St Petersburg University experts discuss climate change and Arctic ecology at the White Sea Student Scientific Session–2022

The research has been supported by the Russian Science Foundation (project No 19-74-20024).

At the White Sea Student Scientific Session-2022, undergraduate and postgraduate students made oral and poster presentations on the topic areas of: Ecology; Oceanology, Geology, and Soil Science; Embryology; Molecular Biology; Zoology; and Parasitology.

Invited speakers were academics from St Petersburg University: Boris Ivanov, Associate Professor in the Department of Oceanology; and Vadim Khaitov, Associate Professor in the Department of Invertebrate Zoology.

During his presentation, Boris Ivanov spoke about the features of the climate changes in the Western sector of the Arctic. His report addressed the urgent task of determining natural seasons as illustrated by the Svalbard archipelago. According to Boris Ivanov, scientists can study the patterns and features of the regional climate through natural climate cycles.

‘As research material, we used the composite series of monthly mean surface air temperature for the period between 1911 and 2020, calculated from the data set of regular instrumental measurements at the Barentsburg hydrometeorological observatory,’ noted Boris Ivanov.

Surface air temperature (SAT) is the most widely used parameter for assessing climate change and variability.

Boris Ivanov emphasised that the main natural seasons of the year – winter (November – April), spring (May), summer (June – September), and autumn (October) – differ both in the nature of variability and in the absolute values of the average monthly SAT values. Additionally, the research identified hydrological seasons of similar duration in the coastal waters of the Svalbard archipelago.

Vadim Khaitov, Associate Professor in the Department of Invertebrate Zoology at St Petersburg University, spoke about the environmental aspects of the relationship between mussels Mytilus edulis (ME) and M. trossulus (MT), co-inhabiting the Kandalaksha Gulf of the White Sea.

‘The study analyses data on morphotype frequencies in the mussel colonies in 95 sites on the coast. For each of these coastal sites, we determined: salinity; the breaker index; mussel habitats; and remoteness from the nearest port. The revealed correlations were analysed and interpreted using experimental data and the long-term monitoring data of mussel colonies at the tip of the Kandalaksha Gulf,’ said Vadim Khaitov.

Vadim Khaitov noted that the increased frequency of detections of M. trossulus near ports is consistent with the hypothesis that the presence of M. trossulus in Northern Europe is a result of biological invasions in the White Sea. Analysis of the shells collected at the tip of the Kandalaksha Gulf in different years showed that the frequencies of the T-morphotype were considerably low in the last century. Since 2001, however, these indicators have been rapidly growing. The scientists suggest that this process may have been launched in 2000 by the emergency discharge of freshwater from the Nivskaya Hydro Power Station. Mass deaths of mussels and other aquatic organisms at the tip of the gulf were registered back then.

‘We have demonstrated that the eco-physiological performance of Mytilus edulis is declining if they share the habitat with M. trossulus. Hence, we consider MT as a stronger competitor capable of displacing ME. The spread of the M. trossulus invasion, however, may be held back by predators – starfish and oyster-catchers, who eagerly feed on mussels’, concluded Vadim Khaitov.

We should not fail to mention that 2022 is declared the Year of Zoology at St Petersburg University. The Department of Zoology was established at St Petersburg Imperial University 200 years ago. 50 years later, the University zoology and zootomy schools were officially separated – they were to become the Department of Vertebrate Zoology and the Department of Invertebrate Zoology. The zootomy school was instrumental in opening the first marine biological station in Russia on Bolshoy Solovetsky Island in the White Sea in 1881. Hence, we may speak about the 140th anniversary of marine studies at St Petersburg University. The White Sea Student Scientific Session–2022 opened the anniversary celebration programme of the Year of Zoology at St Petersburg University.