Over het archief
Het OWA, het open archief van het Waterbouwkundig Laboratorium heeft tot doel alle vrij toegankelijke onderzoeksresultaten van dit instituut in digitale vorm aan te bieden. Op die manier wil het de zichtbaarheid, verspreiding en gebruik van deze onderzoeksresultaten, alsook de wetenschappelijke communicatie maximaal bevorderen.
Dit archief wordt uitgebouwd en beheerd volgens de principes van de Open Access Movement, en het daaruit ontstane Open Archives Initiative.
Basisinformatie over ‘Open Access to scholarly information'.
Aggregation, sedimentation and biodegradability of phytoplankton-derived material during spring in the Ross Sea, Antarctica
Becquevort, S.; Smith, W.O. (2001). Aggregation, sedimentation and biodegradability of phytoplankton-derived material during spring in the Ross Sea, Antarctica. Deep-Sea Res., Part II, Top. Stud. Oceanogr. 48(19-20): 4155-4178. dx.doi.org/10.1016/S0967-0645(01)00084-4
In: Deep-Sea Research, Part II. Topical Studies in Oceanography. Pergamon: Oxford. ISSN 0967-0645; e-ISSN 1879-0100, meer
|  |
| Auteurs | | Top |
- Becquevort, S., meer
- Smith, W.O.
|
|
|
| Abstract |
The sedimentation rates, aggregation and biodegradability of phytoplankton-derived material were investigated in the Ross Sea Polynya during austral spring, 1997. Planktonic organisms and aggregates were collected using a large volume (1001) sampler. The phytoplankton assemblages were dominated by diatoms and/or Phaeocystis antarctica, a colonial haptophyte. Total community sinking rates of phytoplankton or derived aggregates were low, ranging between 0 and 1 m d-1, except towards mid-December when the sinking rates increased to 3 m d-1. At this time, the co-occurrence of Phaeocystis colonies and diatoms resulted in the enhanced formation of aggregates. Taxon-specific differences in sinking behaviour were observed, in that diatoms and dinoflagellates had higher sinking rates than P. antarctica. The biodegradability of phytoplankton-derived material was estimated from the enzymatic (ectoprotease. ecto-beta -glucosidase) activities of free-living vs. particle-attached bacteria. Bacterial production rates were very low until late November, and from mid-December the bacterial activities increased slowly. At the same time, the proportion of attached bacteria increased; nevertheless, their contribution to the total bacterial activity remained low (less than 19% for ectoprotease, 24% for ecto-beta -glucosidase and 18% for bacterial production). In contrast, specific (per cell) activities were higher for particle-attached bacteria than for free-living bacteria. Calculations suggest that 1.4-38.5% of the primary production potentially could be removed from the euphotic zone via sinking during spring, and 0.5-11.6% could be remineralized by bacterial metabolism, with a minor contribution of particle-attached bacteria (less than 2% of the primary production). Thus, during the most active period of phytoplankton growth when grazing losses are nearly non-existent, most of the removal of phytoplankton-derived particulate material is by passive sinking, and only a small amount of the particulate organic carbon is heterotrophically oxidized. |
IMIS is ontwikkeld en wordt gehost door het VLIZ.
