Increasing Toxicity of Algal Blooms Tied to Nutrient Enrichment and Climate Change
As nutrient enrichment, or "eutrophication" increases, so will the proportion of toxin-producing strains of cyanobacteria in harmful algal blooms, scientists said.
Researchers from Oregon State University and the University of North Carolina at Chapel Hill outlined recent findings in an analysis in the journal Science.
A particular concern is Microcystis sp., a cyanobacterium that thrives in warm, nutrient-rich and stagnant waters around the world. Like many cyanobacteria, it can regulate its position in the water column, and often forms green, paint-like scums near the surface.
In a high-light, oxidizing environment, microcystin-producing cyanobacteria have a survival advantage over other forms of cyanobacteria that are not toxic. Over time, they can displace the nontoxic strains, resulting in blooms that are increasingly toxic.
Hans W. Paerl, Timothy G. Otten. Blooms Bite the Hand That Feeds Them. Science, 25 October 2013: Vol. 342 no. 6157 pp. 433-434 DOI: 10.1126/science.1245276
Image: Lake Erie algal bloom. NASA.