2020 | Russian Federation | Dasha Derevyagina

Pollution-induced changes in enzyme activity in aquatic ecosystems

Water issue adressed: Too dirty
Serdyashka river

The anthropogenic load on all natural ecosystems, including rivers, currently increases.  The system of environmental biochemical monitoring of water reservoirs is used to control the biological condition of relatively clean and polluted water bodies. This system helps to identify the sources and dynamics of anthropogenic pollution.

The activity of enzymes in the aquatic ecosystems serves as an indicator of environmental conditions because it is very sensitive to changes in the state of the environment.  The aquatic biota (plants, bacteria, animals, fungi, and other organisms) produce such enzymes. They accumulate in the river and become an essential component of the ecosystem facilitating its self-purification properties.

The study goal is improvement of environmental monitoring of the rivers, using the results of the study of changes in activity of enzymes in the surface waters, bottom sediments and hydrophytes. 

The study object was river Serdyazhka which belongs to the type of small watercourses.

The topic of the research is enzyme activity in the surface waters, bottom sediments and the tissues of club-rush (scirpus lacustris). The author studied the activity of the following hydrolase enzymes: urease and oxide reductase (nitrate reductase and polyphenol oxydase). Enzyme activity was measured by spectrophotometry methods.

 Laboratory measurements were performed at Ecology and Physiology Chair of Marijsky State University.

The level of enzyme activity increases with the concentrations of substances which form the enzyme-substrate complexes with these enzymes. This level can indicate the presence of certain substances in the water reservoir and provide a measure for their concentrations.

We found out that the activity of polyphenol oxydase, nitrate reductase and urease increased when the surface runoff and household waste waters containing nitrates and phenols entered the water reservoir. This finding confirmed self-purification property of Serdiazhka river ecosystem.

The results of this study can be used for organization of environmental monitoring. The author argues for the need to observe the environmental regulation that enforces certain  restrictions for economic activities within the sanitary protection area of Serdiazhka river, with the goal to prevent pollution of the river.

Project video

This is how I came up with the idea for this project:

I decided to start with a research of small river in my republic. But then I decided to dig a little deeper and see if I can do something that could help this river. I think my project could possibly help in solving not all, but some of the problems



Polytechnic boarding lyceum

National organizer

Environmental Projects Consulting Institute (EPCI)


  • Ministry of Natural Resources and Ecology of the Russian Federation
  • Federal Agency of Water Resources
  • Coca-Cola HBC Russia
  • TVEL Fuel Company of Rosatom


Ania Andersch

Programme manager ania.andersch@siwi.org +46 8 121 360 59