Title Inhibition of phytoplankton and bacterial productivity by solar radiation in the Ross Sea polynya
Author Neale, P.J.; Jeffrey, W.H.; Sobrino, C.; Pakulski, J.D.; Phillips-Kress, J.; Baldwin, A.J.; Franklin, L.A.; Kim, H.
Author Affil Neale, P.J., Smithsonian Environmental Research Center, Edgewater, MD. Other: University of West Florida; Center for Environmental Diagnostics and Bioremediation
Source p.299-308, ; Smithsonian at the poles, Washington, DC, May 3-4, 2007, edited by I. Krupnik, M.A. Lang and S.E. Miller. Publisher: Smithsonian Institution Scholarly Press, Washington, DC, United States. ISBN: 978-0-9788460-1-50-9788460-1- X
Publication Date 2009
Notes In English. NSF grants OPP-0127022 and OPP-0127037. 39 refs. Ant. Acc. No: 86095. CRREL Acc. No: 63004408
Index Terms bacteria; ecology; ice; plankton; solar radiation; Southern Ocean--Ross Sea; habitat; International Polar Year 2007-08; IPY 2007-08 Research Publications; phytoplankton; productivity; Ross Sea; sea ice; Southern Ocean
Abstract The Ross Sea polynya is one of the most productive areas of the Southern Ocean; however, little is known about how plankton there respond to inhibitory solar exposure, particularly during the early-spring period of enhanced UVB (290-320 nm) due to ozone depletion. Responses to solar exposure of the phytoplankton and bacterial assemblages were studied aboard the research ice breaker Nathaniel B. Palmer during cruises NBP0409 and NBP0508. Photosynthesis and bacterial production (thymidine and leucine incorporation) were measured during in situ incubations in the upper 10 m at three stations, which were occupied before, during, and after the annual peak of a phytoplankton bloom dominated by Phaeocystis antarctica. Near-surface production was consistently inhibited down to 5-7 m, even when some surface ice was present. Relative inhibition of phytoplankton increased and productivity decreased with increasing severity of nutrient limitation as diagnosed using Fv/Fm, a measure of the maximum photosynthetic quantum yield. Relative inhibition of bacterial production was high for both the high-biomass and postbloom stations, but sensitivity of thymidine and leucine uptake differed between stations. These results provide the first direct evidence that solar exposure, in particular solar ultraviolet radiation, causes significant inhibition of Ross Sea productivity.
URL http://hdl.handle.net/10088/6818
Publication Type monograph
Record ID 292161