Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand

The Subantarctic zone is one of the largest High-Nutrient Low-Chlorophyll zones of the Southern Ocean. Despite widespread iron limitation, phytoplankton accumulation (chlorophyll a (chla) > 0.3 mg m−3) often occurs near islands and bathymetric features such as on the Campbell Plateau, southeast o...

Full description

Bibliographic Details
Authors: Gutiérrez-Rodríguez, A., Safi, K., Moret-Fernández, David, Forcén-Vázquez, A., Gourvil, P., Hoffmann, L., Pinkerton, Matthew H., Sutton, P., Nodder, S. D.
Format: article
Status:Versión enviada para evaluación y publicación
Publication Date:2020
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/379098
Online Access:http://hdl.handle.net/10261/379098
https://api.elsevier.com/content/abstract/scopus_id/85085574970
Access Level:Open access
Keyword:growth rate | microzooplankton grazing | mixed-layer depth | phytoplankton | primary production | southern ocean
id ES_dea708aafea8e11bb2aa775e213f6d2c
oai_identifier_str oai:digital.csic.es:10261/379098
network_acronym_str ES
network_name_str España
repository_id_str
spelling Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New ZealandGutiérrez-Rodríguez, A.Safi, K.Moret-Fernández, DavidForcén-Vázquez, A.Gourvil, P.Hoffmann, L.Pinkerton, Matthew H.Sutton, P.Nodder, S. D.growth rate | microzooplankton grazing | mixed-layer depth | phytoplankton | primary production | southern oceanThe Subantarctic zone is one of the largest High-Nutrient Low-Chlorophyll zones of the Southern Ocean. Despite widespread iron limitation, phytoplankton accumulation (chlorophyll a (chla) > 0.3 mg m−3) often occurs near islands and bathymetric features such as on the Campbell Plateau, southeast of New Zealand. To investigate the processes responsible for localized increases in chla commonly observed by satellites, we characterized phytoplankton biomass structure, production, and microzooplankton grazing on Campbell Plateau and surrounding waters in austral autumn (March 2017). Chla on the plateau tended to be higher, more variable (0.52 ± 0.38 mg chla m−3, mean ± standard deviation), and characterized by larger phytoplankton forms (22 ± 27%chla > 20 μm) than surrounding waters (0.29 ± 0.12 mg chla m−3, 5 ± 2%). The increased contribution of diatoms, together with higher photosystem II maximum photochemical efficiency (Fv/Fm = 0.45 ± 0.05) and lower effective absorption cross-section (σPSII = 774 ± 90 Å RCII−1) on the plateau, suggests an alleviation of iron stress relative to surrounding waters (Fv/Fm = 0.37 ± 0.04, σPSII = 974 ± 89 Å RCII−1). Phytoplankton growth (μ0 = 0.42 ± 0.20 day−1) and production rates (6.1 ± 3.2 mg C m−3 day−1) were also higher compared to surrounding waters (0.27 ± 0.04 day−1, 3.5 ± 1.9 mg C m−3 day−1). While microzooplankton grazing (g = 0.28 ± 0.18 day−1) balanced phytoplankton growth off the plateau (g:μ0 = 1.13 ± 0.18), the imbalance observed on Campbell Plateau (g = 0.25 ± 0.25 day−1) allowed a substantial proportion of primary production to escape microzooplankton grazing control (g:μ0 = 0.48 ± 0.31). Overall, the degree of coupling tended to decrease with the depth of the mixed layer (R2 > 0.6, p < 0.001). We hypothesize that the entrainment of deeper water into the mixed layer regulates the onset and fate of the autumn bloom by altering nutrient supply and microzooplankton grazing pressure.Peer reviewedJohn Wiley & SonsGutiérrez-Rodríguez, A. [0000-0003-1274-3752]Safi, K. [0000-0002-7785-1909]Moret-Fernández, David [0000-0002-8192-9537]Gourvil, P. [0000-0003-0408-4988]Sutton, P. [0000-0003-2936-0918]Nodder, S. D. [0000-0002-1963-8907]202520252020info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Preprintinfo:eu-repo/semantics/submittedVersionhttp://hdl.handle.net/10261/379098https://api.elsevier.com/content/abstract/scopus_id/85085574970reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)InglésJournal of Geophysical Research: Oceanshttps://doi.org/10.1029/2019JC015550Noinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/3790982026-05-22T06:33:51Z
dc.title.none.fl_str_mv Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand
title Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand
spellingShingle Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand
