The Norman Transcript

May 10, 2013

The dangers of blue-green algae

The Norman Transcript

NORMAN — Despite recent cold temperatures in Cleveland County, summer is just around the corner. It is not too early to begin thinking about a trip to the lake or your favorite farm pond for boating, fishing or swimming. But what if that trip could make you sick?

For the past two years, Oklahomans have seen lakes and ponds impacted by blue-green algae (BGA) blooms that can cause illness.

BGA are present in all Oklahoma lakes and most ponds but usually remain at low levels. Problems can occur when they form visible “blooms.” Blooms tend to occur during warm periods, especially during droughts. Increased nutrient runoff near livestock concentration or other nutrient-rich areas and stagnant water increases the chance of a bloom.

BGA blooms turn water green or greenish brown. They can form floating mats and scums on the surface. BGA can produce chemicals that are toxic to humans and other animals. This is usually a concern only during blooms. Livestock and pet deaths due to BGA blooms have been reported in Oklahoma. Sen. Jim Inhofe reported becoming “deathly sick” following a swim in Grand Lake in 2011.

The toxins produced by BGA can affect you or your animals if you or they swim in, drink or even breathe in mist of contaminated water. The OK Department of Health lists the following symptoms:

· Skin exposure: rash, hives or skin blisters

· Ingestion: severe stomach cramps, nausea, diarrhea or vomiting

· Inhalation: runny eyes, runny nose, sore throat or asthma-like symptoms

Although there are no antidotes, if you experience any of these symptoms, you should seek medical help.

For information about managing aquatic vegetation in farm ponds, visit and search SRAC-360 Aquatic Weed Management.

For more information on the effects of BGA, visit,_




Heath Herje is an agriculture educator with Cleveland County Cooperative Extension service.