding small amounts of tracer mercury to a small lake and its surrounding watershed for seven years (2001-2007), IISD-ELA researchers are continuing to monitor the ecosystem to see how long it takes for the mercury-contaminated lakes and fish populations to recover.
Mercury contamination of watersheds and fish by releases of mercury to the atmosphere from coal-fired power plants and smelters is an ongoing concern across the world. The ground-breaking Mercury Experiment To Assess Atmospheric Loading in Canada and the United States (METAALICUS) was the first whole-ecosystem mercury addition experiment to directly test the response of fish tissues to changing additions of mercury from rainfall. Small amounts of unique forms of mercury were added to an IISD-ELA lake and its watershed and were chemically-traced to fish tissues.
This study showed that mercury directly added to lake surfaces from rainfall will quickly accumulate in fish tissues, and that reduction of mercury in rain will decrease mercury in fish. Findings provide support for regulations proposed by the United States Environmental Protection Agency and Environment Canada to require power companies to add mercury scrubbers to their smoke stacks, at a potential cost of billions of dollars.
Click here to read more about what mercury does to fresh water, and what we are doing to reduce those impacts.
Researching the Effectiveness of eDNA Testing in Fresh Water
Environmental DNA (eDNA) can be a useful way to monitor species in ecosystems.
Even so, in flowing water systems (e.g. rivers, lake chains), local detection of species with eDNA may be confounded by the transport of eDNA from upstream. This research will work to disentangle these effects (regional versus local diversity) in natural field conditions by sampling a chain of lakes where some fish and zooplankton species are present in certain lakes but not others.
Some of the research into eDNA took place on Lake 373 at IISD Experimental Lakes Area
Similarly, many eDNA surveys only sample top layers of lakes. However, large deep lakes are stratified in the summer and winter months, with minimal mixing between the layers. Some fish and zooplankton species are known to be localised to the lower layer during the summer months because of the requirement for cold conditions, e.g. lake trout. By sampling only the surface of the lake, it is possible that eDNA surveys have lower detection probabilities for these organisms. In July of 2017 eDNA depth profiles were conducted on Lake 373 (stratified) and Lake 114 (unstratified). In October 2017 these surveys were repeated during lake mixing, to allow evaluation of stratification influences detection with eDNA.
You can learn more about this research into environmental DNA in this blog post.
This research is being conducted in partnership with Dr Joanne Littlefair and Prof Melania Cristescu from McGill University.
Investigating The Role of Cattails in Removing Phosphorus from Lakes
Could floating bioplatforms help lakes that are suffering from eutrophication?
As part of IISD’s Bioeconomy project, we have started background research on a study on eutrophic Lake 227 and oligotrophic Lake 114 comparing how cattails absorb nutrients. We have developed bioplatforms that contain cattails that float on the surface of the water.
We have developed bioplatforms of cattails to float on the surface of the lake.
We want to see if excess phosphorus in Lake 227 will enhance cattail nutrient uptake and potentially cattail growth. Research on floating wetlands continued in 2017 with new Floating Treatment Wetlands project. The objective is to deploy and establish new BioHaven floating wetland islands to continue the nutrient uptake research in Lake 227 and as part of the project in Lake 260 to look at plant and biofilm remediation of spilled oil.
You can read more information about the floating bioplatforms project in this blog post.
This research is led by Dr Richard Grosshans and is being done in collaboration with the University of Manitoba.
Discovering Indicators of Fish Productivity
We always need to understand the link between the different features of fish habitats and fish productivity, especially in the context of proposed updates to the Fisheries Act in Canada.
There are, however, some challenges.
For example, when it comes to predicting potential impacts of industrial activities on freshwater fish habitat and fish productivity, there is a lack of studies of sufficient length and spatial scale where the impacts of individual stressors on fish populations can be unambiguously evaluated. We also lack studies whereby detailed fish productivity, physical habitat, and ecosystem indicators are collected simultaneously.
Similar challenges also exist for understanding the effectiveness (and timelines) of habitat creation as an offsetting measure for the loss of fish habitat.
In this research project, we are addressing these knowledge gaps by working with our own extensive datasets on: fish community structure, productivity and behaviour; fish habitat and supporting food webs; and climate. These have been collected on non-manipulated lakes and during large-scale manipulations designed to mimic industrial activities at IISD Experimental Lakes Area.
More specifically, this project will address the following priority research priorities:
1) to develop and/or evaluate a suite of indicators that can be used to assess ecosystem impacts, and guide decisions on habitat compensation;
2) to improve our understanding of impacts to fish habitat and productivity from industrial activities; and
3) to determine the effectiveness of a newly-created diversion channel as an offsetting measure for loss of fish habitat.
