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PRELIMINARY NOTES ON THE ARCTIC SEA ICE BIOTA IN SUMMER 2001 Johanna Ikävalko 1 & Tuomo Roine 2 1 Finnish Institute of Marine Research, Finland 2 University of Helsinki, Finland. ARCOP. Arctic Ocean Expedition 2001 ATMOSPHERIC PROGRAMME.
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PRELIMINARY NOTES ON THE ARCTIC SEA ICE BIOTA IN SUMMER 2001 Johanna Ikävalko1 & Tuomo Roine2 1Finnish Institute of Marine Research, Finland 2University of Helsinki, Finland ARCOP
Arctic Ocean Expedition 2001 ATMOSPHERIC PROGRAMME • Particle (liquid particles, bacteria, fractions of diatoms...) release within the pack ice region • atmosphere • Importance of aerosols, in particular di-methyl-sulfate (DMS) compounds, in nucleation, i.e. cloud formation in regional/global scale
AIMS OF BIO STUDIES • DMS compounds produced in the Arctic summer ice? • which DMS producing and other organisms are present? • abundance of organisms, in particular ice algae? • location of ice algae in ice the fate of DMS (air/water?) • regulating environmental factors
SAMPLING ICE DRILLING ice depth temperature nutrients (tot-N, tot-P, diss-Si) chl-a organisms photo: J. Paatero, FMI
PROCESSING & ANALYSIS • FSW melted ice cores organisms: species id, abundance, photo-/heterotrophy • melted ice cores bulk salinity, tot-P, tot-N, diss-Si, chl-a
BRINE SALINITY brine salinity ice depth (cm)
BRINE VOLUME % of total ice volume ice depth (cm)
NUTRIENTSdrift 4 ice depth (cm) µg/l
NUTRIENTSdrift 7 ice depth (cm) µg/l
ORGANISMS DIATOMS, photo- and heterotrophic flagellates, ciliates, resting stages...
COMPARISONS CHL-A • WATER 0.1-0.5 µg/1000 mlintegr. 3-5 µg/1000 ml • ICE 0.1- ~13 µg/1000 mlintegr. 3-5 µg/1000 ml • MARGINAL ICE ZONE (MIZ) integr. ~150 µg/1000 ml
QUICK CONCLUSIONS • ”typical” arctic summer ice: melting on top, intact interior, seawater impact at the bottom • low N:P ratios most nutrients in particulate form • diatoms dominating DMS production in ice • organisms in the interior/bottom of ice layer • most DMS production through water, in particular in the MIZ
THANKS TO • Swedish Polar Secretariat • Swedish Maritime Administration & crew onboard IB ”Oden” • Nordic Arctic Research Programme (NARP) • Profs. Caroline Leck & Lars Tranvik (Sweden) & Paul Wassmann (Norway) • Tvärminne Zoological Station, Univ. of Helsinki, Finland • Drs. Jussi Paatero (Finland) & Zoë Fleming (GB)