This summer's drought conditions have made pond levels across Georgia drop and toxic algae grow. There have been four cases of cattle being killed as result of drinking infected water and many unreported cases are likely, says a University of Georgia aquaculture expert.

University of Georgia Cooperative Extension fisheries specialist Gary Burtle will discuss ways to control algae and weeds in Georgia ponds at the Agroforesty and Wildlife Field Day set for Sept. 20 on the UGA campus in Griffin, Ga.

Livestock dying, threatened

“Right now in Georgia we have a serious situation related to the drought causing algae blooms in ponds,” he said. “In ponds used to water cattle and horses, this might lead to problems with toxic algae and unsightly algae water."

“We’ve had four cows die this year and there may be more cases that we just don’t know about,” he added.

Color changes in a pond can be a clue that algae is blooming. Bright green water or water with a pea-soup-like surface scum should be avoided, and special care should be taken to keep livestock, pets and children away.

There are numerous species of common algae in the Southeast that are capable of producing toxin, but algal blooms in a pond do not always mean the water is toxic, according to scientists from the UGA Warnell School of Forestry and Natural Resources.

The blue-green algae connected to the recent cattle deaths was identified as the toxin-producing species microcystis, a cyanobacterium that produces a potent liver toxin.

At the upcoming field day, Burtle will discuss algae ecology and how to control algae in ponds. He will also talk about management of watershed ponds using the ponds at the field day site on UGA’s Westbrook Research Farm.

How to handle weeds

In a typical year, the most popular pond-related topic is aquatic weed control, so Burtle will cover this topic as well.

Ponds in Georgia are used for recreation, livestock watering, irrigation, fishing and recreation. They are also used for stormwater retention, like the ponds seen on golf courses and in subdivisions, Burtle said.

“These stormwater ponds end up developing weed problems that preclude their usage,” he said.

Unfortunately, there isn’t just one problem weed in ponds. He will discuss more than 20 aquatic weeds that grow in Georgia.

“There isn’t just one weed that’s invading the state and has earned the label of public enemy number one,” Burtle said. “We’ve got a lot of trouble weeds that are popping up due to water levels dropping. What’s a burning issue for one farmer won’t be for the next farmer down the road.”

As with agricultural crops and ornamental plants, there are chemical and nonchemical control methods available for tackling aquatic weeds. Burtle will cover both.

“I get all kinds of calls about aquatic weeds, and I usually explain what the herbicides options are," he said. "But most folks don’t like using herbicides. They want nonchemical methods."

Sportfish management will be covered, too

Jay Shelton of the UGA Warnell school will discuss sportfish management in Georgia ponds at the field day pond site with Burtle.

To register for the Sept. 20 field day and see a list of the 30 topics that will be covered, visit the website www.caes.uga.edu/events/awfd.