Karl Johan started his master in ecotoxicology after finishing his bachelor at the same university. He is particularly interested in the interdisciplinary area between toxicology and marine biology, which was important when he chose a topic for his master thesis.
In his thesis he has analysed maternal milk of hooded seal (Cystophora cristata) from the West Ice population outside Greenland for multiple chlorinated and brominated substances. Most important are the heavy, persistent legacy contaminants like PCB and PBDE. The hooded seal is an interesting model species due to the fact that the pups are borne with a large layer of blubber and weaned from their mother after only 4-5 days. During this period, high-lipid rich milk (>60%), is transferred to the pups carrying the lipophilic contaminants that are excreted from the mother.
Karl Johan is particularly interested in investigating how the precursors are transferred between mother and pup, both prenatal and postnatal, and also how the hydroxylated (-OH) metabolites of these precursors occur in the pups.
Karl’s supervisors are: Katrine Borgå (UiO, NIVA), Gro D. Villanger (Norwegian Institute of Public Health), Anuschka Polder (Norwegian University of Life Sciences) and Ketil Hylland (UiO).
2015 Randi Grønnestad
Randi Grønnestad completed her Bachelor degree in biology at UiO and is now attending the Master’s program in biology, more specific, eco toxicology at UiO. Her master thesis is called “Levels, patterns and maternal transfer of per – and polyfluorinated compounds (PFCs), and their associations with thyroid hormones in hooded seal (Cystophora cristata) mother-pup pairs from the West-Ice”. PFCs are environmentally persistent contaminants that are present in the Arctic and with a potential to bioaccumulate and biomagnify in food webs. The aim of this study was to investigate levels and patterns of PFCs in hooded seal mother-pup pairs from the West Ice (east of Greenland), determine if these contaminants are transferred from mother to pup via milk and placenta, and to investigate possible associations between concentrations of PFCs and thyroid hormone concentrations (T3 and T4) in blood. The hooded seal has a high level in the Arctic food web and a short lactation period (only 3-4 days) with transfer of a very lipid rich milk (>60%). This makes this species a good model to investigate the transfer of chemicals through milk. No studies have previously been done to investigate levels or maternal transfer of PFCs in hooded seals, which makes this project particularly interesting. The supervisors for this project are Katrine Borgå, Gro Dehli Villanger and Anuschka Polder.
Karl Johan started his master in ecotoxicology after finishing his bachelor at the same university. He is particularly interested in the interdisciplinary area between toxicology and marine biology, which was important when he chose a topic for his master thesis.
Randi Grønnestad completed her Bachelor degree in biology at UiO and is now attending the Master’s program in biology, more specific, eco toxicology at UiO. Her master thesis is called “Levels, patterns and maternal transfer of per – and polyfluorinated compounds (PFCs), and their associations with thyroid hormones in hooded seal (Cystophora cristata) mother-pup pairs from the West-Ice”. PFCs are environmentally persistent contaminants that are present in the Arctic and with a potential to bioaccumulate and biomagnify in food webs. The aim of this study was to investigate levels and patterns of PFCs in hooded seal mother-pup pairs from the West Ice (east of Greenland), determine if these contaminants are transferred from mother to pup via milk and placenta, and to investigate possible associations between concentrations of PFCs and thyroid hormone concentrations (T3 and T4) in blood. The hooded seal has a high level in the Arctic food web and a short lactation period (only 3-4 days) with transfer of a very lipid rich milk (>60%). This makes this species a good model to investigate the transfer of chemicals through milk. No studies have previously been done to investigate levels or maternal transfer of PFCs in hooded seals, which makes this project particularly interesting. The supervisors for this project are Katrine Borgå, Gro Dehli Villanger and Anuschka Polder.