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Spatial variability in the coupling of organic carbon, nutrients, and phytoplankton pigments in surface waters and sediments of the Mississippi River plume

Wysocki, Laura A. ; Bianchi, Thomas S. ; Powell, Rodney T. and Reuss, Nina LU (2006) In Estuarine, Coastal and Shelf Science 69(1-2). p.47-63
Abstract
River-dominated coastal areas are typically sites of active biogeochemical cycling, with productivity enhanced by terrestrial inputs of nutrients and organic matter. To examine the spatial variability and relationship between river discharge, phytoplankton, and organic carbon distributions, we analyzed surface water and sediment from the Louisiana shelf adjacent to the Mississippi River. Samples were collected during April and October 2000 to capture high and low river discharge, and were analyzed for dissolved and particulate organic carbon (DOC and POC), nutrients, and phytoplankton pigments. Pigments, determined by high performance liquid chromatography (HPLC), were also analyzed from sediment to evaluate marine carbon inputs to the... (More)
River-dominated coastal areas are typically sites of active biogeochemical cycling, with productivity enhanced by terrestrial inputs of nutrients and organic matter. To examine the spatial variability and relationship between river discharge, phytoplankton, and organic carbon distributions, we analyzed surface water and sediment from the Louisiana shelf adjacent to the Mississippi River. Samples were collected during April and October 2000 to capture high and low river discharge, and were analyzed for dissolved and particulate organic carbon (DOC and POC), nutrients, and phytoplankton pigments. Pigments, determined by high performance liquid chromatography (HPLC), were also analyzed from sediment to evaluate marine carbon inputs to the seafloor. DOC in surface waters was generally within 200-300 mu M, ranging up to 399 mu M. Chlorophyll a ranged from below the limits of detection (BLD) up to 31 nM in surface waters, with higher values located further from the river mouth during high flow. Although community diversity increased during low discharge, diatoms dominated the phytoplankton population (50-80% of the community throughout the study) and consequently made more important contributions than other species to both the DOC and POC pools. Chlorophyll and degradation products (indicative of zooplankton grazing) observed in surface sediment indicated a transfer of autochthonous carbon from the highly productive photic zone to the sediment, coupling phytoplankton-derived POC in surface waters with organic carbon deposition in surface sediment. Cross-shelf changes in chlorophyll indicated a westward transport of phytoplankton that was directly and indirectly linked with river discharge and pigment decay dynamics. (c) 2006 Elsevier Ltd. All rights reserved. (Less)
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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Mississippi River plume, pigment biomarkers, phytoplankton, organic matter, benthic-pelagic, coupling, Gulf of Mexico
in
Estuarine, Coastal and Shelf Science
volume
69
issue
1-2
pages
47 - 63
publisher
Elsevier
external identifiers
  • wos:000239855300005
  • scopus:33745918622
ISSN
1096-0015
DOI
10.1016/j.ecss.2006.03.022
language
English
LU publication?
yes
id
3afec5fa-a49c-4d03-beeb-7600d0ea4e7e (old id 397467)
date added to LUP
2016-04-01 11:52:00
date last changed
2021-10-06 04:12:10
@article{3afec5fa-a49c-4d03-beeb-7600d0ea4e7e,
  abstract     = {River-dominated coastal areas are typically sites of active biogeochemical cycling, with productivity enhanced by terrestrial inputs of nutrients and organic matter. To examine the spatial variability and relationship between river discharge, phytoplankton, and organic carbon distributions, we analyzed surface water and sediment from the Louisiana shelf adjacent to the Mississippi River. Samples were collected during April and October 2000 to capture high and low river discharge, and were analyzed for dissolved and particulate organic carbon (DOC and POC), nutrients, and phytoplankton pigments. Pigments, determined by high performance liquid chromatography (HPLC), were also analyzed from sediment to evaluate marine carbon inputs to the seafloor. DOC in surface waters was generally within 200-300 mu M, ranging up to 399 mu M. Chlorophyll a ranged from below the limits of detection (BLD) up to 31 nM in surface waters, with higher values located further from the river mouth during high flow. Although community diversity increased during low discharge, diatoms dominated the phytoplankton population (50-80% of the community throughout the study) and consequently made more important contributions than other species to both the DOC and POC pools. Chlorophyll and degradation products (indicative of zooplankton grazing) observed in surface sediment indicated a transfer of autochthonous carbon from the highly productive photic zone to the sediment, coupling phytoplankton-derived POC in surface waters with organic carbon deposition in surface sediment. Cross-shelf changes in chlorophyll indicated a westward transport of phytoplankton that was directly and indirectly linked with river discharge and pigment decay dynamics. (c) 2006 Elsevier Ltd. All rights reserved.},
  author       = {Wysocki, Laura A. and Bianchi, Thomas S. and Powell, Rodney T. and Reuss, Nina},
  issn         = {1096-0015},
  language     = {eng},
  number       = {1-2},
  pages        = {47--63},
  publisher    = {Elsevier},
  series       = {Estuarine, Coastal and Shelf Science},
  title        = {Spatial variability in the coupling of organic carbon, nutrients, and phytoplankton pigments in surface waters and sediments of the Mississippi River plume},
  url          = {http://dx.doi.org/10.1016/j.ecss.2006.03.022},
  doi          = {10.1016/j.ecss.2006.03.022},
  volume       = {69},
  year         = {2006},
}