Ecosystem Research and Harmful Algal Blooms
The recent increases in cyanobacterial Harmful Algal Blooms in the Great Lakes has caused significant concern for human and ecosystem health due to the production of toxins by bloom species. In the Great Lakes, Microcystis dominates the cyanobacterial bloom community and produces the hepatotoxin microcystin (Brittain et al. 2000, Carmichael 1994, 1997, Vanderploeg et al. 2001). Preliminary studies have documented the presence of microcystins in the Great Lakes, at times exceeding the recommended limit of 1 µg L-1 of microcystin established by the World Health Organization for drinking water supplies (Brittain et al. 2000, Vanderploeg et al. 2001). The increase in large Microcystis blooms in recent years has caused considerable concern due to the dependence on these waters as a resource and the health risks attributable to microcystins. The ability to accurately measure the distribution and concentration of microcystin in the Great Lakes, including the various microcystin congeners, is therefore essential to protecting human and ecosystem health in this region. In 2003, microcystin concentrations throughout Saginaw Bay and western Lake Erie were commonly above 1 µg L-1 and as high as 58 µg L-1 in wind-accumulated scums (Dyble et al. submitted). Thus, concentrations of microcystin in the Great Lakes may pose a threat to human and ecosystem health.
2006 Milestones and Progress:
Monitoring and mapping of
toxin producing strains of Microcystis in western Lake Erie and Saginaw Bay took
place during summer of 2006. The proportion of toxic genotypes in environmental
samples was identified. Experimentation to determine the influence of light and
phosphorus on microcystin concentrations in environmental samples as well as distinguishing
which environmental variable has more control over microcystin cells. Determination
of the temporal distribution of toxic Microcystis strains in western Lake Erie and
Saginaw Bay.
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Projects
| Project Title | Researcher(s)/Affiliation |
| Genetic and environmental factors influencing Microcystis bloom toxicity | Juli Dyble (NOAA/GLERL), Dr. Gary Fahnenstiel (NOAA/GLERL), Dr Wayne Litaker (NOAA, Beaufort NC) |
| Evaluation of the Hazard of Microcystis Blooms for Human Health through Fish Consumption | Peter Landrum, (NOAA/GLERL), Juli Dyble, (NOAA/GLERL), Duane Gossiaux (NOAA/GLERL), Steve Pothoven (NOAA/GLERL) |
