Aquatic Sciences Meeting, Albuquerque 2001

SS44 Auto-Heterotrophic Coupling Across Trophic Gradients In Lakes and Oceans (Spatial and Temporal Connections)

Date: Monday, February 12, 2001, Time: 4:45:00 PM

Location: Sandia/Santa Ana

Biddanda, B, A, University of Minnesota, Saint Paul, USA, bidda001@tc.umn.edu

Cotner, J, B, University of Minnesota, Saint Paul, USA, cotne002@tc.umn.edu

CARBON FLUX THROUGH BACTERIOPLANKTON IN SOUTHERN LAKE MICHIGAN: A LARGE AND SEASONALLY VARIABLE FRACTION OF PRIMARY PRODUCTION

Although respiration is commonly the dominant component of heterotrophic metabolism, very little is known regarding plankton respiration rates in the Great Lakes. And even though bacteria are considered to be responsible for a major share of plankton respiration in natural waters, there are no such estimates for the Great Lakes region. During 1999 winter and summer months, we measured plankton and bacterial respiration, bacterial production in southern Lake Michigan and then compared bacterial carbon demand to primary production. Results suggest that plankton respiration rates were lower in March than in June by an order of magnitude. Contribution of bacteria to planktonic respiration was substantial, and ranged from 23-66% in the winter and from 20-75% in the summer. On the basis of bacterial carbon demand (growth + respiration), we estimate that an average of ~18% of winter-time primary production and ~132% of summer-time primary production was consumed (respired for the most part) by bacteria in southern Lake Michigan. Bacteria consume a large and seasonally variable fraction of primary production in natural waters.

Return to This Session's Schedule · Complete Session Listing ·

Aquatic Sciences Meeting, Albuquerque 2001

Quicklinks