Hitchcock, G. L., University of Miami/RSMAS, Miami, USA, g.hitchcock@miami.edu
Crawford, D. ., University of Miami/RSMAS, Miami, USA, dcrawford@rsmas.miami.edu

PRODUCTION AND RESPIRATION RATES IN KARENIA BREVIS

Karenia brevis is the dinoflagellate responsible for harmful algal blooms in Florida coastal waters. Field and laboratory rates of photoautotrophic carbon uptake have been measured in this species, but few reports exist of its respiration or net production rates; these are essential to refine models to predict development and maintenance of coastal blooms. We are conducting a study of the carbon physiology and genomic signatures of K. brevis in cultures and natural populations. Net community production and respiration rates from ‘light-dark’ bottle incubations of K. brevis populations during summer 2006 revealed ‘red tides’ along Florida’s west coast are predominantly autotrophic (P > R). An automated productivity incubator deployed in a dense (500,000 - 2,000,00 cells/L) population in Sarasota Bay reinforced this conclusion. Enhanced respiration rates at dusk were attributed to a close coupling between Karenia and the microbial loop, and the potential for light-enhanced dark respiration. Culture studies are underway to verify production and respiration rates, and the genomic signatures, of a Sarasota Bay clone where growth is regulated by light.

Poster presentation

Presentation is given by student: No
Session #:120
Date: 03-03-2008
Time: 17:30 - 19:30