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author Cuny, Philippe
Marty, Jean-Claude
Chiavérini, Jacques
Vescovali, Isabelle
Raphel, Danielle
Rontani, Jean-François
author_facet Cuny, Philippe
Marty, Jean-Claude
Chiavérini, Jacques
Vescovali, Isabelle
Raphel, Danielle
Rontani, Jean-François
collection Datos científicos de ciencias marinas y ambientales
contents Particulate samples from the water column were collected monthly from depths of 5-150 m, between May 1996 and March 1997, in the northwestern Mediterranean Sea (Ligurian Sea) as part of the DYFAMED project within the French JGOFS program. These samples were analyzed by gas chromatography-electron impact mass spectrometry for their phytol and 3-methylidene-3,7,11-trimethylhexadecan-1,2-diol (phytyldiol) content. The corresponding Chlorophyll Phytyl side chain Photodegradation Index, molar ratio of phytyldiol to phytol, was calculated and the mean amount of chlorophyll photodegraded within the euphotic zone estimated. Seasonal differences in the chlorophyll photodegradation process appear in the one-year study. The chlorophyll appeared more photodegraded in the surface water (generally more than 40% photodegraded at 5-10 m) than at the deep chlorophyll maximum (DCM) (40-50 m) observed in the summer stratified waters (about 20% photodegraded). This difference was attributed to the healthy state of the phytoplankton community (coincidence with the highest primary production levels) and to the lower intensity of irradiance at the DCM level. On the other hand, the bulk of the detrital chlorophyll (chlorophyll associated with phytodetritus, phaeopigments) undergoes photodegradation before it sinks out of the photic zone. However, in January (winter mixed water) the pigments exported towards the sea floor were less photodegraded. This is thought to result from a shorter period of residence of the pigments in the photic zone due to vertical convection and grazing activity of macrozooplankton (salps), which are producers of rapid sinking fecal pellets.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_738645
institution PANGAEA
language en
publishDate 2002
publisher PANGAEA
record_format pangaea
spellingShingle Phytol and phytyldiol concentrations at DYFAMED time series station and sediment trap
Cuny, Philippe
Marty, Jean-Claude
Chiavérini, Jacques
Vescovali, Isabelle
Raphel, Danielle
Rontani, Jean-François
Biogeochemical Processes in the Oceans and Fluxes; CTD/Rosette; CTD-RO; DYF10; DYFAMED__Campaign; DYFAMED_19990614; DYFAMED_D011096D; DYFAMED_D020397D; DYFAMED_D031296D; DYFAMED_D100796D; DYFAMED_D130197D; DYFAMED_D230297D; DYFAMED_D230596D; DYFAMED_D250896D; JGOFS; Joint Global Ocean Flux Study; MEDAR/MEDATLAS; Mediterranean Data Archaeology and Rescue; PROOF; SESAME; Southern European Seas: Assessing and Modelling Ecosystem Changes; Time-series station; Trap; TRAP
Particulate samples from the water column were collected monthly from depths of 5-150 m, between May 1996 and March 1997, in the northwestern Mediterranean Sea (Ligurian Sea) as part of the DYFAMED project within the French JGOFS program. These samples were analyzed by gas chromatography-electron impact mass spectrometry for their phytol and 3-methylidene-3,7,11-trimethylhexadecan-1,2-diol (phytyldiol) content. The corresponding Chlorophyll Phytyl side chain Photodegradation Index, molar ratio of phytyldiol to phytol, was calculated and the mean amount of chlorophyll photodegraded within the euphotic zone estimated. Seasonal differences in the chlorophyll photodegradation process appear in the one-year study. The chlorophyll appeared more photodegraded in the surface water (generally more than 40% photodegraded at 5-10 m) than at the deep chlorophyll maximum (DCM) (40-50 m) observed in the summer stratified waters (about 20% photodegraded). This difference was attributed to the healthy state of the phytoplankton community (coincidence with the highest primary production levels) and to the lower intensity of irradiance at the DCM level. On the other hand, the bulk of the detrital chlorophyll (chlorophyll associated with phytodetritus, phaeopigments) undergoes photodegradation before it sinks out of the photic zone. However, in January (winter mixed water) the pigments exported towards the sea floor were less photodegraded. This is thought to result from a shorter period of residence of the pigments in the photic zone due to vertical convection and grazing activity of macrozooplankton (salps), which are producers of rapid sinking fecal pellets.
title Phytol and phytyldiol concentrations at DYFAMED time series station and sediment trap
topic Biogeochemical Processes in the Oceans and Fluxes; CTD/Rosette; CTD-RO; DYF10; DYFAMED__Campaign; DYFAMED_19990614; DYFAMED_D011096D; DYFAMED_D020397D; DYFAMED_D031296D; DYFAMED_D100796D; DYFAMED_D130197D; DYFAMED_D230297D; DYFAMED_D230596D; DYFAMED_D250896D; JGOFS; Joint Global Ocean Flux Study; MEDAR/MEDATLAS; Mediterranean Data Archaeology and Rescue; PROOF; SESAME; Southern European Seas: Assessing and Modelling Ecosystem Changes; Time-series station; Trap; TRAP
url https://doi.org/10.1594/PANGAEA.738645