Heat and spring rains - with runoff - are being blamed for a recent outbreak of blue green algae in the Horse Creek area of Grand Lake.
On Friday, June 16, Grand River Dam Authority officials spotted the algae blooms in the Fly Creek area - an area near Horse Creek, while doing a routine aerial review of the shoreline.
Justin Alberty, corporate spokesperson for GRDA, said test of water from the area indicate the blue green algae showed a microcystin toxin levels greater than 100 micrograms per liter with estimated counts of 577,000 cells per milliliter.
Alberty said blue green algae with more than 20 micrograms per liter of microcystin and more than 100,000 cells per milliliter is considered toxic.
On Wednesday, Alberty said, GRDA officials found the algae blooms in an area just south of the Highway 85A bridge at Horse Creek and extending near the shoreline of Grand Lake State Park at Bernice.
Because of the presence of the algae blooms, Alberty said, the public is advised to take precautions to avoid bodily contact with the water in the impacted areas.
"Conditions [on the lake] are right for it," Alberty said. "We had a large outbreak during the summer of 2011. This year mirrors 2011 because we've had a lot of rain in the spring, with runoff, and when it stopped raining, it got hot and dry.
"Conditions are right for the nutrients in the water for what we are seeing now."
About Blue Green Algae
Officials with the GRDA Ecosystems Management Department tested water samples from the Fly Creek area to confirm the presence of the algae blooms.
Alberty said GRDA officials regularly check 15 GPS locations around the lake on a monthly basis for water quality. The testing increases to twice per month, from May to August, when recreational activity on Grand Lake increases.
Because the algae has been discovered on the lake, Alberty said GRDA staff will increase the frequency if the testing.
“It has to run its course. A change in the weather could effect the blooms,” Alberty said, adding that the anticipated rain this weekend may make a significant impact on the outbreak. “It will dissipate over time.”
While most of the algae is not toxic, Alberty said toxins can be produced in some of the blooms.
“We have communicated these test results to the Oklahoma Tourism and Recreation Department, the Oklahoma Department of Environmental Quality, and the Oklahoma Water Resources Board,” Alberty said. “We are closely monitoring the area and will provide updates throughout the weekend as the situation progresses.”
Impacting the lake
Alberty said it is important to remember an “overwhelming majority of the lake” is not being impacted by the outbreak.
“We don’t want people to change their weekend plans,” Alberty said. “We just want them to take adequate precautions.”
Alberty said in 2011, when the algae appeared, it looked as if someone “dumped green paint” along the shoreline. At this time, the highest concentration appears in the Fly Creek arm of Horse Creek.
“We don’t want people to panic and avoid the lake,” Alberty said. “We just want them to use precautions. We’ll continue to monitor the situation.”
Alberty said most of the blooms appear along the shoreline, however winds can carry the blooms into open water.
Grand Lake State Park - Bernice
Sherri Burris, manager of the Grand Lake State Park - Bernice, said the park remains open for business.
She said one bloom was found near the park’s boat ramp, while another has been spotted along the nature trail shoreline. No blooms have been found within the swim beach area as of presstime.
Burris said staff have posted signs warning visitors about the presence of the algae at the bathrooms and at the entrance of the park and nature center.
The signs let people know what to look for, in the event of a further outbreak.
“We’re not closing, and we are allowing campers to swim at the pool at Honey Creek State Park,” Burris said, “or we are encouraging them to get out in their boat, to deeper water.”
Burris said while the swim beach is not closed, park officials are advising people to swim at their own discretion.
“We are not covering the whole beach area,” Burris said, unlike what happened in 2011. “If people go swimming, we are advising them to take a good shower with soap after they finish.
“It’s hot, and just part of the lake issues that pop up.”
Burris said the park reopened from the spring floods a week ago. She encourages guests to visit the nature center and the hiking trail.
“There’s no reason not to come to Bernice State Park, by far,” Burris said, adding park officials are still working to determine the economic impact of the 30-plus day closure due to the heavy rains.
Persons who see a blue green algae bloom are asked to contact officials with the Oklahoma Department of Environmental Quality at 800-522-0206 or GRDA at 918-256-0911.
Health impact of the Blue Green Algae
In the advisory released by Grand River Dam Authority Spokesman Justin Alberty, officials recommend people avoid swimming or participating in water recreational activities in areas where the water is discolored or where foam, scum or mats of algae appear in the water.
The algae may resemble a “thick pea soup, green paint or bluish, brownish or reddish-green paint.”
“When [blue green algae] washes up on shore, it can form a thick mat on the beach,” Alberty said. “[It] can reproduce rapidly in water bodies with adequate amounts of sunlight and nutrients such as phosphorous and nitrogen.”
Exposure to the algae may cause skin irritation, including rashes, hives or blisters.
Alberty said inhalation of the algae may trigger asthma-like conditions or cause allergic reactions.
Inhalation of algae-impacted water could also cause stomach cramps, nausea, diarrhea or vomiting.
“Due to their body size, young children are especially susceptible to the effects of [blue green algae],” Alberty said. “It is also important to keep pets from drinking water containing BGA water.”