The Responses of a Natural Bacterioplankton Community to Different Levels of Ultraviolet-B Radiation: A Food Web Perspective.
With the continuing increase of ultraviolet-B radiation (UVBR: 280-320 nm) fluxes toward the Earth's surface, there is concern regarding a possible negative impact on heterotrophic bacterioplankton. The effects of enhanced UVBR on a natural bacterioplankton community were studied during a 7-day experiment conducted in mesocosms (1500 L). Four light regimes were tested: natural light, 280 to 313 nm excluded UVBR, and two levels of UVBR enhancement. During the first 3 days of the experiment characterized by high inorganic nutrient concentrations (nitrates > 1 µmol L-1 and ammonium > 0.1 µmol L-l), UVBR had no effect on both bacterial abundances and activities. From day 4 to the end of the experiment, nitrate concentrations remained low (
Chatila
K.
K
Groupe de Recherche en Environnement Côtier, Institut des sciences de la mer de Rimouski (ISMER), Université du Québec à Rimouski, 310-Allée des Ursulines, Rimouski (Québec), G5L 3A1, Canada.
Demers
S.
S
Mostajir
B.
B
Gosselin
M.
M
Chanut
J.-P.
JP
Monfort
P.
P
Bird
D.
D