Researchers from the University of Michigan are working relentlessly to understand toxicity of the algal bloom in Lake Erie.

There have been ongoing efforts for the reduction of phosphorus, along with other nutrients, from being washed off from farm fields and into Lake Erie after there were alarmingly high amounts of bacterial toxin found in the supply of drinking water surrounding the area, leading to a shutdown of the supply to over 400,000 residents in the Toledo area in August.

Levels of nutrients can help researchers find out when and where algal blooms happen, along with their size. However, what determines the toxicity of the Lake Erie algal bloom has so far baffled scientists, as while the Great Lakes host multiple common species of cyanobacteria, there are only few of them that are toxic.

"We know what causes these blooms: It's nutrients from farm runoff. What we don't fully understand is what determines whether these cyanobacterial blooms are highly toxic or not," said Gregory Dick an oceanographer and marine microbiologist from the University of Michigan.

Dick is also the leader of a project for the application of advanced environmental chemistry and genomics procedures to solve the Lake Erie algal bloom issue.

Dick said that he is hoping that the ongoing study will lead to insights which could be used in computer-based ecological models that can predict cyanobacterial blooms. The research heavily relies on environmental genomics, which gives researchers the process for the extraction and sequencing of genetic material found in samples of Lake Erie. The researchers then piece together and analyze the genomes of which organisms are present in the samples.

When the researchers took samples of Lake Erie right before the Toledo drinking water supply was shut down, Rose Cory, an aquatic geochemist from the University of Michigan, and her colleagues looked for substances that could have played a role in increasing the toxic levels of the cyanobacterial blooms, instead of looking for microbes.

Cory found high levels of hydrogen peroxide, a compound that is commonly found in disinfectants. However, while the hydrogen peroxide found was naturally occurring, the substance is known to have detrimental effects on cyanobacteria, which could have possibly led to the increase in toxic cyanobacteria.

However, no conclusion can yet be drawn from the findings; though it provides evidence that hydrogen peroxide could have a role in the phenomenon enveloping Lake Erie.

Photo: Cathy Smith | Flickr