A blooming science

Tony Lange

Experts pilot blue-green algae combatants, prevention

Experts don’t know exactly what causes water plants to become toxic, but they know what it feeds on. Starving it of nutrients, however, isn’t as easy as it used to be.

Cyanobacteria, more commonly known as blue-green algae, has become more well-known among inland lakes across Ohio in recent years. As of Wednesday, Wingfoot Lake State Park in Portage County contained toxic levels of the bacteria.

Algal bloom flourishes off phosphorus nutrients, which would reach Ohio’s watersheds from wastewater plants and laundry detergents containing phosphorus until the 1970s, said Dina Pierce, an Ohio Environmental Protection Agency spokeswoman.

“Regulations were tightened down, limiting how much phosphorus could be present in their discharges,” she said about plants. “So that problem marginally went away.”

Although it was not related to cyanobacteria, the 1969 Cuyahoga River fire sparked national attention to plant regulations, and spurred the creation of the U.S. EPA.

Darren Bade, a Kent State biological sciences professor, said the burning river is infamous for the passage of the Clean Water Act in the 1970s, which helped prevent phosphorus discharges from flowing into lakes and rivers. As a result, algal bloom decreased.

Phosphorus Runoffs

During the past decade, however, phosphorus has found new paths into waterways from “non-point” sources, which are sources with multiple points of access rather than one, such as a pipe. Bade said agricultural fertilizers and defective septic systems are examples of this.

“These runoff nutrients, from a variety of sources, are getting into the lakes and essentially making the algae grow better,” Bade said.

The main concern focuses on agriculture, Bade said. For industrial farms, dealing with phosphorus waste from a large concentration of animals can be a problem because the waste is used as manure, as is happens in Ohio and other states that are part of the Corn Belt, Bade said.

“There’s a big push for corn ethanol. Fertilizers need to be placed on corn for it to grow,” Bade said. “So, yes, it might produce green fuel, but there is a lot of chance for pollution to happen within the growth of that corn.”

With a combination of more impervious surfaces, like asphalt, and more land fertilizers, a lot of rain at just the right time can flood extra nutrients to watersheds, he said. With a summer that has been fairly hot and calm, it adds beneficial growing conditions for algae, Bade said.

Natural Combatants

With shallow water and high temperatures, the cyanobacteria can bloom at faster rates, said Heidi Hetzel-Evans, an Ohio Department of Natural Resources spokeswoman.

“With the cooler nights, the water temperature is not staying warm enough for the blue-green algae,” she said. “It is an issue that will naturally subside in the coming weeks.”

That may be the case for the winter months, but in some lakes, the cyanobacteria returns the following spring.

In Grand Lake St. Marys, the largest inland lake in Ohio, algal bloom became toxic late in the summer of 2009.

In 2010, the algae reappeared in May, and microcystin toxin levels reached as high at 2,000 parts per billion, which was well into the top advisory level, Ohio EPA spokeswoman Erin Strouse said. There were still traces of toxins as of September.

Microcystin is the most common of four toxins tested in algal blooms because the World Health Organization has set guidelines for that specific one, Strouse said. A no-swim advisory occurs at 20 ppb.

Short-term Pilot Projects

Last Tuesday night, representatives from the Ohio EPA, ODNR, Ohio Department of Health and Ohio Department of Agriculture met in Celina, near Grand Lake St. Mary’s, to discuss the use of aluminum sulfate, more commonly referred to as alum, to combat the cyanobacteria.

Alum is most commonly used in drinking water, Pierce said. It binds particles and pulls them out of the drinking water. If applied to the lake, it is expected to bind the phosphorus.

“It would carry that to the bottom of the lake so it’s no longer available to the algae,” Pierce said. “It would buy time to implement more permanent practices.”

This is a fairly expensive practice and was experimented with at Twin Lakes in Portage County during the 1970s, Bade said. There have also been experiments with algaecide, which kills the algae.

“There is some concern that killing the algae might actually release some of the toxins, making them worse,” Bade said.

Another pilot project being researched is silica treatment. The process would attempt to flip the conditions so that the green non-toxic algae would become dominant and the cyanobacteria wouldn’t grow, Pierce said.

Long Term Prevention

Treatment trains, a system of treating runoff water in which there are a separator and a filter for clean the water, and sediment traps, which would limit the sources of nutrients flowing down streams are also in the talks to help prevent phosphorus from reaching watersheds, Pierce said.

“The plan is to educate people about what we’re trying to do,” she said. “Educate people on reducing fertilizer use to low or no phosphorus. Not applying manure during the seasons when it doesn’t have a chance to soak in and bettering management practices.”

Pierce compared the algal bloom to a heart attack.

She said the lakes need to be shocked with alum to give them a pulse now, and then they have to be given the proper diet and exercise to stay healthy.

Contact Tony Lange at [email protected].