This research is being carried out in collaboration with Lakehead University and Queens University with funding from Fisheries and Oceans Canada and Mitacs. This project builds on previous research whereby we determined the drivers of fish productivity.
Learning What a Common Diabetes Drug Does to a Freshwater Lake
Metformin is a drug that is commonly prescribed in North America to treat type 2 diabetes.
In 2015, 80 million prescriptions were filled out for metformin in the United States alone. Currently in Canada, 30 percent of Indigenous adults suffer from type 2 diabetes.
Metformin is not broken down in the human body, so an estimated 70 percent is excreted in urine and feces as the active pharmaceutical. The breakdown product, guanylurea, has also been shown to be metabolically active. While the fate and effects of metformin and guanylurea in the environment are not fully understood, some preliminary lab tests show inhibited growth and reproduction in fish exposed to concentrations seen in the environment.
Using small limnocorrals, we will conduct regular monitoring to learn how metformin and guanylurea impact all levels of the food web, from plants to fish.
During the summer of 2019, researchers at IISD Experimental Lakes Area will explore what happens when metformin is introduced into freshwater environments. Using small limnocorrals, we will conduct regular monitoring to learn how metformin impacts all levels of the food web, from microinvertebrates to fish.
This research is being carried out in collaboration with the Environment and Climate Change Canada, McMaster University, the School of Freshwater Sciences at the University of Wisconsin–Milwaukee, and the Alaska Department of Health and Social Services.
Flame Retardants
Since the 1960s, flame retardants have been added to common products such as electronics, building materials and upholstery fabrics.
These compounds are endocrine disruptors (i.e., they interfere with hormone systems), neurotoxins and possible carcinogens. A past IISD-ELA study looked at how certain flame retardants degrade in aquatic environments, and has already shown that breakdown products can accumulate in invertebrates, fish and sediments.
Understanding How Climate Change Affects Carbon Loading to Boreal Lakes
Seeing how the impact of climate change may affect how carbon is loaded into lakes
Lake 239 is the site of this study that explores how climate change affects carbon loading to boreal lakes.
We want to understand how climate change affects carbon loading to boreal lakes, through long-term changes in precipitation and changes in the intensity and duration of storms. New data loggers and sensors for dissolved organic carbon have been installed on two of the Lake 239 inflow streams and the lake outflow.
We also want to understand the connectivity and mechanisms by which wetlands at IISD-ELA affect the physical and chemical characteristics of stream waters.
Exploring How Selenium Accumulates in Freshwater Organisms
Selenium is a contaminant associated with mining and other industrial operations. Researchers at IISD-ELA are exploring how it accumulates in aquatic organisms.
Out on Lake 114, we are using a series of 9 mesocosms (2m in diameter) spiked with environmentally relevant concentrations of inorganic Se to investigate assimilation/biotransformation at the base of the food web and subsequent trophic transfer to primary (invertebrates) and secondary (fish) consumers.
Lake 114 is the location for this experiment exploring the accumulation of selenium in freshwater organisms.
In May 2017, there mesocosms were deployed. After two and a half months, periphyton, invertebrates and fish were collected and concentrations of Se will be determined to develop more accurate predictions of how Se accumulates in aquatic organisms.
This research is being carried out in collaboration with the University of Saskatchewan.
Tracking When Boreal Lakes Freeze and Melt
Climate change impacts when lakes freeze over and melt
Evidence from temperate zone sites around the globe has indicated a decline in the duration of ice cover due to climate change. Few such sites, however, exist in the lake-rich boreal region of Canada.
For nearly 50 years, researchers at IISD Experimental Lakes Area have been collecting measurements on the duration of ice cover, ice thickness and snow thickness. This project uses the long-term record of ice cover to develop and modify existing models of the dates when lakes freeze over (“ice-on”) and melt (“ice-off”).
Current efforts focus on improving our understanding of the role of lake size (surface area, volume) in modifying the relationship between air temperature and ice-on/ice-off dates in the boreal zone.
This ongoing work benefit from a strategic collaboration with Natural Resources Canada and the Canadian Space Agency, who are developing algorithms to estimate ice cover from the satellite constellations. The estimates that the satellites provide, once validated, will allow a broader examination of the role of lake size in modifying shifts in ice-on and off-dates resulting from climate change.
Lee Hrenchuk explains more in her recent blog post.
This research is carried out in collaboration with Natural Resources Canada.