Spatial and Seasonal Variations of the Island Mass Effect at the Sub-Antarctic Prince Edward Islands Archipelago
At the sub-Antarctic Prince Edward Islands (PEIs) in the Southern Ocean, the Island Mass Effect (IME) plays an important role in maintaining an ecosystem able to support diverse biological communities; however, limited in situ sampling has severely constrained our understanding of it. As such, our s...
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ftunivcapetownir:oai:localhost:11427/36649 2023-05-15T13:54:58+02:00 Spatial and Seasonal Variations of the Island Mass Effect at the Sub-Antarctic Prince Edward Islands Archipelago Lamont, Tarron Toolsee, Tesha 2022-04-29 application/pdf http://hdl.handle.net/11427/36649 https://open.uct.ac.za/bitstream/11427/36649/1/remotesensing-14-02140.pdf en eng Faculty of Science Department of Oceanography http://hdl.handle.net/11427/36649 https://open.uct.ac.za/bitstream/11427/36649/1/remotesensing-14-02140.pdf http://creativecommons.org/licenses/by/4.0/ CC-BY Remote Sensing https://www.mdpi.com/journal/remotesensing 14 9 2140 Journal Article 2022 ftunivcapetownir 2022-09-13T05:51:40Z At the sub-Antarctic Prince Edward Islands (PEIs) in the Southern Ocean, the Island Mass Effect (IME) plays an important role in maintaining an ecosystem able to support diverse biological communities; however, limited in situ sampling has severely constrained our understanding of it. As such, our study used satellite chlorophyll a (chla) to provide the first detailed characterisation of the spatial extent and seasonal variability of the IME at the PEIs. Seasonal surface chla variations were remarkable, with localised increases observed from mid-austral spring to the end of autumn (October to May). In contrast, during June to September, there were no distinguishable differences between chla at the PEIs and that further afield. Seasonal chla changes were significantly correlated with higher light levels, warmer waters, and shallow upper mixed layer depths reflecting enhanced water column stability during summer and autumn, with the opposite pattern in winter and spring. The IME extended northeast of the islands and remained spatially distinct from elevated chla around the northern branch of the sub-Antarctic Front and the southern branch of the Antarctic Polar Front. From December to February, the IME was spatially connected to the island shelf. In contrast, during March–May and in October, higher chla was observed only to the northeast, some distance away from the islands, suggesting a delayed IME, which has not previously been observed at the PEIs. The clear association of this higher chla with the weak mean geostrophic circulation northeast of the islands suggested retention and accumulation of nutrients and phytoplankton biomass, which was likely aided by wind-driven northeastward transport of water from the shelf. Climatological mean chla to the northeast was generally higher than that on the PEI shelf, and further research is required to determine the importance of this region to ecosystem functioning at the islands. Article in Journal/Newspaper Antarc* Antarctic Prince Edward Islands Southern Ocean University of Cape Town: OpenUCT Antarctic Austral Southern Ocean The Antarctic |
institution |
Open Polar |
collection |
University of Cape Town: OpenUCT |
op_collection_id |
ftunivcapetownir |
language |
English |
description |
At the sub-Antarctic Prince Edward Islands (PEIs) in the Southern Ocean, the Island Mass Effect (IME) plays an important role in maintaining an ecosystem able to support diverse biological communities; however, limited in situ sampling has severely constrained our understanding of it. As such, our study used satellite chlorophyll a (chla) to provide the first detailed characterisation of the spatial extent and seasonal variability of the IME at the PEIs. Seasonal surface chla variations were remarkable, with localised increases observed from mid-austral spring to the end of autumn (October to May). In contrast, during June to September, there were no distinguishable differences between chla at the PEIs and that further afield. Seasonal chla changes were significantly correlated with higher light levels, warmer waters, and shallow upper mixed layer depths reflecting enhanced water column stability during summer and autumn, with the opposite pattern in winter and spring. The IME extended northeast of the islands and remained spatially distinct from elevated chla around the northern branch of the sub-Antarctic Front and the southern branch of the Antarctic Polar Front. From December to February, the IME was spatially connected to the island shelf. In contrast, during March–May and in October, higher chla was observed only to the northeast, some distance away from the islands, suggesting a delayed IME, which has not previously been observed at the PEIs. The clear association of this higher chla with the weak mean geostrophic circulation northeast of the islands suggested retention and accumulation of nutrients and phytoplankton biomass, which was likely aided by wind-driven northeastward transport of water from the shelf. Climatological mean chla to the northeast was generally higher than that on the PEI shelf, and further research is required to determine the importance of this region to ecosystem functioning at the islands. |
format |
Article in Journal/Newspaper |
author |
Lamont, Tarron Toolsee, Tesha |
spellingShingle |
Lamont, Tarron Toolsee, Tesha Spatial and Seasonal Variations of the Island Mass Effect at the Sub-Antarctic Prince Edward Islands Archipelago |
author_facet |
Lamont, Tarron Toolsee, Tesha |
author_sort |
Lamont, Tarron |
title |
Spatial and Seasonal Variations of the Island Mass Effect at the Sub-Antarctic Prince Edward Islands Archipelago |
title_short |
Spatial and Seasonal Variations of the Island Mass Effect at the Sub-Antarctic Prince Edward Islands Archipelago |
title_full |
Spatial and Seasonal Variations of the Island Mass Effect at the Sub-Antarctic Prince Edward Islands Archipelago |
title_fullStr |
Spatial and Seasonal Variations of the Island Mass Effect at the Sub-Antarctic Prince Edward Islands Archipelago |
title_full_unstemmed |
Spatial and Seasonal Variations of the Island Mass Effect at the Sub-Antarctic Prince Edward Islands Archipelago |
title_sort |
spatial and seasonal variations of the island mass effect at the sub-antarctic prince edward islands archipelago |
publisher |
Faculty of Science |
publishDate |
2022 |
url |
http://hdl.handle.net/11427/36649 https://open.uct.ac.za/bitstream/11427/36649/1/remotesensing-14-02140.pdf |
geographic |
Antarctic Austral Southern Ocean The Antarctic |
geographic_facet |
Antarctic Austral Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Prince Edward Islands Southern Ocean |
genre_facet |
Antarc* Antarctic Prince Edward Islands Southern Ocean |
op_source |
Remote Sensing https://www.mdpi.com/journal/remotesensing 14 9 2140 |
op_relation |
http://hdl.handle.net/11427/36649 https://open.uct.ac.za/bitstream/11427/36649/1/remotesensing-14-02140.pdf |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
_version_ |
1766261176552914944 |