Diana Manoilova does research in the field of salmonid fish biochemistry, specifically in pink salmon (Oncorhynchus gorbusha), which was introduced into rivers of the Kola Peninsula in the mid-20th century. The scientist focuses on lipids and fatty acids – biochemical molecules vital for any organism. The process of lipid breakdown, synthesis, and transport is called the lipid metabolism. It is necessary for energizing cells, building membranes, producing hormones, and many other functions.
In the case of the pink salmon, scientists are exploring the role of lipids and fatty acids in the ecological and biochemical adaptation of the fish in different developmental stages to the conditions of the White and Barents Seas, as well as in its migratory behavior: pink salmon spawns in rivers and then dies, while its young travel to the sea to feed and return to spawn a year later. This is the topic of the biologist's dissertation research. Diana Manoilova also participates in a large project on adaptations in pink salmon, carried out at the laboratory under the leadership of Academician Nina Nemova, with grant support from the Russian Science Foundation (No. 24-14-00074).
– Pink salmon has a short life span – only two years, while the average in the salmonid family is three years or more. Therefore, we’re extremely curious to find out how a species with such a short life span and no landlocked forms has managed to get integrated into new ecosystems. It is particularly fascinating to study these adaptations at the molecular and biochemical level, through lipids, which are quick to respond to environmental changes and largely determine the survival success of both individuals and the species as a whole, particularly enabling fish migration, – noted Diana Manoilova.
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Research objects: left – pink salmon smolts; right – adult breeder
In the laboratory, the young scientist analyses over 150 lipid metabolism parameters qualitatively and quantitatively. This is done by various chromatographic and molecular genetic techniques. The resulting dataset is then processed by statistical methods.
Some of the research findings have been published in scientific journals. For instance, an article on the variations in the fatty acid composition of pink salmon smolts (juveniles) from several rivers emptying into the White and Barents Seas was published in the Russian Journal of Biological Invasions. The scientists discovered that although the lipid profiles of the juveniles were generally similar, there were some significant differences between individuals from different rivers. These differences are associated with variations in the environmental factors in the smolts' habitats: water temperature, feeding conditions, and hydrological regime. The scientists have also identified key adaptation mechanisms at the level of the fatty acid spectrum during the smoltification stage, when the juvenile's body prepares for life in the sea. The study demonstrated the crucial role of lipids and their fatty acid components as one of the leading biochemical indicators in this process.
From a practical standpoint, this information matters, e.g., when developing and optimizing feed compositions for salmonid aquaculture at northern latitudes, for advancing aquaculture biotechniques, and for maintaining smoltification under artificial conditions. Overall, the results of this extensive work can be applied to create scientifically grounded approaches for the sustainable management of commercial stocks of pink salmon and other salmonid species in the Barents and White Seas. The biochemical indicators identified in these studies can be used to monitor the state of salmonid fishes and the quality of their habitats, as well as to provide additional data for catch forecasts. This may have socio-economic implications for the Russian Arctic zone.
Diana Manoilova presenting at a conference
Diana Manoilova began studying the biochemistry of invertebrates and salmonid fishes while still a bachelor’s student at the Petrozavodsk State University. She then continued with the topic in her master's programme at the PetrSU and her doctoral studies at the Karelian Research Centre RAS.
– In science, it is crucial to be part of a strong and supportive team, and I have been lucky in this regard. My research supervisor, Professor of the Russian Academy of Sciences Svetlana Murzina, truly inspired me with this topic, showing its depth and significance, and introduced me to the most subtle mechanisms and features of ecological and biochemical adaptations. My colleagues and I constantly work side by side – from the field to the laboratory, discussing results and supporting each other at conferences. Another important thing is that this work is comprehensive: it includes preparation for field surveys, conducting experiments and analytical work, data analysis, and publication of the results. All this gives me a sense of utter involvement and responsibility for what I do, – the young scientist shared.
We congratulate Diana Manoilova on receiving the presidential scholarship and wish her great achievements in her scientific endeavors and success in preparing her doctoral dissertation!
