Effect of solar ultraviolet radiation on bacterio- and phytoplankton activity in a large coral reef lagoon (southwest New Caledonia)
| Type | : | ACL |
|---|---|---|
| Nature | : | Production scientifique |
| Au bénéfice du Laboratoire | : | Non |
| Statut de publication | : | Publié |
| Année de publication | : | 2008 |
| Auteurs (7) | : | CONAN Pascal JOUX Fabien TORRÉTON J-p PUJO-PAY Mireille DOUKI Thierry ROCHELLE-NEWALL Emma,j MARI Xavier |
| Revue scientifique | : | Aquatic Microbial Ecology |
| Volume | : | 52 |
| Fascicule | : | 1 |
| Pages | : | 83-98 |
| DOI | : | 10.3354/ame01204 |
| URL | : | http://www.int-res.com/articles/ame2008/52/a052p083.pdf |
| Abstract | : | Measurements of underwater solar ultraviolet radiation (UV-R, 280 to 400 nm), particulate (PPP) and dissolved (DPP) primary and bacterial (BP) production allowed us to infer the respective contribution of UV-B (280 to 315 nm) and UV-A (315 to 400 nm) in algal-bacterial interactions in the southwest lagoon of New Caledonia. Differences in and between activities were assessed by in situ exposure of plankton to full sun radiation and shielded for UV-B or UV-R. We found a coherent response of phytoplankton and bacteria in total UV-R inhibition. The deepest limit of UV-R influence was 8 m, and inhibition increased with oligotrophy to reach 55 % for phytoplankton and 75 % for bacteria, at 1 m depth. UV-B contributed up to 50 % to the inhibition, especially near the surface and at the oligotrophic station. The UV-A effect on PPP was stronger than that of UV-B; however, bacteria were more sensitive to UV-B than were phytoplankton. When considering UV-A and UV-B separately, the inhibition response was linear without threshold. However, a threshold of 0.002 for PPP and 0.004 for BP was obtained when considering the ratio UV-B:UV-A. The rate of PPP normalized to chlorophyll concentration (PP(chl)) is proposed to reconcile the large range of inhibition encountered in the literature. A significant linear relationship predicted a PPP inhibition of 60 % in surface water with no significant effect on excretion for cells characterized by a low PP(chl), whereas PPP inhibition should be limited for cells characterized by a PP(chl) higher than 18 mg C (mg chl)(-1) h(-1), even if excretion (DPP) could be slightly stimulated. |
| Mots-clés | : | - |
| Commentaire | : | Times Cited: 19 Joux, Fabien/F-8107-2010; Pujo-Pay, Mireille/E-9547-2011; CONAN, Pascal/B-7646-2011 CONAN, Pascal/0000-0002-2879-9411 0 19 |
| Tags | : | - |
| Fichier attaché | : | - |
| Citation | : |
Conan P, Joux F, Torréton J-P, Pujo-Pay M, Douki T, Rochelle-Newall EJ, Mari X (2008) Effect of solar ultraviolet radiation on bacterio- and phytoplankton activity in a large coral reef lagoon (southwest New Caledonia). Aquat Microb Ecol 52: 83-98 | doi: 10.3354/ame01204
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