Aquatic Sciences Meeting, Albuquerque 2001

SS08 Processes at the Benthic Interface (Environmental Connections)

Date: Tuesday, February 13, 2001, Time: 2:30:00 PM

Location: Ruidoso/Pecos

Lowe, R, L, Bowling Green State University, Department of Biological Sciences, Bowling Green, OH, USA, lowe@bgnet.bgsu.edu

Gooden, W, S, Bowling Green State University, Department of Biological Sciences , Bowling Green, OH, USA, WBSG@GATEWAY.NET

Greenwood, J, L, University of Georgia, Institute of Ecology, Athens, GA, USA, jgreenw@sparc.ecology.uga.edu

Belanger, S, E, The Procter & Gamble Company, Cincinnati, OH, USA, belanger.se@pg.com

DIEL BEHAVIOR PATTERNS OF DIATOMS IN STREAM SEDIMENTS

Observations made during studies at The Procter & Gamble Company's Experimental Stream Facility (ESF) showed stream sediments shifting in color from a pale beige during the night to a deep golden brown within the first five hours of light. Stream sediments were collected during nighttime and daylight conditions. Sediments were field-fixed with gluteraldehyde, flash-frozen in liquid nitrogen, then freeze-fractured and examined with scanning electron microscopy. The fractured face of stream sediments collected during dark and light conditions was analyzed for vertical algal cell distribution in nighttime vs. daytime periods. The sediments were dominated by motile diatoms, which were seen down to 15 mm below the sediment surface. The dominant large benthic diatom Gyrosigma acuminatum appears to migrate toward the surface of the sediments during the day and is responsible for the browning of the sediments.

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Aquatic Sciences Meeting, Albuquerque 2001

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