Limnologists are scientists who study the physical, chemical, and biological properties of lakes, rivers, and streams. They study abiotic characteristics, such as stratification and water chemistry, as well as biotic elements, such as aquatic vegetation, algae, microbes, and invertebrates. Limnologists and their work play a vital role in protecting freshwater resources, and Canadian researchers are global leaders in the field.

At a glance

Imagine you are at the helm of a small boat, bobbing on the waves of a large lake, about 50 metres from shore. You are a limnologist and you have spent the last few hours gathering water samples from different spots in the lake as part of an environmental assessment. You are here because a large petrochemical company wants to build a refinery on the lakeshore, but before construction can be approved, an environmental assessment must be carried out to determine the potential effects of the refinery on the surrounding environment. As an expert in aquatic ecosystems, you have joined the assessment team to investigate the impact the refinery could have on the lake's health. As a limnologist, you have been part of many environmental assessments that looked at the impact of industry on lakes and streams. Aquatic biota are sensitive to changes in their environment, making your assessment a critical component of the environmental review. You begin by gathering baseline data to give you a better picture of the current status of the lake's biotic and abiotic characteristics. You use a temperature probe to measure water temperature at different depths. Temperature changes with depth in lakes, which produces stratified layers that affect the amount of oxygen and nutrients available, influencing where biota can live. You then link physical characteristics to water chemistry, which will be determined from laboratory analysis of the water samples you've collected. You also gather data on the aquatic communities, including fish, algae, plants, and zooplankton. You can use this information on species richness and abundance to construct a food web to predict the potential impact of an industrial development, spill, or climate change scenario. All the baseline data you gather will be used to provide a picture of the water quality of the lake before the establishment of the refinery and will be included in the environmental assessment. From the environmental assessment it will be decided if the refinery project should go ahead and what the petrochemical company needs to do to ensure that the refinery's impacts are minimized.

Job duties

Duties vary significantly from job to job, but the following list includes typical job duties one might encounter as a limnologist:
  • Collect water samples and data on lake and river characteristics, for example temperature, dissolved oxygen, and fish surveys.
  • Conduct lab work such as preparing reagents and samples and performing chemical analyses, for example alkalinity, pH, conductivity, and turbidity.
  • Consult and communicate with shoreline land owners, developers, and cottagers to ensure healthy lake and stream systems.
  • Collaborate with federal, provincial, and municipal governments to manage the environmental impacts of human consumption and waste on waterways.
  • Identify fish, plants, phytoplankton, zooplankton, and other aquatic biota.
  • Conduct research, including statistical analysis of data, testing scientific hypotheses, comparisons of results to other work done, and writing reports and scientific papers.
  • Participate on technical teams preparing river basin management plans.
  • Review monitoring reports.
  • Prepare proposals for grants to support research and projects.
  • Act as an expert witness on aquatic ecosystems at Environmental Impact Assessment hearing review panels, legal proceedings, and class action suits.

Work environment

Limnologists work in a variety of locations, including: In the office:
  • Doing paperwork and analyzing data for reporting
  • Reviewing monitoring reports and Environmental Impact Assessments
  • Developing monitoring programs
  • Communicating on the phone and in meetings with clients, government departments, and the public, and presenting report findings
  • Researching new technology and advancements in limnology, and consulting with other limnology professionals
In the field:
  • Collecting water and biotic samples
  • Recording qualitative and quantitative data
  • Training and educating various stewardship groups
In the lab:
  • Studying aquatic organisms
  • Analyzing water samples for chemical variables

Where to work

There are a number of places limnologists can find employment. They include:
  • Federal, provincial/territorial, and municipal government departments
  • Colleges, universities, and research institutes
  • Environmental and engineering consulting firms
  • Not-for-profit and non-governmental environmental organizations

Education & requirements

If you are a high school student considering a career as a limnologist, you should have strong marks or an interest in:
  • Biology
  • Chemistry
  • Physics
  • Mathematics
  • English
In most cases, the minimum education requirement to work as a limnologist is a university graduate degree. If you are a post-secondary student considering a career as a limnologist, the following programs are most applicable:
  • Ecology
  • Aquatic Biology
  • Environmental Science
  • Oceanography
In addition to the above programs, most limnologists take graduate programs in limnology and aquatic ecosystems. Certification is not mandatory for limnologists, but most practitioners belong to professional groups such as the Society of Canadian Limnologists (SCL) or North American Lake Management Society (NALMS), or register as Professional Biologists.

Role Model

Michael Agbeti

It was while he was pursuing his undergraduate degree in his native Ghana that Dr. Michael Agbeti became interested in limnology, which is the study of freshwater systems such as lakes, ponds, rivers, and streams. A limnology professor encouraged Michael to consider completing an honour’s undergraduate thesis in the field. "The professor left a lasting impression on me…and that’s how I became interested in freshwater biology and eventually limnology.” Almost 30 years later, Michael is now the president of his own consulting company, Bio Limno Research & Consulting in Halifax. He spends much of his time working in the lab looking through a microscope. "I basically identify and enumerate algae and zooplankton.” The water samples Michael analyzes are shipped to him from a variety of clients, including environmental consulting companies and national or international government agencies. Michael’s responsibilities also include compiling reports, filling out paperwork and overseeing the day-to-day operation of his company. But Michael admits that he prefers his time spent behind the microscope. "I would be happy if I could just spend all of my time in the lab.” After all these years, Michael is still passionate about his profession. He enjoys looking at a lake and thinking "it appears to be clean and unpolluted to the naked eye, but it may not be so when you examine the water microscopically.” He’s also passionate about the future of limnology. "The potential for limnologists is unlimited considering the ongoing water quality problems caused by human activities, which are prevalent worldwide.”