Sākums Ecotoxicological studies in Latvia

Ecotoxicological studies in Latvia

In 2019 we started with the collection of biological samples for ecotoxicological studies from orphaned seal pups brought to the Zoo for rehabilitation. The samples are analysed in collaboration with University of Murcia, Spain.

Environmental pollutants represent a major threat to the ecosystems and the species that inhabit them. Environmental pollutants can be of natural or anthropic origin and their negative effects are more marked when they are present in closed ecosystems. The Baltic Sea, a sea with limited water exchange, is considered one of the most polluted seas in the world. Human activities near its shores contribute to pollution, as well as intense maritime activity. In addition, several rivers discharge their waters into the Baltic Sea, after having crossed vast agricultural areas. These waters are contaminated by chemical pollutants.

The Gulf of Riga represents one of the least studied areas of the Baltic Sea from an ecotoxicological point of view. Ecotoxicological studies are indispensable to investigate the levels of environmental pollutants. The choice of the appropriate type of animal species/sample type to be used depends primarily on the pollutant to be studied. If we use the “One Health” approach it will be necessary to study animal species whose contamination levels can be compared with those of the human species.

In photos: the samples are analysed in collaboration with University of Murcia.

Marine mammals represent, from this point of view, an excellent choice. Four species of marine mammals live in the Baltic Sea, the harbor porpoise (Phocoena phocoena), the grey seal (Halichoerus grypus), the ringed seal (Pusa hispida), the harbor seal (Phoca vitulina). In the Gulf of Riga, the grey seal is the most common species. In 2019, the Riga ZOO research team started ecotoxicological monitoring of the Gulf of Riga, analyzing samples from grey seal pups stranded on the Latvian coast and brought to the zoo’s rehabilitation center by the staff of the Nature conservation Agency (Republic of Latvia). The results of the research, developed in collaboration with the Oceanosphera research group (University of Murcia, Spain) have been presented as university theses, scientific articles, posters and presentations.


Puchades L., Gallego-Rios S.E., A. Marzio A., Martínez-López E. 2022. Trace elements in blood of Baltic gray seal pups (Halichoerus grypus) from the Gulf of Riga and their relationship with biochemical and clinical parameters. – Marine Pollution Bulletin 182: 113973. https://doi.org/10.1016/j.marpolbul.2022.113973.

Galindez Centeno I. 2021. Plomo, cromo y arsénico en tejidos internos y pelo de foca gris (Halichoerus grypus) del Golfo de Riga, Mar Báltico. (Lead, chromium and arsenic in internal tissues and fur of grey seal (Halichoerus grypus) from the Gulf of Riga, Baltic Sea.) Trabajo de Fin de Máster. Universidad de Murcia. (MSc Thesis, in Spanish.)

Puchades Guitart L. 2021. Mercurio y selenio en foca gris del Mar Báltico (Halichoerus grypus) y su relación con parámetros sanguíneos. (Mercury and selenium in grey seal from the Baltic Sea (Halichoerus grypus) and their relationship with blood parameters.) Trabajo de Fin de Máster. Universidad de Murcia. (MSc Thesis, in Spanish.)

Vīra S. R. 2021. Dzīvsudraba piesārņojums pelēkā roņa Halichoerus grypus audos Rīgas jūras līcī. Bakalaura darbs. Rīga: Latvijas Universitāte, Bioloģijas fakultāte, Zooloģijas un dzīvnieku ekoloģijas katedra. (BSc Thesis, in Latvian.)

Díaz Hurtado A. 2020. Mercurio y Selenio en foca gris (Halichoerus grypus) del golfo de Riga, Mar Báltico. Trabajo de Fin de Máster. Universidad de Murcia. (MSc Thesis, in Spanish.)

Vīra S.R. 2020. Dzīvsudraba piesārņojums pelēkā roņa Halichoerus grypus audos. Kursa darbs. Rīga: Latvijas Universitāte. (Term paper, in Latvian.)

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