Christian Lydersen

Seniorforsker, marinbiologi
Christian Lydersen
E-post
Telefon77 75 05 23
ArbeidsstedTromsø
Tilknytning

Aktuelle aktiviteter

  • Foraging ecology of bearded seals

During the next 3 years, we will perform a series of investigations to explore the dynamics of bearded seal foraging and the effects of these activities on benthic communities of the Arctic. We will:

  1. Complete data collection from captive bearded seal experiments in one final set of trials that includes pressure measurements (and also finish analysing and writing up the previously commenced anatomical investigations of whisker morphology and anatomy, and biokinematic studies with the captive animals);
  2. Deploy cameras on bearded seals in Kongsfjorden to document their foraging activities and its physical impacts on the substrate in the wild;
  3. Explore the relationship between the animals actual behaviour and assessments of behaviour based on dive profiles alone;
  4. Explore diet via isotope analyses of various tissues, and fatty acid profiles in bearded seals compared to potential prey and
  5. Directly explore benthic community assemblages at, near and outside bearded seal foraging areas in order to assess the impacts of bearded seal feeding on the benthic communities composition and productivity in the Arctic. In addition we will deploy state-of-the-art satellite tags in order to study the ontogeny of diving and add to our pup growth and pup-production estimates.

This work is being conducted by an international team of researchers including Drs. Kit M. Kovacs and Christian Lydersen of the Norwegian Polar Institute in Tromsø, Dr. Chris Marshall of Texas A & M University in Galveston Texas, Dr. Mark Hindell of the University of Tasmania, Hobart Australia and Dr. Mike Fedak of the Sea Mammal Research Unit, St Andrews University, St Andrews, Scotland.

  • Population biology of ringed seals (Phoca hispida) in Svalbard, Norway

The principal objective of this research programme is to provide data that will permit the assessment of population and ecological trends for ringed seals on Svalbard. The programme will also provide novel ecological knowledge about this species and essential management information for local, national and international authorities. Sub-goals of the programme include the study of

  • local population structure
  • haul-out behaviour
  • prey availability and territory size
  • density and abundance
  • population parameters 1980’s versus the present
  • seasonal diet
  • "health status" and condition
  • contaminant exposure and effects
  • and training and education of young researchers.
  • Climate impacts on the population ecology of ringed seals and polar bears at Svalbard

Climate change scenarios predict that Arctic regions will experience the most profound changes anywhere on the globe due to global warming in the coming decades. This is of great concern from a conservation and biodiversity perspective because this biome is dominated by specialists that have through evolutionary time adapted to extreme conditions, including cold temperatures and long winters – specialists that are found nowhere else on earth. Polar bears (Ursus maritimus) and ringed seals (Phoca hispida) are two such species. Both are long-lived, sea-ice-dependent, circumpolar high Arctic marine mammals. Foraging and reproductive success of these animals is directly affected by the dynamics of sea ice – which is a climate driven system. Ringed seals are the most abundant Arctic seal and are a keystone species in the Arctic marine ecosystem. Polar bears are the apex predator in this system. Both of these high trophic level animals are ideal indicators of climate- (or anthropogenic-) induced change in the Arctic system. This research programme will explore the impact of climate variability on the movement patterns, growth patterns and interactions of these two species, identify critical habitat features and develop a predictive model to assess the impact of future climate change on these animals and the ecosystem they occupy.

  • Population ecology of walruses on Svalbard
  • Walruses in Svalbard numbered in the hundreds of thousands before 3 centuries of over-harvesting brought the population to the verge of extinction. Today this stock is in an early phase of recovery; it consists of only a few thousand animals. Little is known about habitat utilization, foraging areas or behaviour in this population. This program will use satellite telemetry to identify important feeding areas for walruses. Geographical position data in combination with detailed dive information will provide novel insight into habitat use by this large pinniped. Scat analyses, isotope analyses and surveys of potential benthic prey will provide more specific information about diet. Haul-out behaviour studies, in addition to the satellite data activity budgets will permit the calculation of correction factors for aerial surveys. In addition, we will study the exposure to and effects of pollutants and conduct a general health assessment based on clinical serum chemistry parameters. We will also study the possible endocrine disruption potential of the contaminant mixtures the walruses are exposed to via their diet. Finally, based on information on haul-out behaviour from the satellite telemetry project and observational data, we will conduct a photographic aerial survey to produce a current, accurate population estimate.

