Recent rapid salinity rise in three East Antarctic lakes
Research in East Antarctica has shown several recent environmental changes that may be linked to human impacts on climate. In order to detect the influence and context of these changes on coastal aquatic ecosystems we examined lake sediment cores from three lakes in the Windmill Islands, East Antarc...
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ftunivtasecite:oai:ecite.utas.edu.au:42008 2023-05-15T13:12:06+02:00 Recent rapid salinity rise in three East Antarctic lakes Hodgson, DA Roberts, D McMinn, A Verleyen, E Terry, B Corbett, C Vyverman, W 2006 https://doi.org/10.1007/s10933-006-9010-0 http://ecite.utas.edu.au/42008 en eng Springer http://dx.doi.org/10.1007/s10933-006-9010-0 Hodgson, DA and Roberts, D and McMinn, A and Verleyen, E and Terry, B and Corbett, C and Vyverman, W, Recent rapid salinity rise in three East Antarctic lakes, Journal of Paleolimnology, 36, (4) pp. 385-406. ISSN 0921-2728 (2006) [Refereed Article] http://ecite.utas.edu.au/42008 Biological Sciences Ecology Palaeoecology Refereed Article PeerReviewed 2006 ftunivtasecite https://doi.org/10.1007/s10933-006-9010-0 2019-12-13T21:18:40Z Research in East Antarctica has shown several recent environmental changes that may be linked to human impacts on climate. In order to detect the influence and context of these changes on coastal aquatic ecosystems we examined lake sediment cores from three lakes in the Windmill Islands, East Antarctica; Beall Lake, Holl Lake and 'Lake M'. Cores were sectioned at 2.5 mm intervals. Their diatom species composition was examined to detect changes in lake salinity using a diatom-salinity transfer function, and their algal pigment content was examined to detect photoautotrophic community responses to environmental change. Results showed that Holl Lake originated in a depression exposed by Holocene recession of the continental ice sheet and that Beall Lake and Lake M originated as isolated marine basins formed by changes in relative sea level. A general late Holocene trend of declining lake salinity was evident in all three lakes, interrupted by one short-term high salinity event in Beall Lake. This is consistent with a long-term positive moisture balance. This general decline in salinity has been followed by a remarkable recent rapid increase in salinity in all three lakes in the last few decades. We speculate that this rapid increase in salinity might be linked to changes taking place in the region including feedbacks resulting from decreasing sea ice extent as recorded in the nearby Law Dome ice core, and positive feedbacks in the catchments whereby reduced snow cover has led to decreased albedo, which in turn has caused increased evaporation and sublimation. Collectively these changes have shifted the lakes across a threshold from positive to negative moisture balance. A minor, but not rapid shift in the abundance of diatom pigments relative to pigments from green algae and cyanobacteria was also detected suggesting that some changes in photoautotrophic community composition have occurred. Measurements of modern nutrient levels are also higher than would be expected in Beall Lake and Holl Lake, given the extremely low sediment accumulation rates. This may be associated with a c. 300% increase in the population of Adlie penguins in the Windmill Islands recorded since the 1950s, or may a first signs of a rapid increase in catchment development and associated lake productivity as experienced in Antarctic and Arctic lakes subject to recent rapid regional warming. The most marked feature of the records is the rapid increase in salinity in all three lakes in the last few decades, which has occurred in lakes both with and without resident penguin populations. 2006 Springer Science+Business Media, Inc. Article in Journal/Newspaper albedo Antarc* Antarctic Antarctica Arctic East Antarctica ice core Ice Sheet Sea ice Windmill Islands eCite UTAS (University of Tasmania) Antarctic Arctic East Antarctica Law Dome ENVELOPE(112.833,112.833,-66.733,-66.733) Windmill Islands ENVELOPE(110.417,110.417,-66.350,-66.350) Journal of Paleolimnology 36 4 385 406 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Biological Sciences Ecology Palaeoecology |
spellingShingle |
Biological Sciences Ecology Palaeoecology Hodgson, DA Roberts, D McMinn, A Verleyen, E Terry, B Corbett, C Vyverman, W Recent rapid salinity rise in three East Antarctic lakes |
topic_facet |
Biological Sciences Ecology Palaeoecology |
