An international team of scientists analyzed errors and gaps in the world's articles on freshwater salinization. To cope with the global problem of salinization of continental waters, the authors call on the international scientific community to focus joint efforts on several priority areas of research using interdisciplinary approaches. The new research agenda is published in the journal Trends in Ecology and Evolution.

Salt entering freshwater lakes and rivers seriously degrades the quality of water around the world. Mining, intensive agriculture, water abstraction, use of salt-containing mixtures on roads - these and other activities lead to an increase in the concentration of salts in many continental waters. Salt can not only make water unfit for drinking and industrial use. Among other serious consequences of salinity for water bodies, experts indicate the extinction of salt-sensitive species and spread of harmful species, changes in the cycle and transfer of organic matter through food chains, and increase in greenhouse gas emissions.

Despite increasing evidence for the severe effects of salinization, current knowledge is insufficient to predict the effects of this process on freshwater ecosystems. To fill this gap, a team of scientists from ten countries, including a scientist from the Krasnoyarsk Science Center of SB RAS, joined forces to identify the most urgent research needs. The review article, published in Trends in Ecology and Evolution, is the result of a series of webinars "Great Challenges in Aquatic Ecology" within the framework of the European research infrastructure project AQUACOSM-plus. Due to COVID-19, the meetings were held in a webinar format, allowing for greater international participation and inspiring the team to communicate globally.

After reviewing several hundred papers published over the past five years, the authors emphasize that most research focuses on North America and Europe, while areas with increasing salinization, such as Africa or South America, are largely ignored. In most of the current research, scientists are "overlooking" small water bodies, such as ponds, which are very important for the conservation of regional biodiversity. There is very little information about the impact of various types of salt on water bodies and response of the entire water body as an integral ecosystem to salinization. Most papers evaluate the effect of excess salts on crustaceans or insect larvae. However, understanding the response of an ecosystem, in this case, requires information on the impact of salinity on micro-organisms that manage nutrient cycling and on representatives of the upper trophic links, including fish, reptiles, and amphibians.

“We have developed a research program to fill the gaps in our knowledge. In this paper, we list the main directions for future research and suggest experiments, methods or approaches which will contribute to answering urgent questions, ” explains David Cunillera-Moncusi, lead author of the article, a young scientist from the Austrian research center WasserCluster Lunz.

Salinization threatens lakes and rivers and the lives of people depending on them. To solve this problem, joint activities of the scientific community, experts, local communities, and politicians are needed. The efforts of the international group of scientists who published the review article are aimed at outlining ways to move forward, as well as to draw the attention of the international community to the global danger.

“We rarely think that salt in water can be a problem. However, in many regions of the world, in particular in Russia, salinization of water or soil is a large-scale process. We have been dealing with natural salt lakes in Krasnoyarsk for a long time. One of the world's most notable teams has been formed here. Recently, this research team has begun to investigate how the inhabitants of freshwater bodies are affected by the road salts widely spread at present. In Russia, they began to be intensively used not so long ago, but, for example, in the United States, they are already sounding the alarm. Decades of salt use on roads have led to an increase in salt levels in groundwater and formerly surface freshwater. The water inhabitants are dying, the quality of water is declining, passing into another class of suitability for domestic or industrial purposes. The fact that our research agenda is published in the first-row world's environmental journal suggests that this is indeed a global issue. It is a pleasure and an honor to be among those who set trends,” explains one of the authors of the article, a leading researcher at the Institute of Biophysics SB RAS, Candidate of Biological Sciences Egor Zadereev.