The Kansas Department of Health and Environment maintains a list of Harmful Algal Blooms throughout the state. So far this summer, ten lakes have been affected by blue-green algae. The organism can be found in most bodies of water, but in large quantities they can pose a health risk to humans and animals.
The setting is a pristine prairie oasis, with birds and insects performing their daily concert. The Great Plains Nature Center is a protected piece of land tucked away in northeast Wichita; nearby you’ll find a small municipal lake at Chisholm Creek Park North.
“I don't know if we're going to see any of the algae, it kind of depends on the way the wind is blowing and what the concentration is,” Jessica Mounts says, a district fisheries biologist for the state of Kansas.
She stands at the banks of the small lake, which features a nice view of Highway 96.
Her job is to maintain fish populations in many Sedgwick, Harvey and Marion county lakes—some of which currently contain cyanobacteria.
“There's a warning for Chisholm Creek Park North Lake and there’s signs posted at the entrance with that warning. Basically, we just ask people to use extra caution when they're fishing."
These signs are necessary because cyanobacteria, often called blue-green algae, is harmful. A toxin within the bacteria, called microcystin, can cause flu like symptoms and even liver damage in humans and pets. As for fish, Jessica Mounts says it can eventually suffocate them.
“The algae itself doesn't cause problems for fish until you have a really bad bloom that starts to die,” Mounts says.
She adds that all organic compounds consume oxygen as they decompose, and because fish depend on dissolved oxygen in water to breath—just like we depend on oxygen from the air—the dead algae causes the fish to run out of oxygen and die.
None of the lakes Mounts looks after have gotten to that point, but a fish kill near Great Bend earlier this month wiped out the entire fish population. When this happens, the lake will eventually regenerate itself; the algae bloom will clear away and oxygen levels will return to normal. She says that can take 24 hours, or it could take weeks.
“We would try and restock the lake, but we'd also look at solutions for reducing the amount of nutrients going into the lake, which is the ultimate cause of excessive algae blooms,” Mounts says. “Things that are in your fertilizer: nitrogen, but especially phosphorous.”
Blue-green algae relies on photosynthesis, it gets its energy from the sun. According to Mounts, clear summer days and calm waters can cause algal blooms, but foreign chemicals are what makes them a common problem.
This idea is shared by Kansas health officials.
Tom Langer is Director of Environmental Health for the Kansas Department of Health and Environment.
“Every one of us lives in a watershed, we all contribute to this, whether we live in a city or farm, our activities on the surface contribute to what goes into the water,” Langer says.
In 2010, KDHE created the blue-green algae program after a number of people complained of a rash, headaches and fever. They could all be linked back to lakes containing a harmful algal bloom.
This led the organization to monitor lakes throughout Kansas, ranging from small fishing ponds, to reservoirs like Marion and Milford Lake in north central Kansas--both of which have been affected by blue-green algae this summer. Langer says every year is different.
“In 2011, we had an unusual year. We had a lot of early spring rain, the reservoir had to retain water because of flooding in the Missouri and Mississippi Rivers and we had exceptionally warm temperatures and exceptionally calm days. And we saw algal blooms that just skyrocketed.”
Langer says the flooding brought fertilizers from crop fields back into lakes. After droughts in 2012 and 2013, this year is the first they’ve been able to monitor what a moderate spring and summer looks like. So far, harmful algal blooms are way down from 2011, but still high. The ugliest case is Veteran’s Memorial Lake, near Great Bend, where blue-green algae has killed every last fish.
“Veterans Lake has been, what we consider to be, extremely chronic,” Langer explains. “That lake has not been off an advisory or warning status for the entire time we've had a program that’s monitored the lake.”
The problems created by these algal blooms go further than a rash or fever. Dogs, as well as livestock, have died from ingesting toxins from blue-green algae. It can hurt tourism and local economies when advisories and warnings keep people from using lakes. And in really bad cases, like Toledo, Ohio earlier this month, it can invade water supplies and cause a drinking water crisis. Langer says the answer is to limit the use of chemical fertilizers, especially when you’re near bodies of water.
“I might have a lawn, I want it to be nice and green in my town and I fertilize that thing 2-3 times in the spring and again in the fall and I'm putting all kinds of chemicals on there and when it rains, my grass turns a beautiful shade of green. But, a lot of that is just washing down stream, and if I do that and a thousands neighbors are doing that in my community, then what are we doing?” Langer says.
Once these algal blooms have started, there’s not much wildlife agencies can do. They have to wait it out. That’s why, according to Langer, prevention is the key. That means using fewer fertilizers that contain nitrogen and phosphorous, and farmers controlling the water that runs off of their crops.
“The plan has to be local, it has to come from the locals. All we can do is hope the message gets to the right people,” Langer says. “When you can't use a lake anymore, or it gets so bad its utility as a recreational outlet or income driver for local economies is gone, maybe at that point and time they’ll say, ‘Hey, we’ve had enough of this.’”
In Ohio and Michigan, an estimated 400,000 people were forced to drink bottled water after blue-green algae invaded Lake Erie in early August. Health officials there also blame nutrients from fertilizers for these algal blooms.
According to KDHE, Kansas is at low risk of blue-green algae invading drinking supplies.
When an Advisory is issued, KDHE recommends the following precautions be taken:
- Humans, pets, and livestock do not drink untreated lake water
- Clean fish and rinse with clean water, consume only the fillet portion, discarding other parts
- Do not eat or allow pets to eat dried algae
- If lake water comes in contact with skin or pet fur, wash with clean potable water as soon as possible
- Avoid areas of visible algae accumulation
Follow Sean Sandefur on Twitter, @SeanSandefur
Originally Aired on Morning Edition on 08/22/2014