Chlorophyll in Copepod Faecal Pellets: Changes in Pellet Numbers and Pigment Content during a Declining Baltic Spring Bloom |
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Authors: | Ulrich Bathmann Gerd Liebezeit |
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Institution: | Institut für Meereskunde, Diisternbrooker Weg 20, D-2300 Kiel, FRG. |
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Abstract: | Abstract. Zooplankton stock as well as faecal pellet numbers were monitored over 2 weeks during May in the central Baltic. Considerable changes in concentrations of chlorophyll and its derivates in copepod faecal pellets as well as in surface sediments were found during this period. The maximum concentration of 1.05 ngchl. a faecal pellet-1, measured on 12 May, decreased by the end of the month to 0.08 ngchl. a faecal pellet-1. This decrease was positively correlated with the disappearance of intact diatoms inside faeces. A flux of 1.53mgchl. a -m-2-day-1 via faecal pellets was calculated for the deep water layer (60–80 m) in mid May. This decreased to 0.005mgchl. a m-2 day-1 by the end of May. Chi. a accounted for up to 10 % of total pigments in samples from the top centimetre of the sediment surface. The means of transportation of faecal pellets as well as their function as a food supply to deeper ecosystems are discussed. |
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Keywords: | Faecal pellets HPLC chlorophyll pigments sedimentary pigments SEM |
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