“The problem with geosmin is that it is really expensive to measure,” said Andrew Dzialowski, a research associate at the Kansas Biological Survey. “We need to find some other variable we could measure.”
Researchers at the Kansas Biological Survey have been collecting samples from lakes since May 2006. They will analyze the data from these samples and have results by the end of the summer. The researchers’ goal is to develop simple ways to predict when increases of geosmin levels are likely to happen.
“We are trying to do this to help the water plant managers, so they can be alerted that they are going to have a taste and odor problem,” said Paul Liechti, assistant director of the Kansas Biological Survey. “It is a heads up methodology.”
One major problem researchers have faced is the high amount of variables that influence algal blooms. Because of that, they have had to monitor each lake individually. Lakes sampled so far include Clinton Lake, Big Hill Lake, Gardner City Lake, Cheney Reservoir and Marion Reservoir.
“The lakes are individual themselves, so they have different characteristics that accentuate the problems,” Liechti said.
Jason Beury, a chemistry lab assistant at the Kansas Biological Survey, goes to Clinton Lake at least once every two weeks to gather data samples. Temperature, acidity level and oxygen dissolution in the water are some of the measurements gathered.
“You can tell if there is an algal bloom in the lake from a green or blue-green water color, but you can still have algal blooms that are not visually noticeable,” Beury said. “You can also tell from the smell. It’s either a fishy or a musty, earthy smell.”
Source: Kansas Biological SurveyHumans can detect geosmin at levels as low as five parts per trillion, and all five lakes tested have showed samples with higher levels than that.
Making the water taste bad is not the only problem that algal blooms cause; some algae can be hazardous to the environment and human health.
“You can have low oxygen in the water, which results in fish killed, and some species of algae produce algotoxins that can harm humans and animals,” Dzialowski said.
On June 2003, an outbreak of a toxic form of blue-green algae in Marion Reservoir forced Hillsboro, Kan., to suspend water pumping from the reservoir.
“Ultimately we would like to prevent the algal blooms, but that is a really hard task because you would have to change a lot of best management practices,” Dzialowski said.
Best management practices are ways to decrease the impact that storm water runoff have on the environment. When it rains, the nutrients from fertilizers are washed away and deposited in the lake. The algae feed off these nutrients and grow excessively – a process called eutrophication.
“What bothers me is that we are so entrained in this system of commercialized agriculture that it is hurting our lakes,” Beury said.