狐狸视频

U of T researchers develop early warning system for water pollution using tiny water fleas

close up of a water flea on a black background
The health of common water fleas like this one are being examined by U of T researchers using a powerful instrument called a tandem mass spectrometer (photo by Don Campbell)

Researchers at the 狐狸视频 are developing an early warning system for water quality and pollution that combines tiny water fleas and an instrument so sensitive it鈥檚 able to detect changes at the molecular level. 

The technique being developed by Myrna Simpson, a professor in U of T Scarborough鈥檚 department of physical and environmental sciences, and post-doctoral researcherTae-Yong Jeong uses something called metabolomics to study the health of common water fleas (Daphnia). It uses a powerful instrument called a tandem mass spectrometer to offer a window into biochemical processes taking place inside Daphnia when they鈥檙e exposed to different water conditions. 

鈥淢etabolomics is really dynamic 鈥 it allows you to detect biochemical changes in tissues and cells almost instantaneously,鈥 says Simpson.

The technique can be incorporated into what鈥檚 called the Biological Early Warning System for water pollution, which involves looking at how organisms respond biologically to changes in water quality. The organisms used in the system usually have a fast response to pollutants and changes in nutrients, so the technique is useful for the continuous monitoring of water quality.

鈥淭he health of lakes, rivers and streams is under continuous threat from human-caused activities, and that can rapidly change the nutrient conditions, pH and water quality of ecosystems,鈥 says Simpson. 

portrait of Professor Myrna Simpson and postdoctoral fellow Tae-Yong Jeong in a lab

Professor Myrna Simpson and postdoctoral fellow Tae-Yong Jeong are developing an early warning system for water pollution that uses tiny water fleas (photo by Don Campbell)

The challenge is there hasn鈥檛 been a quick and easy method to routinely monitor these environments. Current reproductive tests on Daphnia can take up to 21 days to complete, Simpson says. A metabolomics-approach, on the other hand, can be done within minutes to hours, and even over the lifespan of the organism.

鈥淐urrent monitoring techniques are long and labour intensive,鈥 says Simpson, whose research looks at the impact of environmental change in soil and water at the molecular level.  

鈥淚n Ontario there are so many freshwater lakes and river that you can鈥檛 just collect and process samples quickly enough.鈥

Metabolomics approaches to monitoring human and environmental health have been developed in the past, but this is the first time it鈥檚 been tested for use in the Biological Early Warning System.

The technique is so granular it can detect picogram-levels (one trillionth of a gram) of metabolites in a sample. Simpson says compared to other highly sensitive 鈥渙mics鈥 measures like genomics (genes) or proteomics (proteins), metabolomics is cheaper, easier and faster.

Time and sensitivity are crucial when it comes to monitoring water quality, notes Jeong. Once Daphnia are exposed to pollutants, the toxicity can start to fundamentally alter them at a molecular level, affecting energy levels, ability to reproduce and causing genetic changes.

鈥淚f Daphnia aren鈥檛 happy because they鈥檙e affected by pollution, you will see it cascade throughout the food web,鈥 he says.

鈥淭hey are ideal to use in studying water pollution because, as a keystone organism, they鈥檙e representative of what鈥檚 happening in their surrounding environment.鈥

The research, which received funding from the Krembil Foundation and Ontario鈥檚 Ministry of the Environment, Conservation and Parks, .

The pair also authored a second paper looking at how metabolites may fluctuate over the lifespan of Daphnia, which is . 

Since metabolomics is so sensitive, an important next step for the researchers is to figure out how to tell the difference between slight metabolic changes that are caused by pollution and more extreme variations.

鈥淲e need to define what is a small change in metabolism versus a really big change that we know is going to manifest itself in something much worse,鈥 Simpson says.

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