Lake Erie and other large recreational bodies of water are no longer the only areas of concern when it comes to harmful algae.
Smaller lakes and ponds, especially in agricultural areas, are being affected by toxins released from harmful algae, causing alarm for not only human and animal health, but biodiversity and the ecosystem, according to a recent study by an Ohio State research team.
The study, led by Jiyoung Lee, an associate professor of environmental health sciences at Ohio State’s College of Public Health, analyzed 24 samples over a three-month period in 2015. Ten of the sites were found to have high levels of toxins.
Contributors to the study included Siobhan Fennessy and Joan Slonczewski of Kenyon College, who collected the water samples, and Igor Mrdjen, one of the authors who graduated from Ohio State this year.
Toxins from algae can affect people through ingestion, inhalation or direct contact, resulting in skin rashes, intestinal problems and damage to the liver, Lee said. However, she said a larger problem exists.
“It’s beyond that sort of toxin issue,” Lee said. “We found that predominance of bacteria affects trophic level, so it really affects biodiversity and ecosystem health. It affects the next level of biological organisms.”
The bacteria to which Lee is referring are the algae, and trophic level refers to the levels in the ecosystem in which organisms reside.
“We can see this cascading effect, so bacterial bloom can affect another group, and it can affect the food chain,” Lee said. “Trophic level balance can be shifted and maybe broken.”
The existence of an algal bloom means there is too much harmful algae present. And in these agricultural areas, the harmful algae reach toxic levels because of tile drainage — a process farmers use in crop production by which plastic piping runs below the surface — carrying excess water and its nutrients to the water.
“Ohio is a water-rich state,” Lee said. “So, sometimes in the soil, [the crops] have a little too much moisture, so it’s not good for your crop production.”
The nutrients, particularly nitrogen and phosphorus, become harmful when they reach the algae.
Lee’s interest in smaller lakes and ponds stemmed from the fact that routine monitoring typically focuses on larger bodies of water, such as Lake Erie. She said more education and communication is needed so lakes and ponds get the necessary attention from academia, researchers and state agencies.
One lake in the study, which is privately owned by a farm, caught attention because it contained bacteria concentrations 800 times above recreational state guidelines, Seungjun Lee, co-author of the study and a post-doctoral researcher in environmental health sciences at the College of Public Health, said in a statement.
Jiyoung Lee said that while the study focused on harmful algae around rural Ohio, this kind of form can be seen all over the world.
Jiyoung Lee said farmers have been managing their runoff by adding buffers to the edge of the farm fields, as well as taking conditions into account while applying fertilizer.
“So they use the right type of nutrient at the right amount at the right location at the right timing. It’s called the ‘Four R’s.’ That’s kind of what the state of Ohio promotes for our farmers,” Jiyoung Lee said. “Obviously, we need fertilizer for our crop production, but we don’t want to use it excessively.”