Gutiérrez-Rodríguez, A.
growth rate | microzooplankton grazing | mixed-layer depth | phytoplankton | primary production | southern ocean
title_short Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand
title_full Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand
title_fullStr Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand
title_full_unstemmed Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand
title_sort Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand
dc.creator.none.fl_str_mv Gutiérrez-Rodríguez, A.
Safi, K.
Moret-Fernández, David
Forcén-Vázquez, A.
Gourvil, P.
Hoffmann, L.
Pinkerton, Matthew H.
Sutton, P.
Nodder, S. D.
author Gutiérrez-Rodríguez, A.
author_facet Gutiérrez-Rodríguez, A.
Safi, K.
Moret-Fernández, David
Forcén-Vázquez, A.
Gourvil, P.
Hoffmann, L.
Pinkerton, Matthew H.
Sutton, P.
Nodder, S. D.
author_role author
author2 Safi, K.
Moret-Fernández, David
Forcén-Vázquez, A.
Gourvil, P.
Hoffmann, L.
Pinkerton, Matthew H.
Sutton, P.
Nodder, S. D.
author2_role author
author
author
author
author
author
author
author
dc.contributor.none.fl_str_mv Gutiérrez-Rodríguez, A. [0000-0003-1274-3752]
Safi, K. [0000-0002-7785-1909]
Moret-Fernández, David [0000-0002-8192-9537]
Gourvil, P. [0000-0003-0408-4988]
Sutton, P. [0000-0003-2936-0918]
Nodder, S. D. [0000-0002-1963-8907]
dc.subject.none.fl_str_mv growth rate | microzooplankton grazing | mixed-layer depth | phytoplankton | primary production | southern ocean
topic growth rate | microzooplankton grazing | mixed-layer depth | phytoplankton | primary production | southern ocean
description The Subantarctic zone is one of the largest High-Nutrient Low-Chlorophyll zones of the Southern Ocean. Despite widespread iron limitation, phytoplankton accumulation (chlorophyll a (chla) > 0.3 mg m−3) often occurs near islands and bathymetric features such as on the Campbell Plateau, southeast of New Zealand. To investigate the processes responsible for localized increases in chla commonly observed by satellites, we characterized phytoplankton biomass structure, production, and microzooplankton grazing on Campbell Plateau and surrounding waters in austral autumn (March 2017). Chla on the plateau tended to be higher, more variable (0.52 ± 0.38 mg chla m−3, mean ± standard deviation), and characterized by larger phytoplankton forms (22 ± 27%chla > 20 μm) than surrounding waters (0.29 ± 0.12 mg chla m−3, 5 ± 2%). The increased contribution of diatoms, together with higher photosystem II maximum photochemical efficiency (Fv/Fm = 0.45 ± 0.05) and lower effective absorption cross-section (σPSII = 774 ± 90 Å RCII−1) on the plateau, suggests an alleviation of iron stress relative to surrounding waters (Fv/Fm = 0.37 ± 0.04, σPSII = 974 ± 89 Å RCII−1). Phytoplankton growth (μ0 = 0.42 ± 0.20 day−1) and production rates (6.1 ± 3.2 mg C m−3 day−1) were also higher compared to surrounding waters (0.27 ± 0.04 day−1, 3.5 ± 1.9 mg C m−3 day−1). While microzooplankton grazing (g = 0.28 ± 0.18 day−1) balanced phytoplankton growth off the plateau (g:μ0 = 1.13 ± 0.18), the imbalance observed on Campbell Plateau (g = 0.25 ± 0.25 day−1) allowed a substantial proportion of primary production to escape microzooplankton grazing control (g:μ0 = 0.48 ± 0.31). Overall, the degree of coupling tended to decrease with the depth of the mixed layer (R2 > 0.6, p < 0.001). We hypothesize that the entrainment of deeper water into the mixed layer regulates the onset and fate of the autumn bloom by altering nutrient supply and microzooplankton grazing pressure.
publishDate 2020
dc.date.none.fl_str_mv 2020
2025
2025
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
Preprint
info:eu-repo/semantics/submittedVersion
format article
status_str submittedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/379098
https://api.elsevier.com/content/abstract/scopus_id/85085574970
url http://hdl.handle.net/10261/379098
https://api.elsevier.com/content/abstract/scopus_id/85085574970
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Journal of Geophysical Research: Oceans
https://doi.org/10.1029/2019JC015550
No
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv John Wiley & Sons
publisher.none.fl_str_mv John Wiley & Sons
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869421993228500992
score 15,811543

Similar Items