Ice-algal aggregates

The data associated with this entry have been obtained while working on a drift ice station occupied from 26 July to 3 August 2012 and initially situated at 82.5° N, 21° E north of Svalbard during the Centre for Ice, Climate and Ecosystem (ICE) cruise (22 July - 07 August 2012). The data set include...

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Bibliographic Details
Main Authors: Assmy, Philipp, Fernández-Méndez, Mar, Daase, Malin, Renner, Angelika H.H., Spreen, Gunnar, Granskog, Mats A., Hudson, Stephen R., Fransson, Agneta, Sundfjord, Arild, Hop, Haakon
Format: Dataset
Language:unknown
Published: npolar.no 2013
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Online Access:https://dx.doi.org/10.21334/npolar.2013.67eede8a
https://data.npolar.no/dataset/67eede8a-fe8f-11e2-ba11-005056ad0004
Description
Summary:The data associated with this entry have been obtained while working on a drift ice station occupied from 26 July to 3 August 2012 and initially situated at 82.5° N, 21° E north of Svalbard during the Centre for Ice, Climate and Ecosystem (ICE) cruise (22 July - 07 August 2012). The data set includes the following variables: chlrophyll a, particulate organic carbon and nitrogen, biomass estimates of ice algal aggregates, and species composition of ice algal aggregates. The main scientific findings are summarized below. During two consecutive cruises to the Eastern Central Arctic in late summer 2012, we observed floating algal aggregates in the melt-water layer below and between melting ice floes of first-year pack ice. The macroscopic (1-15 cm in diameter) aggregates had a mucous consistency and were dominated by typical ice-associated pennate diatoms embedded within the mucous matrix. Aggregates maintained buoyancy and accumulated just above a strong pycnocline that separated meltwater and seawater layers. We were able, for the first time, to obtain quantitative abundance and biomass estimates of these aggregates. Although their biomass and production on a square metre basis was small compared to ice-algal blooms, the floating ice-algal aggregates supported high levels of biological activity on the scale of the individual aggregate. In addition they constituted a food source for the ice-associated fauna as revealed by pigments indicative of zooplankton grazing, high abundance of naked ciliates, and ice amphipods associated with them. During the Arctic melt season, these floating aggregates likely play an important ecological role in an otherwise impoverished near-surface sea ice environment. Our findings provide important observations and measurements of a unique aggregate-based habitat during the 2012 record sea ice minimum year.