Dyble, J. ., NOAA Great Lakes Environmental, Ann Arbor, USA, juli.dyble@noaa.gov
Fahnenstiel, G. L., NOAA Great Lakes Environmental Research Laboratory, Muskegon, USA, gary.fahnenstiel@noaa.gov
Vanderploeg, H. A., NOAA Great Lakes Environmental Research Laboratory, Ann Arbor, USA, henry.vanderploeg@noaa.gov
Litaker, R. W., NOAA Center for Coastal Fisheries and Habitat Research, Beaufort, USA, wayne.litaker@noaa.gov

ASSESSING THE ROLE OF ENVIRONMENTAL STRESSORS AND GENETIC COMPOSITION ON TOXIN PRODUCTION IN LAKE ERIE CYANOBACTERIAL HAB POPULATIONS

Blooms of the cyanobacterial HAB Microcystis have recently resurged in some regions of the Great Lakes and, due to the use of these waters for drinking water and recreation, there is a significant need to understand the factors contributing to bloom toxicity. Microcystis bloom toxicity is regulated both by environmental factors and genetic composition. The response of the natural Microcystis community to some key environmental stressors (nutrients, light, grazers) was assessed by measuring changes in growth rates and concentration of the toxin microcystin in laboratory experiments. Additionally, a quantitative PCR assay was used to quantify changes in the number of toxic colonies using the mcyB gene, which is involved in the synthesis of the toxin microcystin. The genetic composition of the Microcystis community in western Lake Erie was also assessed over the course of a bloom season using both the highly variable phycocyanin intergenic spacer region (PC-IGS) and mcyB. Sequence analysis showed that there is shift in community composition over time and that strain composition plays a role in Microcystis bloom toxicity in this region.

Oral presentation

Presentation is given by student: No
Session #:120
Date: 03-03-2008
Time: 15:00