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dc.contributor.authorFragoso, Glaucia Moreira
dc.contributor.authorDavies, Emlyn John
dc.contributor.authorEllingsen, Ingrid H.
dc.contributor.authorChauton, Matilde Skogen
dc.contributor.authorFossum, Trygve Olav
dc.contributor.authorLudvigsen, Martin
dc.contributor.authorSteinhovden, Kristine
dc.contributor.authorRajan, Kanna
dc.contributor.authorJohnsen, Geir
dc.identifier.citationProgress in Oceanography. 2019, 175 284-299.en_US
dc.description.abstractThe impact of the physical environment and phytoplankton size on particle types (zooplankton, biogenic matter or phytodetritus) in the water column is poorly understood. Here, we investigate how hydrography (e.g. water column stratification) impacts phytoplankton size and photophysiology across a productive coastal bank area. Additionally, we investigate how the physical environment and phytoplankton size structure influence the concentrations of plankton (e.g. copepods and diatom chains), biogenic forms (fecal pellets) and other particles (minerals, aggregates or phytodetritus) using discrete samples and in-situ optical instruments. Microphytoplankton (>20 µm), including many chain-forming diatoms, dominated (average > 90% of total size fraction) in un-stratified waters of the bank. Phytoplankton within the bank region also required more irradiance to saturate photosynthesis, as indicated by the onset light saturation parameter (Ek, average 297 µmol photons m−2 s−1), suggesting high plasticity to a dynamic light environment. Conversely, the contribution of nano- and picophytoplankton (<20 µm), such as flagellates increased (up to 36% of total phytoplankton size fraction) towards stratified off-bank waters. The phytoplankton community from off-bank had lower Ek (average 199 µmol photons m−2 s−1) and presented higher concentrations of photoprotective pigments, such diatoxanthin – used in the xanthophyll cycle to cope with light stress and potential photo-damage. Higher concentrations of copepods (>1 × 103 counts m−3), fecal pellets (>1 × 104 counts m−3) and ammonium (>0.5 µM) within the bank compared to off-bank regions, indicated that copepods were actively grazing in this region. Low stratification (average stratification index (SI) < 6 × 10−3 kg m−4) allowed for intensive mixing, which might have promoted the high concentration of aggregates (>5 × 105 counts m−3) within the bank when compared to off-bank (SI off-bank > 10 × 10−3 kg m−4). Our results, obtained using automated techniques measured in-situ, represent an innovative approach to demonstrate that phytoplankton size and stratification influence the nature of particles found in the water column (including aggregates, fecal pellets and grazer abundances).en_US
dc.rightsAttribution-NonCommercial-NoDerivatives 4.0 Internasjonal*
dc.titlePhysical controls on phytoplankton size structure, photophysiology and suspended particles in a Norwegian biological hotspoten_US
dc.typePeer revieweden_US
dc.typeJournal articleen_US
dc.source.journalProgress in Oceanographyen_US
dc.relation.projectNorges forskningsråd: 255303en_US
dc.relation.projectNorges forskningsråd: 223254en_US
dc.description.localcode© 2019. This is the authors’ accepted and refereed manuscript to the article. Locked until 8.5.2021 due to copyright restrictions. This manuscript version is made available under the CC-BY-NC-ND 4.0 license
cristin.unitnameInstitutt for biologi
cristin.unitnameInstitutt for marin teknikk
cristin.unitnameInstitutt for teknisk kybernetikk

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Attribution-NonCommercial-NoDerivatives 4.0 Internasjonal
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivatives 4.0 Internasjonal