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| Titel |
Particle aggregation at the edges of anticyclonic eddies and implications for distribution of biomass |
| VerfasserIn |
A. Samuelsen, S. S. Hjøllo, J. A. Johannessen, R. Patel |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1812-0784
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| Digitales Dokument |
URL |
| Erschienen |
In: Ocean Science ; 8, no. 3 ; Nr. 8, no. 3 (2012-06-14), S.389-400 |
| Datensatznummer |
250005632
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| Publikation (Nr.) |
 copernicus.org/os-8-389-2012.pdf |
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| Zusammenfassung |
| Acoustic measurements show that the biomass of zooplankton and mesopelagic
fish is redistributed by mesoscale variability and that the signal extends
over several hundred meters depth. The mechanisms governing this
distribution are not well understood, but influences from both physical
(i.e. redistribution) and biological processes (i.e. nutrient transport,
primary production, active swimming, etc.) are likely. This study examines
how hydrodynamic conditions and basic vertical swimming behavior act to
distribute biomass in an anticyclonic eddy. Using an eddy-resolving 2.3 km-resolution physical ocean model as forcing for a particle-tracking
module, particles representing passively floating organisms and organisms
with vertical swimming behavior are released within an eddy and monitored
for 20 to 30 days. The role of hydrodynamic conditions on the distribution
of biomass is discussed in relation to the acoustic measurements. Particles
released close to the surface tend, in agreement with the observations, to
accumulate around the edge of the eddy, whereas particles released at depth
gradually become distributed along the isopycnals. After a month they are
displaced several hundreds meters in the vertical with the deepest particles
found close to the eddy center and the shallowest close to the edge. There
is no evidence of aggregation of particles along the eddy rim in the last
simulation. The model results points towards a physical mechanism for
aggregation at the surface, however biological processes cannot be ruled out
using the current modeling tool. |
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