The role of transparent exopolymer particles (TEP) in the increase in apparent particle stickiness (alpha) during the decline of a diatom bloom.

Engel, Anja (2000) The role of transparent exopolymer particles (TEP) in the increase in apparent particle stickiness (alpha) during the decline of a diatom bloom. Journal of Plankton Research, 22 (3). pp. 485-497. DOI 10.1093/plankt/22.3.485.

[img] Text
485.full.pdf - Published Version
Restricted to Registered users only

Download (95Kb) | Contact

Supplementary data:

Abstract

The termination of diatom spring blooms in temperate waters has been connected with the formation and subsequent rapid sedimentation of aggregates. According to coagulation theory, the rate of aggregate formation depends on the probability of particle collision and on the efficiency with which two particles adhere once they have collided (stickiness). During this study, the variation in particle stickiness was determined over the decline of a diatom bloom using the Couette Chamber assay with low shear (G = 0.86 s–1). A mixed diatom population, dominated by Skeletonema costatum, was sampled during the spring bloom in the Baltic Sea and incubated in the laboratory for 18 days. Measurements of diatom species composition, transparent exopolymer particles (TEP) and bulk particle abundance, as well as chemical and biological variables, were conducted in order to reveal the determinants of coagulation efficiency. The investigation showed that an increase in TEP concentration relative to conventional particles at the decline of the bloom significantly enhanced apparent coagulation efficiencies. High proportions of TEP led to apparent values of stickiness >1, which indicates that collision rates can be substantially underestimated when the stickiness parameter α is calculated on the basis of conventional particle counting only, e.g. with the Coulter Counter. A new stickiness parameter, α′, was therefore estimated based on the combined volume fractions of TEP and conventional particles. The problems of stickiness measurements are discussed and the role of TEP in coagulation processes is emphasized.

Document Type: Article
Keywords: Marine Biology; TEP; Transparent Exopolymer particles
Research affiliation: OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-BI Biological Oceanography
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1093/plankt/22.3.485
ISSN: 0142-7873
Date Deposited: 30 Sep 2011 09:04
Last Modified: 30 May 2018 12:39
URI: http://oceanrep.geomar.de/id/eprint/12244

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...