I am ecotoxicologist who completed my PhD degree at the department in September 2018.
I have been interested in how life history affects pollutant levels in organisms. Does the energy an individual put towards growth or reproduction lead to different tissue concentrations of pollutants in the environment? In many species of marine mammals, we find lower levels of pollutants in females than in males because females can offload contaminants to their offspring.
What are the processes behind this? Which factors influence life history strategies and consequently alter pollutant levels? I have used different methods (meta-analysis, field and lab) to answer some of these questions. Taxa have included pinnipeds (seals, sea lions and walruses), seabirds and Arctic-breeding geese. I have investigated reproductive investment in mothers, timing of migration and energy source. In summer 2016, I travelled to Kongsfjorden in Svalbard to look at barnacle geese (Branta leucopsis) and their eggs. This was followed by pollutant analysis which I carried out in Tromsø January-March 2017.
My research interests are in the fields of ecotoxicology, life history theory and statistical modelling.
Hitchcock, Daniel James; Andersen, Tom; Varpe, Øystein; Loonen, Maarten; Warner, Nicholas Alexander; Herzke, Dorte; Tombre, Ingunn; Griffin, Larry R.; Shimmings, Paul & Borgå, Katrine (2019). Potential Effect of Migration Strategy on Pollutant Occurrence in Eggs of Arctic Breeding Barnacle Geese (Branta leucopsis). Environmental Science and Technology.
53(9), s 5427- 5435 . doi:
Arctic-breeding geese acquire resources for egg production from overwintering and breeding grounds, where pollutant exposure may differ. We investigated the effect of migration strategy on pollutant occurrence of lipophilic polychlorinated biphenyls (PCBs) and protein-associated poly- and perfluoroalkyl substances (PFASs) and mercury (Hg) in eggs of herbivorous barnacle geese (Branta leucopsis) from an island colony on Svalbard. Stable isotopes (δ13C and δ15N) in eggs and vegetation collected along the migration route were similar. Pollutant concentrations in eggs were low, reflecting their terrestrial diet (∑PCB = 1.23 ± 0.80 ng/g ww; ∑PFAS = 1.21 ± 2.97 ng/g ww; Hg = 20.17 ± 7.52 ng/g dw). PCB concentrations in eggs increased with later hatch date, independently of lipid content which also increased over time. Some females may remobilize and transfer more PCBs to their eggs, by delaying migration several weeks, relying on more polluted and stored resources, or being in poor body condition when arriving at the breeding grounds. PFAS and Hg occurrence in eggs did not change throughout the breeding season, suggesting migration has a greater effect on lipophilic pollutants. Pollutant exposure during offspring production in Arctic-breeding migrants may result in different profiles, with effects becoming more apparent with increasing trophic levels.
Hitchcock, Daniel James; Varpe, Øystein; Andersen, Tom & Borgå, Katrine (2017). Effects of reproductive strategies on pollutant concentrations in pinnipeds: a meta-analysis. Oikos.
126(6), s 772- 781 . doi:
Bizarro, Cristina; Eide, Marta; Hitchcock, Daniel James; Goksøyr, Anders & Ortiz-Zarragoitia, Maren (2016). Single and mixture effects of aquatic micropollutants studied in precision-cut liver slices of Atlantic cod (Gadus morhua). Aquatic Toxicology.
177, s 395- 404 . doi:
Hitchcock, Daniel James; Loonen, M. J.; Warner, Nicholas Alexander; Herzke, Dorte; Tombre, Ingunn; Shimmings, Paul; Griffin, L. R.; Varpe, Øystein; Andersen, Tom & Borgå, Katrine (2018). Migration effects on pollutants in eggs of Arctic - breeding geese.