Iron-limitation and high light stress on phytoplankton populations from the Australian Sub-Antarctic Zone (SAZ)
The high nutrient low chlorophyll (HNLC) surface waters of the Southern Ocean are characterised by high concentrations of nitrate and phosphate, low concentrations of dissolved iron and deep vertical mixing. Future climate scenarios predict increased surface temperatures and ocean stratification in...
Main Authors: | , , , , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
2011
|
Subjects: | |
Online Access: | http://hdl.handle.net/10453/18065 |
id |
ftunivtsydney:oai:opus.lib.uts.edu.au:10453/18065 |
---|---|
record_format |
openpolar |
spelling |
ftunivtsydney:oai:opus.lib.uts.edu.au:10453/18065 2023-05-15T13:48:10+02:00 Iron-limitation and high light stress on phytoplankton populations from the Australian Sub-Antarctic Zone (SAZ) Petrou, K Hassler, CS Doblin, MA Shelly, K Schoemann, V van den Enden, R Wright, S Ralph, PJ 2011-11-01 application/pdf http://hdl.handle.net/10453/18065 unknown Deep-Sea Research Part II: Topical Studies in Oceanography 10.1016/j.dsr2.2011.05.020 Deep-Sea Research Part II: Topical Studies in Oceanography, 2011, 58 (21-22), pp. 2200 - 2211 0967-0645 http://hdl.handle.net/10453/18065 Oceanography Journal Article 2011 ftunivtsydney 2022-03-13T13:54:36Z The high nutrient low chlorophyll (HNLC) surface waters of the Southern Ocean are characterised by high concentrations of nitrate and phosphate, low concentrations of dissolved iron and deep vertical mixing. Future climate scenarios predict increased surface temperatures and ocean stratification in the region. These changes to vertical mixing will result in a slowdown of nutrient supply to surface waters and an increase in the integrated irradiance in the upper mixed layer. To investigate the influence of iron-limitation and high irradiance on phytoplankton growth and physiology, a 6-day shipboard incubation experiment was conducted during the Sub-Antarctic Zone Sensitivity to Environmental Change (SAZ Sense) voyage using phytoplankton populations from the upper mixed layer in the north-eastern SAZ region. Iron-limitation was induced with an organic siderophore and was compared with a 1nM iron-enriched incubation and an unamended treatment (under silicate replete conditions). As expected, iron enrichment led to dominance by large diatoms and enhanced photosynthetic performance, while the iron-limited community showed a decline in total chl a and photochemical efficiency. Under the added stress of high light, the iron-limited community was able to cope with the shift from in situ (<150μmolphotonsm-2s-1) to incubation (mean=765μmolphotonsm-2s-1) irradiance by increasing the proportion of photoprotective pigments and diverting excess light energy via energy-dependent quenching (qE). The responses to iron-limitation under high light showed that the phytoplankton community was able to acclimate to these conditions, but exhibited an overall decline in photosynthetic activity. Data presented here suggest the community shifts, in particular the decrease in diatoms, and the decline in photosynthetic performance of phytoplankton under low iron-high irradiance conditions has the potential to impact future ocean productivity and biogeochemical cycling. © 2011 Elsevier Ltd. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean University of Technology Sydney: OPUS - Open Publications of UTS Scholars Antarctic Southern Ocean |
institution |
Open Polar |
collection |
University of Technology Sydney: OPUS - Open Publications of UTS Scholars |
op_collection_id |
ftunivtsydney |
language |
unknown |
topic |
Oceanography |
spellingShingle |
Oceanography Petrou, K Hassler, CS Doblin, MA Shelly, K Schoemann, V van den Enden, R Wright, S Ralph, PJ Iron-limitation and high light stress on phytoplankton populations from the Australian Sub-Antarctic Zone (SAZ) |
topic_facet |
Oceanography |
description |
The high nutrient low chlorophyll (HNLC) surface waters of the Southern Ocean are characterised by high concentrations of nitrate and phosphate, low concentrations of dissolved iron and deep vertical mixing. Future climate scenarios predict increased surface temperatures and ocean stratification in the region. These changes to vertical mixing will result in a slowdown of nutrient supply to surface waters and an increase in the integrated irradiance in the upper mixed layer. To investigate the influence of iron-limitation and high irradiance on phytoplankton growth and physiology, a 6-day shipboard incubation experiment was conducted during the Sub-Antarctic Zone Sensitivity to Environmental Change (SAZ Sense) voyage using phytoplankton populations from the upper mixed layer in the north-eastern SAZ region. Iron-limitation was induced with an organic siderophore and was compared with a 1nM iron-enriched incubation and an unamended treatment (under silicate replete conditions). As expected, iron enrichment led to dominance by large diatoms and enhanced photosynthetic performance, while the iron-limited community showed a decline in total chl a and photochemical efficiency. Under the added stress of high light, the iron-limited community was able to cope with the shift from in situ (<150μmolphotonsm-2s-1) to incubation (mean=765μmolphotonsm-2s-1) irradiance by increasing the proportion of photoprotective pigments and diverting excess light energy via energy-dependent quenching (qE). The responses to iron-limitation under high light showed that the phytoplankton community was able to acclimate to these conditions, but exhibited an overall decline in photosynthetic activity. Data presented here suggest the community shifts, in particular the decrease in diatoms, and the decline in photosynthetic performance of phytoplankton under low iron-high irradiance conditions has the potential to impact future ocean productivity and biogeochemical cycling. © 2011 Elsevier Ltd. |
format |
Article in Journal/Newspaper |
author |
Petrou, K Hassler, CS Doblin, MA Shelly, K Schoemann, V van den Enden, R Wright, S Ralph, PJ |
author_facet |
Petrou, K Hassler, CS Doblin, MA Shelly, K Schoemann, V van den Enden, R Wright, S Ralph, PJ |
author_sort |
Petrou, K |
title |
Iron-limitation and high light stress on phytoplankton populations from the Australian Sub-Antarctic Zone (SAZ) |
title_short |
Iron-limitation and high light stress on phytoplankton populations from the Australian Sub-Antarctic Zone (SAZ) |
title_full |
Iron-limitation and high light stress on phytoplankton populations from the Australian Sub-Antarctic Zone (SAZ) |
title_fullStr |
Iron-limitation and high light stress on phytoplankton populations from the Australian Sub-Antarctic Zone (SAZ) |
title_full_unstemmed |
Iron-limitation and high light stress on phytoplankton populations from the Australian Sub-Antarctic Zone (SAZ) |
title_sort |
iron-limitation and high light stress on phytoplankton populations from the australian sub-antarctic zone (saz) |
publishDate |
2011 |
url |
http://hdl.handle.net/10453/18065 |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
Deep-Sea Research Part II: Topical Studies in Oceanography 10.1016/j.dsr2.2011.05.020 Deep-Sea Research Part II: Topical Studies in Oceanography, 2011, 58 (21-22), pp. 2200 - 2211 0967-0645 http://hdl.handle.net/10453/18065 |
_version_ |
1766248811906203648 |