OMAHA, Neb. (WOWT) - Every summer it blooms, just like it has for two billion years.

Blue-green algae is a form of cyanobacteria and is an organism, but not a plant.

And when the conditions are ripe...

“Probably my favorite description is if somebody dumped John Deere green paint on the water,” said Dave Schumacher, the monitoring section supervisor at the Nebraska Department of Environment and Energy. “Wave action will typically push it up on shore, and when it dies it goes from a john deer green color to almost like a turquoise blue.”

Heading into a week of 100-degree temperatures in parts of Nebraska, two lakes are currently under HAB alerts due to harmful algae blooms: Big Indian Lake and Swanson Reservoir.

In the metro and specifically, Omaha, Lake Cunningham executive director Brook Bench said the state and the Corps of Engineers are rigorous with their regular testing of recreational lakes and beaches across Nebraska.

Lake Cunningham and others in the metro show plenty of seasonal algae, but none of them are currently showing any dangerous levels of anything, especially blue-green algae.

Cyanobacteria like blue-green algae produce a range of toxins that pose a danger to humans and animals

“Lakes like this that were built for flood control, you get a heavy rain, you get a nice flush that comes through, things wash through and it kind of starts the process over again,” Bench said. “We have had some timely rains here in the last few weeks, so that’s been very helpful to keep it balanced and just keep getting fresh water coming in so that definitely has helped with the current algae that we have.”

Since Lake Cunningham doesn’t allow swimming, he’s not as worried about anyone getting exposed to any algae, dangerous or not. He says kayaking, stand-up paddling, boating, and fishing are completely safe.

According to the Nebraska Department of Environment and Energy, “HABs can dominate the algal populations of a lake under the right combinations of water temperature, low water depths, and nutrients (such as high nitrogen and phosphorus concentrations from wastewater discharges and runoff from agricultural land and communities).”

The NDEE advises to watch for the following aspects in lake water or at beaches:

  • Water that has a neon green, pea green, blue-green or reddish-brown color.
  • Water that has a bad odor.
  • Foam, scum, or a thick paint-like appearance on the water surface.
  • Green or blue-green streaks on the surface.
  • Areas with algae that look like grass clippings floating in the water.
  • When algal blooms are present at a lake, avoid protected bays and shorelines on the windward side of the lake. These are areas that generally have higher concentrations of algae and potentially toxins.

The public is simply advised to steer clear of algae blooms, whether we know they are blue-green or seasonal algae. Rowing, paddling, or boating across algae are bad ideas.

And although dogs may be our best friends, they often don’t differentiate between fun in the water and some nasty slimy stuff on top. Cyanobacteria produce a range of toxins that are a danger to humans and animals.

“It’s always better to be safe than sorry,” Bench said. “The lake does get tested, (but) if you see those any of those blooms, you definitely don’t want to have your dogs in the water. That can be can be up to lethal for dogs.”

Anglers will tell you seasonal algae provides shade on 100-degree days for some fish, so they’ll even work their lines alongside the blooms, hoping to get a bite.

Eating the fish from these waters - or even those with blue-green algae, doesn’t pose a threat to humans, according to the NDEE and other sources.

“The state has stocked and done a wonderful job of putting the fish back in the lake after it was drawn down (three years ago),” Bench said. There are a lot of people fishing today even though it’s this hot, and so I know people are catching fish, and we’re excited for the people to catch fish, and hopefully, they’ll be able to do it for years.”

Lake Cunningham and most other parks have links to water testing results.