Karriere

  • March 1998: Dr. philos. University of Oslo
  • Aug 1994 onward: Research Scientist, (marine mammals) - Norwegian Polar Institute Jan 1990 -
  • Aug 1994: Research scientist supported by the Norwegian Research Council, Department of General Physiology Institute of Biology, University of Oslo
  • May 1988 - Dec 1989: Research scientist at University of Oslo, Bioenergetics Group, Department of General Physiology, Institute of Biology. Responsible for scientific whaling programme (minke whales)
  • June 1986 - Dec 1987: Research scientist (term) Norwegian Polar Institute
  • March 1984 - May 1986: Contract biologist
  • 1984: MSc - Institute of Marine Biology and Marine Chemistry, University of Oslo
  • 1980: BSc - Faculty of Mathematics and Natural Sciences, University of Oslo

Interesser og spesialfelt

  • Marine mammalogy and physiology
  • Population biology
  • Ecology

Referanser

International peer reviewed journals:

Lydersen, C., Kovacs, K. M. and Hammill, M. O. 2000. Reversed molting pattern in starveling gray (Halichoerus grypus) and harp (Phoca groenlandica) seal pups. Mar. Mammal Sci. 16: 489-493.

Wolkers, H., Burkow, I. C., Lydersen, C. and Witkamp, R. F. 2000. Chlorinated pesticide concentrations with emphasis on the polychlorinated camphenes (toxaphenes), in relation to cytochrome P450 enzyme activities in Barents Sea harp seals (Phoca groenlandica). Environ. Toxicol. Chem. 19: 1632-1637.

Wathne, J. A., Haug, T., and Lydersen, C. 2000. Prey preference and niche overlap of ringed seals (Phoca hispida) and harp seals (Phoca groenlandica) in the Barents Sea. Mar. Ecol. Prog. Ser. 194: 233-239.

Dahl, T. M., Lydersen, C., Kovacs, K. M.; Falk-Petersen, S., Sargent, J., Gjertz, I. and Gulliksen, B. 2000. Fatty acid composition of the blubber in white whales (Delphinapterus leucas). Polar Biol. 23: 401-409.

Gjertz, I.; Kovacs, K. M., Lydersen, C. and Wiig, Ø. 2000. Movements and diving of bearded seal (Erignathus barbatus) mother and pups during lactation and post-weaning. Polar Biol. 23: 559-566.

Grahl-Nielsen, O., Hammill, M.O., Lydersen, C. and Wahlstrom, S. 2000. Transfer of fatty acids from female seal blubber via milk to pup blubber. J. Comp. Physiol. B. 170: 277-283.

Gjertz, I.; Kovacs, K. M., Lydersen, C. and Wiig, Ø. 2000. Movements and diving of adult ringed seals (Phoca hispida) in Svalbard. Polar Biol. 23: 651-656.

Krafft, B. A., Lydersen, C., Kovacs, K. M., Gjertz, I. and Haug, T. 2000. Diving behaviour of lactating bearded seals (Erignathus barbatus) in the Svalbard area. Can. J. Zool. 78: 1408-1418.

Bang, K., Jenssen, B.M., Lydersen, C. and Skaare, J. U. 2001 Organochlorine burdens in blood of ringed and bearded seals from north-western Svalbard. Chemosphere 44: 193-203.

Andersen, G., Kovacs, K. M., Lydersen, C., Skaare, J. U., Gjertz, I. and Jenssen, B. M. 2001. Concentrations and patterns of organochlorine contaminants in white whales (Delphinapterus leucas) from Svalbard, Norway. Sci. Total Environ. 264: 267-281.

Lydersen, C., Kovacs, K. M. and Lydersen, E. 2001. Rust-colored bearded (Erignathus barbatus) and ringed (Phoca hispida) seals from Svalbard, Norway. J. Mammal. 82: 225-230.

Gjertz, I., Lydersen, C. and Wiig, Ø. 2001. Distribution and diving of harbour seals (Phoca vitulina) in Svalbard. Polar Biol. 24: 209-214.

Gjertz, I., Griffiths, D., Krafft, B., Lydersen, C. and Wiig, Ø. 2001. Diving and haul-out patterns of walruses (Odobenus rosmarus) on Svalbard. Polar Biol. 24: 314-319.

Urashima, T., Arita, M., Yoshida, M., Nakamura, T., Arai, I., Saito, T., Arnould, J. P. Y., Kovacs, K. M. and Lydersen, C. 2001. Chemical characterisation of the oligosaccharides in hooded seal (Cystophora cristata) and Australian fur seal (Arctocephalus pusillus doriferus) milk. Comp Biochem. Physiol. B 128: 307-323.

Lydersen, C., Martin, A. R., Kovacs, K. M. and Gjertz, I. 2001. Summer and autumn movements of white whales (Delphinapterus leucas) in Svalbard, Norway. Mar. Ecol. Prog. Ser. 219: 265-274.

Van Parijs, S. M., Kovacs, K. M. and Lydersen, C. 2001. Spatial and temporal distribution of vocalising male bearded seals – implications for male mating strategies. Behaviour 138: 905-922.

