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Effects of artificial ultraviolet-B radiation on experimental aquatic microcosms

De Lange, H.J. and Verschoor, A.M. and Gylstra, R. and Cuppen, J.G.M. and Van Donk, E. (1999) Effects of artificial ultraviolet-B radiation on experimental aquatic microcosms. Freshwater Biology, 42, 545-560. ISSN 0046-5070.

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Official URL: http://dx.doi.org/10.1046/j.1365-2427.1999.00478.x

Abstract

1. The effects of prolonged ultraviolet-B (UVB) radiation on freshwater communities were studied in indoor microcosms (600 L) with artificial light sources, simulating a clear, shallow, mesotrophic aquatic ecosystem. A range of six intensities (in duplicate) of UVB radiation, ranging from 0 (control) to 9.56 kJ m(-2) day(-1) at the water surface, was applied for 8 weeks. The UVB radiation levels, attenuation, shading and scattering were comparable to those in Dutch shallow freshwater systems. Physical, chemical and biological variables were monitored weekly. 2. The WE treatment did not affect the abundance, species composition or biovolume of the phytoplankton or zooplankton communities, nor did it affect the periphyton or the macroinvertebrate community. A few species showed a significant response on some of the sampling dates, but there was no negative UVB effect at the community level. Overall, the ecosystems in the microcosms were not affected by the UVB treatment. 3. In a bio-assay, a laboratory clone of Daphnia pulex, not subjected to UVB radiation, was fed with seston from the microcosms. Daphnia pulex feeding on seston from the control microcosms grew faster, had better survival and better reproduction than D. pulex feeding on seston from the UVB treated microcosms. The phytoplankton-zooplankton interaction may have been influenced by the UVB treatment. 4. The dissolved oxygen content (DOC) concentrations in the microcosms were around 5 mg L-1. The DOC levels in Dutch systems rarely fall below 10 mg L-1. This might provide sufficient protection against the detrimental effects of increased UVB radiation. [KEYWORDS: ecosystem, macroinvertebrates, macrophytes, microcosm, phytoplankton, UVB, zooplankton]

Item Type:Article
Institutes:Nederlands Instituut voor Ecologie (NIOO)
ID Code:10721
Deposited On:25 Nov 2011 01:00
Last Modified:31 Mar 2014 10:51

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