Algae in bloom
The appearance of toxic algal blooms in Lake Erie near Toledo last week was not a surprise. A forecast for a significant bloom had been announced last month.
“What was a surprise is that it has happened so early,” said Laura Johnson, research scientist with Heidelberg University’s National Center for Water Quality Research, one of the scientists who made the July announcement.
She said the intensity of the early bloom also was a surprise, but weather patterns and wind direction were the reason the bloom remained stationed at the water intakes of Toledo and other municipalities along the lake.
On a scale of 1-10, this year’s overall bloom was expected to be a 5 or 6. However, Johnson said September and October usually are the worst months for blooms. That means drinking water plants might have to deal with the challenges for the rest of the summer and fall.
“Microcystin levels are substantially higher than the drinking water standards,” she said. “Toledo now knows they’re going to have to up the filtratrion, which they have now done.”
She said other water plants that get water from Lake Erie also are aware of potential problems and making sure filtration systems are up to the task.
Microcystin is the toxin produced by microcystis, a type of blue-green algae, or cyanobacteria, that grows in Lake Erie and produces what are known as harmful algal blooms. Only certain species of blue-green algae form toxins, for reasons that aren’t fully understood.
Microcystin is a concern because it can produce hives or blisters from direct contact with the skin. Swallowing it can cause headaches, fever, nausea, vomiting and diarrhea. Large-scale ingestion can damage the liver.
Toxic blooms usually happen first in Maumee Bay, at the mouth of the Maumee River, and in Sandusky Bay.
“Both are very warm and shallow, with very high percentages of agricultural land in their watersheds,” according to a web page titled “Toledo Harmful Algal Bloom Updates” posted by the Ohio Sea Grant College at Stone Lab to answer the many questions asked of Director Jeff Reutter. “The Maumee is the largest tributary to the Great Lakes and drains 4.2 million acres of agricultural land. As a result, both streams contain very high concentrations of phosphorus.”
Johnson said the cause of the blooms is phosphorous-laden water, which runs into the lake from farm fields, lawns, city streets, parking lots and sewage systems.
She said the general public can help the problem by refraining from putting fertilizer on their lawns or by choosing fertilizers that do not contain phosphorous. People who have septic systems can make sure the systems are operating properly and make repairs and updates to meet current standards.
“That’s about it for the average person,” she said.
While Lake Erie frequently has had outbreaks of blue-green algae blooms through the years, scientists believe three factors are making the present situation different.
Some scientists believe climate change may be playing a role by generating more severe rainstorms, which promote farm runoff and sewer overflows.
Another factor may be invasive zebra and quagga mussels that arrived in the lake in 1980s. Since then, the mussels have been eating beneficial types of algae while leaving the harmful blue-green algae.
However, scientists believe the largest reason is an increase in phosphorus washing into the lake, specifically “dissolved reactive phosphorus” – a form that stimulates algae growth the most. That form often is explained by greater use of no-till agriculture, which means farmer apply manure and fertilizers directly onto a field’s surface instead of working them into the soil. Nutrients on the surface reach streams more quickly during rainstorms.
“The majority of phosphorus, or ‘load,’ comes in during storms. We estimate that 80-90 percent enters the lake during heavy rainstorms,” according to Stone Lab web page.
“A lot of people think the farmers are irresponsibly applying fertilizer to their fields,” Johnson said. “That’s not the case. They are not over-applying in most cases. Farmers are actually very efficient with the phosphorous applications.”
The problem is specific soil types and the method of application, she said. Surface application generally is not the best option.
“The easiest and quickest thing is changing how phosphorous is being applied,” she said. “Trying to incorporate fertilizer into the soil a little bit more would help with runoff.”
Farmers try to apply soil nutrients needed by crops when the crops are best able to use them and when the weather forecast shows the least chance for heavy rain. Fertilizer costs money and farmers try to use it wisely.
But when a surprise storms pop up, nutrients are washed into nearby streams, which feed rivers and end of in Maumee and Sandusky bays and Lake Erie.
In addition to different phosphorous application methods, Johnson said farmers use other management practices on farmland. For example, using cover crops helps to reduce the amount of topsoil that washes into streams and become nutrient-laden sediment. Controlled drainage structures help farmers to control water runoff at certain times of the year.
“There is still a lot of research out on exactly how effective these practices are going to be,” Johnson said. “This is still an active area of research. We’ll continue monitoring and interpreting data both in terms of what’s on the ground and what we find in the water.
She said past research has resulted in the understanding scientists have of the HAB problem and further research will help with further understanding.
“It’s an ongoing process of what works and what doesn’t work,” she said.
As research continues, another aspect of reducing the HAB problem is educating landowners, legislators and the general public.
Conservation programs funded by the federal government are helpful in reducing the problem because they assist farmers in implementing best management practices, Johnson said.
She said a new program in this year’s farm bill, called the Resource Conservation Partnership Program through USDA’s Natural Resources Conservation Service, shows promise in helping agencies work together to reduce problem areas. A Western Lake Erie Partnership has been formed.
“I think that should be very promising,” she said.
Another program has been the Conservation Reserve Enhancement Program, which offers financial incentives for using such practices as grass buffer strips along streams in farm fields.
However, CREP may be on the federal chopping block, according to Charlie Payne, regional wildlife biologist for the Pheasants Forever organization.