Jørgensen, C., Lydersen, C., Brix, O. and Kovacs, K. M. 2001. Diving development in nursing harbour seal pups. J. Exp. Biol. 204: 3993-4004.

Wolkers, H., Burkow, I. C., Hammill, M. O., Lydersen, C. and Witkamp, R. F. 2002. Transfer of PCBs and chlorinated pesticides from mother to pup in relation to cytochrome P450 enzyme activities in harp seals (Phoca groenlandica) from the Gulf of St. Lawrence. Environ. Toxicol. Chem. 21: 94-101.

Krafft, B. A., Lydersen, C., Gjertz, I. and Kovacs, K. M. 2002. Diving behaviour of sub-adult harbour seals (Phoca vitulina) at Prins Karls Forland, Svalbard. Polar Biol. 25: 230-234.

Lydersen, C., Wolkers, H., Severinsen, T., Kleivane, L., Nordøy, E. S. and Skaare, J. U. 2002. Blood is a poor substrate for monitoring pollution burdens in phocid seals. Sci. Total Environ. 292: 193-203.

Tittlemier, S., Borrell, A., Duffe, J., Duignan, P. J., Fair, P., Hall, A., Hoekstra, P., Kovacs, K. M., Krahn, M. M., Lebeuf, M., Lydersen, C., Muir, D., O’Hara, T., Olson, M., Pranschke, J., Ross, P., Siebert, U., Stern, G., Tanabe, S. and Norstrom, R. 2002. Global distribution of halogenated dimethyl bipyrroles in marine mammal blubber. Arch. Environ. Contam. Toxicol. 43: 244-255.

Urashima, T., Sato, H., Munakata, J., Nakamura, T., Arai, I., Saito, T., Tetsuka, M., Fukui, Y., Ishikawa, H., Lydersen, C. and Kovacs, K. M. 2002. Chemical characterisation of the oligosaccharides in beluga (Delphinapterus leucas) and minke whale (Balaenoptera acutorostrata) milk. Comp. Biochem. Physiol. B 132: 611-624

Hop, H., Pearson, T., Hegseth E. N., Kovacs, K. M., Wiencke, C., Kwasniewski, S., Eiane, K., Mehlum, F., Gulliksen, B., Wlodarska-Kowalczuk, M., Lydersen, C., Weslawski, J. M., Cochrane, S., Gabrielsen, G. W., Leakey, R., Lønne, O. J., Zajaczkowski, M., Falk-Petersen, S., Kendall, M., Wängberg, S. -Å., Bischof, K., Voronkov, A. Y., Kovaltchouk, N. A., Wiktor, J., Poltermann, M., di Prisco, G., Papucci, C. and S. Gerland. 2002. The marine ecosystem of Kongsfjorden, Svalbard. Polar Res. 21: 167-208

Lydersen, C., Nøst, O. A., Lovell, P., McConnell, B. J., Gammelsrød, T., Hunter, C., Fedak, M. A. and Kovacs, K. M.2002. Salinity and temperature structure of a freezing Arctic fjord - monitored by white whales (Delphinapterus leucas). Geophys. Res. Lett. 29: art. no. 2119. 4 pp.

Karlsen, J., Bisther, A., Lydersen, C., Haug, T. and Kovacs, K. M. 2002. Summer vocalisations of adult male white whales (Delphinapterus leucas) in Svalbard, Norway. Polar Biol. 25: 808-817.

Lydersen, C., Kovacs, K. M., Ries, S. and Knauth, M. 2002. Precocial diving and patent foramen ovale in bearded seal (Erignathus barbatus) pups. J. Comp. Physiol. B 172: 713-717.

Pomponi, M., Bertonati, C., Patamia, M., Marta, M., Derocher, A. E., Lydersen, C., Kovacs, K. M., Wiig, Ø. and Bårdgard, A. J. 2002. Polar bear hemoglobin and human HbAo: same 2,3-diphosphoglycerate binding Site but asymmetry of the binding? Hemoglobin 26: 363-371.

Van Parijs, S.M., Lydersen, C. and Kovacs, K. M. 2003. Male reproductive behaviour in the aquatic mating bearded seal (Erignathus barbatus). Anim. Behav. 65: 273-283.

Sørmo, E. G., Skaare, J. U., Lydersen, C., Kovacs, K. M., Hammill, M. O. and Jenssen, B. M. 2003. Partitioning of persistent organic pollutants in grey seal (Halichoerus grypus) mother-pup pairs. Sci. Total Environ. 302: 145-155.

Van Parijs, S.M., Lydersen, C. and Kovacs, K. M. 2003. Sounds produced by individual white whales, Delphinapterus leucas from Svalbard during capture. J. Acoust. Soc. Am. 113: 57-60.

