CS06 Benthos
Date: Friday, June 14, 2002
Time: 8:30:00 AM
Location: Colwood
 
CarmanKR, Louisiana State University, Baton Rouge, USA, zocarm@lsu.edu
Pinckney, J, , Texas A&M University, College Station, USA, pinckney@ocean.tamu.edu
 
PLEASE PASS THE DIATOMS: RELATIONSHIPS BETWEEN BENTHIC CONSUMERS AND MICROALGAE IN A SALT MARSH MUDFLAT
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Manipulative field experiments in a Louisiana salt marsh were conducted to determine the influences of nutrient availability and grazing pressure on benthic microalgal (BMA) biomass, production, and community structure, and the relationship between BMA and benthic consumers. Experiments were repeated in winter and summer over a 3-year period. Fertilizer addition to 1 m2 mudflat plots had no influence on BMA. BMA biomass varied seasonally, and was significantly higher in winter. Biomass-specific productivity was, however, highest in summer. 14C measurements of grazing pressure on BMA indicated that grazing was approximately equivalent to BMA production during the summer, but less than BMA production during the winter. Stable-isotope (13C and 15N) analyses suggest that BMA (primarily diatoms) contributes significantly to the diets of benthic consumers in both winter and summer, but detritus from Spartina alterniflora becomes proportionately more important during the winter.