Aquatic Sciences Meeting, Albuquerque 2001

CS04 Benthic-Pelagic Coupling: Seasonality, Pulses, and Flux

Date: Thursday, February 15, 2001, Time: 4:45:00 PM

Location: Mesilla

Hersha, D, K, University of Akron, Akron, Ohio, USA, dhersha@neo.rr.com

Kovalcik, P, A, University of Akron, Akron. Ohio, USA, pakoval@uakron.edu

Lavrentyev, P, J, University of Akron, Akron, Ohio, USA, peter1@uakron.edu

THE ENHANCED MICROBIAL FOOD WEB ASSOCIATED WITH A LARGE-SCALE CROSS-MARGIN SEDIMENT TRANSPORT IN LAKE MICHIGAN

The composition, distribution, and grazing rates of pelagic protists were examined along 5 nearshore-offshore transects in southern Lake Michigan from February through April in 1998-2000 as a part of the Episodic Event Great Lakes Experiment (www.glerl.noaa.gov/eegle). The significant spatial and temporal variability of these microbial food web parameters was to a large extent related to a massive storm-induced transport of re-suspended coastal sediments to the offshore waters. Under these conditions, suspension-feeding choreotrich ciliates and heterotrophic and mixotrophic nanoflagellates became predominant. This shift in the microbial community structure corresponded to increased bacterial growth rates (3H-thymidine incorporation, Cotner et al. 2000) and the closely matching bacterivory rates (dilution and fluorescently labeled bacteria). Combined with tight trophic couplings between micro- and mesozooplankton (Kovalcik et al., this meeting), our results indicate that a large proportion of heterotrophic production created during the re-suspension events may become available to the higher trophic levels during the critical winter-spring transition.

This Session Listing

Aquatic Sciences Meeting, Albuquerque 2001

Quicklinks