description |
Research in East Antarctica has shown several recent environmental changes that may be linked to human impacts on climate. In order to detect the influence and context of these changes on coastal aquatic ecosystems we examined lake sediment cores from three lakes in the Windmill Islands, East Antarctica; Beall Lake, Holl Lake and 'Lake M'. Cores were sectioned at 2.5 mm intervals. Their diatom species composition was examined to detect changes in lake salinity using a diatom-salinity transfer function, and their algal pigment content was examined to detect photoautotrophic community responses to environmental change. Results showed that Holl Lake originated in a depression exposed by Holocene recession of the continental ice sheet and that Beall Lake and Lake M originated as isolated marine basins formed by changes in relative sea level. A general late Holocene trend of declining lake salinity was evident in all three lakes, interrupted by one short-term high salinity event in Beall Lake. This is consistent with a long-term positive moisture balance. This general decline in salinity has been followed by a remarkable recent rapid increase in salinity in all three lakes in the last few decades. We speculate that this rapid increase in salinity might be linked to changes taking place in the region including feedbacks resulting from decreasing sea ice extent as recorded in the nearby Law Dome ice core, and positive feedbacks in the catchments whereby reduced snow cover has led to decreased albedo, which in turn has caused increased evaporation and sublimation. Collectively these changes have shifted the lakes across a threshold from positive to negative moisture balance. A minor, but not rapid shift in the abundance of diatom pigments relative to pigments from green algae and cyanobacteria was also detected suggesting that some changes in photoautotrophic community composition have occurred. Measurements of modern nutrient levels are also higher than would be expected in Beall Lake and Holl Lake, given the extremely low sediment accumulation rates. This may be associated with a c. 300% increase in the population of Adlie penguins in the Windmill Islands recorded since the 1950s, or may a first signs of a rapid increase in catchment development and associated lake productivity as experienced in Antarctic and Arctic lakes subject to recent rapid regional warming. The most marked feature of the records is the rapid increase in salinity in all three lakes in the last few decades, which has occurred in lakes both with and without resident penguin populations. 2006 Springer Science+Business Media, Inc. |
format |
Article in Journal/Newspaper |
author |
Hodgson, DA Roberts, D McMinn, A Verleyen, E Terry, B Corbett, C Vyverman, W |
author_facet |
Hodgson, DA Roberts, D McMinn, A Verleyen, E Terry, B Corbett, C Vyverman, W |
author_sort |
Hodgson, DA |
title |
Recent rapid salinity rise in three East Antarctic lakes |
title_short |
Recent rapid salinity rise in three East Antarctic lakes |
title_full |
Recent rapid salinity rise in three East Antarctic lakes |
title_fullStr |
Recent rapid salinity rise in three East Antarctic lakes |
title_full_unstemmed |
Recent rapid salinity rise in three East Antarctic lakes |
title_sort |
recent rapid salinity rise in three east antarctic lakes |
publisher |
Springer |
publishDate |
2006 |
url |
https://doi.org/10.1007/s10933-006-9010-0 http://ecite.utas.edu.au/42008 |
long_lat |
ENVELOPE(112.833,112.833,-66.733,-66.733) ENVELOPE(110.417,110.417,-66.350,-66.350) |
geographic |
Antarctic Arctic East Antarctica Law Dome Windmill Islands |
geographic_facet |
Antarctic Arctic East Antarctica Law Dome Windmill Islands |
genre |
albedo Antarc* Antarctic Antarctica Arctic East Antarctica ice core Ice Sheet Sea ice Windmill Islands |
genre_facet |
albedo Antarc* Antarctic Antarctica Arctic East Antarctica ice core Ice Sheet Sea ice Windmill Islands |
op_relation |
http://dx.doi.org/10.1007/s10933-006-9010-0 Hodgson, DA and Roberts, D and McMinn, A and Verleyen, E and Terry, B and Corbett, C and Vyverman, W, Recent rapid salinity rise in three East Antarctic lakes, Journal of Paleolimnology, 36, (4) pp. 385-406. ISSN 0921-2728 (2006) [Refereed Article] http://ecite.utas.edu.au/42008 |
op_doi |
https://doi.org/10.1007/s10933-006-9010-0 |
container_title |
Journal of Paleolimnology |
container_volume |
36 |
container_issue |
4 |
container_start_page |
385 |
op_container_end_page |
406 |
_version_ |
1766250363099283456 |