Professor, dr.scient Stein Kaartvedt


Picture of Kaartvedt   Graduate employment:
Academic degree:
Dr. Scient.
Telephone: (+47) 22 85 47 39
Fax:       (+47) 22 85 44 38

University of Oslo
Department of Biology
Pb. 1064, Blindern
N-0316 Oslo, Norway

  • 1989: Dr. Scient, University of Bergen
  • 1982: Cand. real., University of Bergen

• 1992-present: Professor in marine zoology (associate professor in 1992), University of Oslo
• 2000-2003: Head Biology Department, University of Oslo
• 1991-1992: Post-doctoral scholar, Woods Hole Oceanographic Institution, USA
• 1987-1991: Research scientist, Institute of Marine Biology, UoBergen
• 1985-1987: Assistant Prof of Marine Biology, UoB (substitute)
• 1983-1985: Research Scientist, Institute of Marine Research, Bergen

Research abroad:

• Sept-Dec 2004: Guest Scientist, Woods Hole Oceanographic Institution, USA
• Nov 1998-Nov 1999: Guest scientist, School of Zoology, Tasmania, Australia, and Woods Hole Oceanographic Institution, USA
• Aug 1991-Aug 1992: Post-doctoral scholar, Woods Hole Oceanographic Institution, USA

Research areas, interest:

My research group exploits the opportunities offered by easily accessible and deep fjord basins for studies of distribution, behavior, mortality and feeding of zooplankton. Most focus has been on the copepods Calanus finmarchicus and Paraeuchaeta norvegica, and the krill Meganyctiphanes norvegica. Current projects on copepods aim at unveiling state-dependent variations in vertical distribution of P. norvegica, and assessing their feeding using molecular methods. Projects on krill aim at characterizing swimming behavior in relation to time of day and feeding mode, and evaluate implications for encounters with predators.  

To unveil the biology of zooplankton, it is necessary to know their predators, and studies of distribution, feeding and swimming behavior of planktivorous fish represent a central part of the research activities. Current projects address Norway pout (Trisopterus esmarki), whiting (Merlangius merlangus), herring (Clupea harengus) and sprat (Sprattus sprattus).

We apply echosounders in concurrent studies of fish and plankton. To illustrate, the echogram below displays the diel vertical migration of macroplankton and fish at a 120 m deep site in the Oslofjord. The blue layer located at ~70-90 m at day mainly consists of the krill Meganyctiphanes norvegica, the fish below are Norway pout while the red layers above the krill (most prominent the second day) consist of schooling clupeids.

Echogram displaying a diel cycle at a 120 m deep station, and a selected section outlining data in greater detail, showing the 3-d swimming pattern of a single fish (identified as Norway pout) at about 100 m depth. Color scales display strength of the echo (TS; left), which provides information on size, and swimming speed (right)

Echogram displaying a diel cycle at a 120 m deep station, and a selected section outlining data in greater detail, showing the 3-d swimming pattern of a single fish (identified as Norway pout) at about 100 m depth. Color scales display strength of the echo (TS; left), which provides information on size, and swimming speed (right)

Split-beam echo sounders hold the opportunity of defining the position of an organism in the acoustic beam, and by applying software allocating subsequent echoes to the same target, so-called “target tracking” provides data on size, 3-D swimming trajectories and swimming speed of individuals. Target tracking can normally only be done with the echosounder (transducer) located relatively close to the targets. Therefore, submerged systems are used to address deep-living fish. A bottom-mounted, upward looking transducer was used to obtain the results presented in the lower half of the figure above.

Submersible systems are also used for in situ target tracking of plankton in deep water, as exemplified below for plankton occurring at ~80 m depth in the Oslofjord. When lowering the transducer into what appears as a diffuse echo-layer by a hull mounted transducer, single individuals become resolved, and individual plankton can be studied in their natural habitat.

