The University of Southampton
University of Southampton Institutional Repository

Relative influence of nitrogen and phosphorous availability on phytoplankton physiology and productivity in the oligotrophic sub-tropical North Atlantic Ocean

Relative influence of nitrogen and phosphorous availability on phytoplankton physiology and productivity in the oligotrophic sub-tropical North Atlantic Ocean
Relative influence of nitrogen and phosphorous availability on phytoplankton physiology and productivity in the oligotrophic sub-tropical North Atlantic Ocean
Nutrient addition bioassay experiments were performed in the low-nutrient, low-chlorophyll oligotrophic subtropical North Atlantic Ocean to investigate the influence of nitrogen (N), phosphorus (P), and/or iron (Fe) on phytoplankton physiology and the limitation of primary productivity or picophytoplankton biomass. Additions of N alone resulted in 1.5–2 fold increases in primary productivity and chlorophyll after 48 h, with larger (~threefold) increases observed for the addition of P in combination with N (NP). Measurements of cellular chlorophyll contents permitted evaluation of the physiological response of the photosynthetic apparatus to N and P additions in three picophytoplankton groups. In both Prochlorococcus and the picoeukaryotes, cellular chlorophyll increased by similar amounts in N and NP treatments relative to all other treatments, suggesting that pigment synthesis was N limited. In contrast, the increase of cellular chlorophyll was greater in NP than in N treatments in Synechococcus, suggestive of NP co-limitation. Relative increases in cellular nucleic acid were also only observed in Synechococcus for NP treatments, indicating co-limitation of net nucleic acid synthesis. A lack of response to relief of nutrient stress for the efficiency of photosystem II photochemistry, Fv :Fm, suggests that the low nutrient supply to this region resulted in a condition of balanced nutrient limited growth, rather than starvation. N thus appears to be the proximal (i.e. direct physiological) limiting nutrient in the oligotrophic sub-tropical North Atlantic. In addition, some major picophytoplankton groups, as well as overall autotrophic community biomass, appears to be co-limited by N and P.
0024-3590
291-305
Moore, C.M.
7ec80b7b-bedc-4dd5-8924-0f5d01927b12
Mills, M.M.
8e317c31-d48d-48a2-85b3-de0871d01f36
Langlois, R.
9344b63c-4e7a-48c0-8e79-7cb8b742af2c
Milne, A.
e496b797-6206-414e-8f50-d2f2ce260fc9
Achterberg, E.P.
685ce961-8c45-4503-9f03-50f6561202b9
La Roche, J.
a2c0a07e-b1c8-421b-ace6-885b3d107e02
Geider, R.J.
1a7a44c1-0468-4eba-920a-28420f6f7273
Moore, C.M.
7ec80b7b-bedc-4dd5-8924-0f5d01927b12
Mills, M.M.
8e317c31-d48d-48a2-85b3-de0871d01f36
Langlois, R.
9344b63c-4e7a-48c0-8e79-7cb8b742af2c
Milne, A.
e496b797-6206-414e-8f50-d2f2ce260fc9
Achterberg, E.P.
685ce961-8c45-4503-9f03-50f6561202b9
La Roche, J.
a2c0a07e-b1c8-421b-ace6-885b3d107e02
Geider, R.J.
1a7a44c1-0468-4eba-920a-28420f6f7273

Moore, C.M., Mills, M.M., Langlois, R., Milne, A., Achterberg, E.P., La Roche, J. and Geider, R.J. (2008) Relative influence of nitrogen and phosphorous availability on phytoplankton physiology and productivity in the oligotrophic sub-tropical North Atlantic Ocean. Limnology and Oceanography, 53 (1), 291-305. (doi:10.4319/lo.2008.53.1.0291).

Record type: Article

Abstract

Nutrient addition bioassay experiments were performed in the low-nutrient, low-chlorophyll oligotrophic subtropical North Atlantic Ocean to investigate the influence of nitrogen (N), phosphorus (P), and/or iron (Fe) on phytoplankton physiology and the limitation of primary productivity or picophytoplankton biomass. Additions of N alone resulted in 1.5–2 fold increases in primary productivity and chlorophyll after 48 h, with larger (~threefold) increases observed for the addition of P in combination with N (NP). Measurements of cellular chlorophyll contents permitted evaluation of the physiological response of the photosynthetic apparatus to N and P additions in three picophytoplankton groups. In both Prochlorococcus and the picoeukaryotes, cellular chlorophyll increased by similar amounts in N and NP treatments relative to all other treatments, suggesting that pigment synthesis was N limited. In contrast, the increase of cellular chlorophyll was greater in NP than in N treatments in Synechococcus, suggestive of NP co-limitation. Relative increases in cellular nucleic acid were also only observed in Synechococcus for NP treatments, indicating co-limitation of net nucleic acid synthesis. A lack of response to relief of nutrient stress for the efficiency of photosystem II photochemistry, Fv :Fm, suggests that the low nutrient supply to this region resulted in a condition of balanced nutrient limited growth, rather than starvation. N thus appears to be the proximal (i.e. direct physiological) limiting nutrient in the oligotrophic sub-tropical North Atlantic. In addition, some major picophytoplankton groups, as well as overall autotrophic community biomass, appears to be co-limited by N and P.

This record has no associated files available for download.

More information

Published date: January 2008
Organisations: Ocean and Earth Science

Identifiers

Local EPrints ID: 50107
URI: http://eprints.soton.ac.uk/id/eprint/50107
ISSN: 0024-3590
PURE UUID: bba6fb0b-1beb-473f-b78d-cded8d4bb94f
ORCID for C.M. Moore: ORCID iD orcid.org/0000-0002-9541-6046

Catalogue record

Date deposited: 25 Jan 2008
Last modified: 09 Jan 2022 03:01

Export record

Altmetrics

Contributors

Author: C.M. Moore ORCID iD
Author: M.M. Mills
Author: R. Langlois
Author: A. Milne
Author: E.P. Achterberg
Author: J. La Roche
Author: R.J. Geider

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×