Publication Date:
2023-10-28
Description:
During two expeditions of the R.V. “Polarstern” to the Arctic Ocean, pack ice and under-ice water samples were collected during two different seasons: late summer (September 2002) and late winter (March/April 2003). Physical and biological properties of the ice were investigated to explain seasonal differences in species composition, abundance and distribution patterns of sympagic meiofauna (in this case: heterotrophs 〉20 µm). In winter, the ice near the surface was characterized by extreme physical conditions (minimum ice temperature: -22°C, maximum brine salinity: 223, brine volume: 〈=5%) and more moderate conditions in summer (minimum ice temperature: -5.6°C, maximum brine salinity: 94, most brine volumes: 〉=5%). Conditions in the lowermost part of the ice did not differ to a high degree between summer and winter. Chlorophyll a concentrations (chl a) showed significant differences between summer and winter: during winter, concentrations were mostly 〈1.0 µg chl a/l, while chl a concentrations of up to 67.4 µmol/l were measured during summer. The median of depth-integrated chl a concentration in summer was significantly higher than in winter. Integrated abundances of sympagic meiofauna were within the same range for both seasons and varied between 0.6 and 34.1×103 organisms /m**2 in summer and between 3.7 and 24.8×10**3 organisms /m**2 in winter. With regard to species composition, a comparison between the two seasons showed distinct differences: while copepods (42.7%) and rotifers (33.4%) were the most abundant sea-ice meiofaunal taxa during summer, copepod nauplii dominated the community, comprising 92.9% of the fauna, in winter. Low species abundances were found in the under-ice water, indicating that overwintering of the other sympagic organisms did not take place there, either. Therefore, their survival strategy over the polar winter remains unclear.
Keywords:
Arctic Ocean; ARK-XIX/1; ARK-XVIII/2; Barents Sea; Date/Time of event; Elevation of event; Event label; ICE; Ice coverage; Ice station; Latitude of event; Longitude of event; MULT; Multiple investigations; North Greenland Sea; Number; Polarstern; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; PS62; PS62/300-1; PS62/302-1; PS62/312-1; PS62/313-1; PS62/315-1; PS64; PS64/028-1; PS64/039-1; PS64/070-6; PS64/093-1; PS64/111-3; Sampling date; Sea ice thickness; Snow thickness; SPP1158; Temperature, air; Temperature, ice/snow
Type:
Dataset
Format:
text/tab-separated-values, 68 data points
Permalink