3D echograms

Selected publications (since 2000):
  1. Bucklin, A., Kaartvedt, S., Guarnieri, M., Goswami, U. (2000). Population genetics of drifting (Calanus spp.) and resident (Acartia clausi) plankton in Norwegian fjords. J. Plankton Res. 22: 1237-1251
  2. Olsen, E. M., Jørstad, T., Kaartvedt, S. (2000). The feeding strategies of two large marine copepods. J. Plankton Res. 22: 1513-1528
  3. Bagøien, S., Kaartvedt, S. Øveraas S. (2000). Seasonal vertical migration of Calanus spp. in Oslofjorden. Sarsia 85: 299-311
  4. Kaartvedt, S. (2000). Life history of Calanus finmarchicus in the Norwegian Sea in relation to planktivorous fish. ICES J. Mar. Sci. 57: 1819-1824
    Dale, T., Kaartvedt, S. (2000). Diel patterns in stage specific vertical migration of Calanus finmarchicus in habitats with midnight sun. ICES J. Mar. Sci. 57: 1800-1818
  5. Torgersen, T., Kaartvedt, S. (2001) In situ swimming behaviour of individual mesopelagic fish studied by split-beam echo target tracking. ICES J. Mar Sci. 58: 346-354
  6. Bagøien, E., Kaartvedt, S., Aksnes, D.L., Eiane, K. (2001) Vertical distribution and mortality of overwintering Calanus. Limnol. Oceanogr. 46: 1494-1510
  7. Dale, T., Kaartvedt, S., Ellertsen, B., Amundsen, R. (2001) Large scale oceanic distribution and population structure of Calanus finmarchicus in relation to physical environment, food and predators. Mar Biol 139: 561-574
  8. Fleddum, AL., Kaartvedt, S., Ellertsen, B. (2001) Distribution and feeding of the carnivorous copepod Paraeuchaeta norvegica in habitats of shallow prey assemblages and midnight sun Mar Biol 139: 719-726
  9. Kaartvedt, S., Dale, T., Bagøien, E., Viken, T. (2002) Bi-modal vertical distribution of the carnivorous copepod Paraeuchaeta norvegica. J Plankton Res 24: 155-158
  10. Kaartvedt, S., Larsen, T., Hjelmseth, K., Onsrud, M.S.R. (2002) Is the omnivorous krill Meganyctiphanes norvegica primarily a selectively feeding carnivore? Mar Ecol Prog Ser 228: 193-204
  11. Torgersen T, Karlsbakk E, Kaartvedt S (2002) Deviating vertical distribution and increased conspicuousness in parasitized Calanus. Limnol Oceanogr 47: 1187-1191
  12. Skarra, H, Kaartvedt S (2003) Vertical distribution and feeding of the carnivorous copepod Paraeuchaeta norvegica Mar Ecol Prog Ser 249: 215-222
  13. Klevjer, TA, Kaartvedt S (2003) Split-beam target tracking can be used to study the swimming behavior of deep-living plankton in situ. Aquat. Liv. Res. 16: 293-298
  14. Båmstedt, U., Kaartvedt, S., Youngbluth, M. (2003) An evaluation of acoustic and video methods to estimate the abundance and vertical distribution of jellyfish. J Plankton Res 25: 1307-1318
  15. Schøyen, M, Kaartvedt S (2004) Vertical distribution and feeding of the copepod Chiridius armatus Mar Biol 145: 159-165
  16. Fiksen Ø, Varpe Ø, Kaartvedt S (2004) Reply to Horizons Article ”Some ideas about the role of lipids in the life cycle of Calanus finmarchicus” Irigoien (2004): II J Plankton Res 26: 980
  17. Onsrud, MSR, Kaartvedt S., Røstad, A., Klevjer, T.A. (2004) Vertical distribution and feeding patterns in fish foraging on the krill Meganyctiphanes norvegica. ICES J Mar Sci 61: 1278-1290
  18. Vestheim, H, Kaartvedt, S., Edvardsen, B (2005) State-dependent vertical distribution of the carnivore copepod Pareuchaeta norvegica. J Plankton Res 27: 19-26
  19. Vestheim H, Edvardsen B, Kaartvedt S (2005) Assessing feeding of a carnivorous copepod using species-specific PCR. Mar Biol 147: 381-385
  20. Onsrud MSR, Kaartvedt S, Breien, MT (2005) In situ swimming speed and swimming behaviour of fish feeding on the krill Meganyctiphanes norvegica Can J Fish Aquat Sci 62: 1822-1832
  21. Kaartvedt S, Røstad A, Fiksen Ø, Melle W, Torgersen T, Breien MT, Klevjer T (2005) Piscivorous fish patrol krill swarms. Mar Ecol Prog Ser 299:1-5

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