How do these tiny fleas help lake water quality?

Published: May 13, 2020 · Updated: May 19, 2020

Daphnia Photo by Choksawatdikorn/Shutterstock

Dedicated cottagers who regularly monitor their lake water could soon help study lake health around the world. The Friends of the Muskoka Watershed—working with a professor from the U.K.’s University of Birmingham, and with the help of Canadian cottagers—is developing a tool that uses daphnia (water fleas) to assess water quality problems and their causes.

Where can I get the quality of my lake water tested?

Daphnia are microscopic crustaceans that live in freshwater lakes worldwide and are quickly affected by changes in the environment. “Daphnia have a huge number of genes evolved to respond to environmental conditions,” says freshwater biologist Norman Yan, the chair of the FMW and a York University professor emeritus. “We will be looking for that genetic response, and its correlation with the physics, chemistry, and predators in the exposure waters or lakes.”

Daphnia show signs of adapting to such environmental gradients as temperature, eutrophication, and calcium and phosphorous levels. By exposing them to sampled lake water, and studying their reactions, scientists can assess lake conditions and diagnose water problems. For example, if a lake has low calcium levels, daphnia might respond by making proteins to cope with these conditions.

The team is working to receive funding for the project; next steps involve testing lake water across Ontario, and eventually, Canada. If all goes well, volunteers will be collecting samples and sending them for analysis in 2017.

“The dream is that one day every single lake is going to be tested,” says Yan. “We are not going to be able to do that without the help of hard-working volunteers—a lot of cottagers who love their lakes.”

This story was originally published in the Summer 2016 issue of Cottage Life.

Read about Norman Yan’s research on acid rain in cottage country.

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