Urashima, T., Nakamura, T., Yamaguchi, K., Munakata, J., Arai. I., Sato, T., Lydersen, C. and Kovacs, K. M. 2003. Chemical characterization of the oligosaccharides in milk of high Arctic harbour seal (Phoca vitulina vitulina). Comp. Biochem. Physiol. A. 135: 549-563.

Reder, S., Lydersen, C., Arnold, W. and Kovacs, K. M. 2003. Haul-out behaviour of high Arctic harbour seals (Phoca vitulina vitulina) in Svalbard, Norway. Polar Biol. 27: 6-16.

Grahl-Nielsen, O., Andersen, M., Derocher, A. E., Lydersen, C., Wiig, Ø. and Kovacs, K. M. 2003. Fatty acid composition of the adipose tissue of polar bears and of their prey: ringed seals, bearded seals and harp seals. Mar. Ecol. Progr. Ser. 265: 275-282.

Van Parijs, S.M., Lydersen, C. and Kovacs, K. M. 2004. The effects of ice cover on the behavioural patterns of aquatic mating male bearded seals. Anim. Behav. 68: 89-96.

Wolkers, H., Lydersen, C. and Kovacs, K. M. 2004. Accumulation and lactational transfer of PCBs and pesticides in harbor seals (Phoca vitulina) from Svalbard, Norway. Sci. Total Environ. 319: 137-146.

Kleivane, L., Severinsen, T., Lydersen, C., Berg, V. and Skaare, J. U. 2004. Total blubber burden of organochlorine pollutants in phocid seals; methods and suggested standardization. Sci. Total Environ. 320: 109-119.

Lydersen, C., Nøst, O. A., Kovacs, K. M. and Fedak, M. A. 2004. Temperature data from Norwegian and Russian waters of the northern Barents Sea collected by free-living ringed seals. J. Mar. Syst. 46: 99-108.

Wolkers, H., Bavel, B. van, Derocher, A. E., Wiig, Ø., Kovacs, K. M., Lydersen, C. and Lindström, G. 2004. Congener-specific accumulation and food chain transfer of polybrominated diphenyl ethers in two Arctic food chains. Environ. Sci. Technol. 38: 1667-1674.

Urashima, T., Nakamura, T., Nakagawa, D., Noda, M., Arai, I., Saito, T., Lydersen C. and Kovacs, K. M. 2004. Chemical characterization of the oligosaccharides in bearded seal (Erignathus barbatus) milk. Comp. Biochem. Physiol. B 138: 1-18.

Andersen, S. M., Lydersen, C., Grahl-Nielsen, O. and Kovacs, K. M. 2004. Autumn diet of harbour seals (Phoca vitulina) at Prins Karls Forland, Svalbard assessed via scat and fatty-acid analyses. Can. J. Zool. 82: 1230-1245.

Pomponi, M., Gavuzzo, E., Bertonati, C., Derocher, A. E., Lydersen, C., Wiig, Ø. and Kovacs, K. M. 2004. Hemoglobin, pH and DPG/chloride shifting. Biochimie 86: 927-932.

Lydersen, C. and Kovacs, K. M. 2005. Growth and population parameters of the world’s northernmost harbour seals (Phoca vitulina) residing in Svalbard, Norway. Polar Biol. 28: 156-163.

Birkeland, A., Kovacs, K. M., Lydersen, C. and Grahl-Nielsen, O. 2005. Transfer of fatty acids from mothers to their calves during lactation in white whales (Delphinapterus leucas). Mar. Ecol. Progr. Ser. In press

Hofmeyr, G. J. G., Krafft, B. A., Kirkman, S. P., Bester, M. N., Lydersen, C. and Kovacs K. M. 2005. Population changes of Antarctic fur seals at Nyrøysa, Bouvetøya. Polar Biol. In press.

Andersen, G., Foreid, S., Skaare, J. U., Jenssen, B. M., Lydersen, C. and Kovacs, K. M.. 2005. Levels of toxaphene congeners in white whales (Delphinapterus leucas) from Svalbard, Norway. Sci. Total Environ. In press.

Wolkers, H., Lydersen, C., Kovacs, K. M., Burkow, I. and Bavel, B. van (2005). Accumulation, metabolism, and food chain transfer of chlorinated and brominated contaminants in subadult white whales (Delphinapterus leucas) and narwhals (Monodon monoceros) from Svalbard, Norway. Arch. Environ. Contam. Toxicol. In press.

In addition:

Co-author on 1 book, 29 oral presentations/posters in international conferences, 4 reports in English and 4 publications in other languages.

Supervision of students

  • Aili Labansen, MSc
  • Carina Johansen, MSc
  • Eli Skoglund, MSc
  • Carla Freitas, PhD
  • Bjørn Krafft, PhD

11 MSc students graduated