Per Carlsson,
Associate Professor

My research has constantly centered into a deeper understanding of different processes and interactions in the marine microbial pelagic food web (including larger zooplankton). More specific, I have been working with marine and limnic bacterial carbon utilization and nutrient limitation in temperate and Antarctic waters, phytoplankton ecology in Swedish, Brazilian and Mediterranean marine waters (utilization of organic bound nitrogen (in connection with bacteria, heterotrophic/mixotrophic flagellates and ciliates), toxin production in dinoflagellates and cyanobacteria, and zooplankton experimental ecology (grazing on toxin producing phytoplankton and uptake of phytoplankton toxins and their effects on zooplankton egg production and survival).

Presently, I am interested in vertical migration by dinoflagellates (in cooperation with Therese Jephson) and the effects of climate change on marine phytoplankton: I am studying the effects of increased runoff of dissolved organic matter on coastal phytoplankton and the effects of increased water temperature on sinking rates of non-motile phytoplankton. I am also studying the effects of cyanobacterial toxins on the food web in connection to decaying blooms.

Ongoing projects

2010-2012: Occurrence and significance of cyanobacterial toxins in northern Öresund during a summer bloom, funded by the Krapperup Foundation (300 000 SEK)

2009-2011: How is the pycnocline in Öresund affecting vertically migrating toxin producing dinoflagellates?, funded by the Krapperup Foundation (175 000 SEK)

2010-2011: The significance of pycnoclines in marine waters for vertically migrating toxin producing phytoplankton”, funded by Carl Trygger Foundation (150 000 SEK)

Selected publications

Jephson T, Fagerberg T, Carlsson P (in press) Dinoflagellate vertical migration dependency on salinity stratification. Aquatic Microbial Ecology.

Fagerberg T, Jephson T, Carlsson P (2010) Molecular size of riverine dissolved organic matter influences marine coastal phytoplankton communities. Marine Ecology Progress Series 409: 17-25

Jephson T, Carlsson P (2009) Species- and stratification-dependent diel vertical migration behaviour of three dinoflagellate species in a laboratory study. Journal of Plankton Research 31: 1353-1362

Fagerberg T, Carlsson P, Lundgren M (2009). A large molecular size fraction of riverine high molecular weight dissolved organic matter (HMW DOM) stimulates growth of the harmful dinoflagellate Alexandrium minutum. Harmful algae 8:823-831

Kozlowsky-Suzuki B, Karjalainen M, Koski M, Carlsson P, Stolte W, Balode M, Granéli E (2007) Disruption of the microbial food web and inhibition of metazooplankton develoment in the prescence of iron- and DOM-stimulated Baltic Sea cyanobacteria. Mar Ecol Prog Ser 337:15-26

Stolte W, Balode M, Carlsson P, Grzebyk D, Janson S, Lips I, Panosso R, Ward CJ, Granéli E (2007) Stimulation of nitrogen-fixing cyanobacteria in a Baltic Sea plankton community by land-derived organic matter or iron addition. Mar Ecol Progr Ser 327:71-82

Kozlowsky-Suzuki B, Carlsson P, Rühl A, Granéli E (2006) Food selectivity and grazing impact on toxic Dinophysis spp. by copepods feeding on natural plankton assemblages. Harmful Algae 5:57-68

Granéli W, Carlsson P, Bertilsson S (2004). Bacterial abundance, production and organic carbon limitation in the Southern Ocean (39-62 °S, 4-14 °E) during the austral summer 1997/1998. Deep-Sea Research II. 51:2569-2582

Carlsson P, Caron DA (2001). Seasonal variation of phosphate limitation of bacterial growth in a small lake and its dependence on grazing activity and temperature. Limnology and Oceanography. 46:108-120

Carlsson P, Granéli E, Segatto AZ (1999). Cycling of biologically available nitrogen in riverine humic substances between marine bacteria, a heterotrophic nanoflagellate and a photosynthetic dinoflagellate. Aquatic Microbial Ecology. 18: 23-36

Carlsson P, Segatto AZ, Granéli E (1993) Nitrogen bound to humic matter of terrestrial origin-a nitrogen pool for coastal phytoplankton? Mar. Ecol. Prog. Ser. 97: 105-116.