SS2.01 Effects of Biotic Interactions on the Structure and Function of Microbial Food Webs
Date: Wednesday, June 12, 2002
Location: Poster Session - VCC
 
FirstMR, The University of Akron, Akron, USA, mrf3@uakon.edu
Lavrentyev, P, J, The University of Akron, Akron, USA, mrf3@uakron.edu
 
MICROZOOPLANKTON RESPONSE TO MULTIPLE GRADIENTS IN TEXAS COASTAL WATERS
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Microzooplankton composition, distribution, and grazing were examined in March and June-July 2001 in the northwestern Gulf of Mexico and several coastal bays, estuaries, and lagoons along the Texas coast. The studied locations represented a wide spectrum of trophic conditions and salinity. In the oligotrophic Gulf waters, microzooplankton biomass (5-10 ug C/l) was formed primarily by oligotrichs and gymnodinioids. In coastal waters, microzooplankton (20-70 ugC/l) had an elevated proportion of tintinnids, hypotrichs and armored dinoflagellates. Microzooplankton herbivory rates measured via dilution and size-fractionation varied from 0 to 2.1 d-1, and often exceeded phytoplankton growth rates. In the hypersaline region of Laguna Madre affected by a persistent brown tide due to the pelagophyte Aueroumbra lagunensis, the maximum microzooplankton biomass (86 ugC/l) corresponded to very low herbivory and phytoplankton growth rates, suggesting indirect energy transfer between micrograzers and pelagophytes.