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Late Pleistocene record of elevated UV radiation in an Antarctic lake

Hodgson, Dominic A.; Vyverman, Wim; Verleyen, Elie; Leavitt, Peter R.; Sabbe, Koen; Squier, Angela H.; Keely, Brendan J.. 2005 Late Pleistocene record of elevated UV radiation in an Antarctic lake. Earth and Planetary Science Letters, 236 (3-4). 765-772. 10.1016/j.epsl.2005.05.023

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Abstract/Summary

Elevated ultraviolet irradiance (UVR, 280–400 nm) damages DNA and induces reorganisation within biological communities at the Earth's surface. Southern high latitude aquatic ecosystems may be particularly susceptible because of low stratospheric ozone levels and extremely low contents of photoprotective dissolved organic matter (DOM). Surveys of shallow lakes and ponds in eastern Antarctica show that cyanobacteria survive elevated UVR exposure by increasing extra-cellular concentrations of photoprotective compounds, which are preserved in sediments together with photosynthetic pigments. Thus, reconstruction of long-term changes in biological UVR receipt, to provide a context for evaluating the long-term significance of recent changes in ozone column depth, is feasible in Antarctic settings. The sediment in Lake Reid (69° 23′ S, 76° 53′ E), Antarctica, spans the late-Pleistocene and contains UVR-absorbing pigments from benthic cyanobacteria. Here we show that mean exposure of these benthic cyanobacteria to UVR during the last glacial was more than three times higher than during the Holocene, likely due to short periods of photosynthetic activity coinciding with relatively high UVR fluxes, or due to increased UVR transmission to the Earth's surface resulting from changes in external factors such as stratospheric ozone levels, cloud cover and surface albedo.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1016/j.epsl.2005.05.023
Programmes: BAS Programmes > Antarctic Science in the Global Context (2000-2005) > Signals in Antarctica of Past Global Changes
ISSN: 0012-821X
Additional Keywords: Ultraviolet radiation, Ozone hole, Lakes, Sediments, Cyanobacteria
NORA Subject Terms: Ecology and Environment
Earth Sciences
Date made live: 21 Dec 2007 14:55
URI: http://nora.nerc.ac.uk/id/eprint/1810

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