Research in Progress

Grey seal health, immunology and toxicology research

The Baltic Sea is characterized by extremely high levels of anthropogenic pollutants. Among them are polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and per- and polyfluoroalkyl substances (PFAS), also known as endocrine-disrupting chemicals (EDCs). These pollutants pose a serious threat to both human and wildlife health — they interfere with the immune and endocrine systems, and their effects are particularly harmful to top predators in the food web, such as marine mammals, which live in chronically contaminated ecosystems. However, there is still limited knowledge about how these endocrine-disrupting compounds affect the health, immune function, and development of seal pups during the early stages of life.

The aim of our research group is to understand better the impact of these pollutants on the physiological and immune development of seals, as well as their contribution to first-year pup mortality, especially in the context of climate change. We also hope that the results of our research will contribute to the development of more effective regulatory measures and help better assess the potential health risks posed by pollution to humans, especially infants and children.

Fieldwork is conducted in Estonia, where we collect a variety of samples from grey seal pups using the most efficient methods available, minimizing disturbance to the seal haul-outs and reducing handling time with each pup. The team consists of an experienced joint group of researchers from Estonia and Lithuania.

Steroid Hormone Research

To better understand how environmental pollutants affect the development of grey seal pups, research team members Dr. Vaida Survilienė and master’s student Aistė Radzevičiūtė are analyzing steroid hormones in blood plasma and fur samples. The research is carried out in collaboration with scientists from the Faculties of Medicine and Chemistry at Vilnius University, as well as international partners at the University of Copenhagen and the Norwegian University of Science and Technology (NTNU). Advanced methods — including chromatography, mass spectrometry, and ELISA — are used to identify a broad range of hormones. The samples and techniques used allow researchers to construct a comprehensive view of hormonal changes from prenatal development through the early postnatal period.

Immune System Research

Seals are exposed to various viruses through the food chain or through contact with other animals, some of which can infect humans or are closely related to human viruses. Dr. Indrė Kučinskaitė-Kodzė, along with master’s student Tomas Vainauskas, is searching for antibodies specific to human viruses (e.g., influenza, COVID-19, mumps, measles) in the blood of seal pups. The presence of these antibodies indicates that the seals have already encountered these viruses. This study opens new perspectives on viral surveillance in seals and enhances understanding of their potential role in zoonotic transmission chains.

Grey seal behavioral research

Grey seal behaviour is diverse and subtle; it changes with age and across seasons

and is challenging to study due to these animals' aquatic and remote lifestyle

. Particularly little is known about the behaviour of young individuals, early pup development, and the effects of steroid hormones that influence the formation of the nervous, immune, and reproductive systems. Current research aims to evaluate changes in social behaviour and fluctuations in steroid hormone concentrations during the early ontogenetic period — from weaning to sexual maturity.