Death at the Pond

Published 10:00 am Monday, May 15, 2017

We’ve all seen that greenish, blue-green or reddish-brown scummy looking paint floating on the surface near the shoreline of a pond or lake. I hope you’ve never been tempted to dive in or take a drink out of it.  What it may be is a blue-green algae bloom. The water may be contaminated with cyanobacteria, algae-like bacteria.

Algae has been around for millions of years and is thought to be responsible for creating the earth’s atmosphere. Blue-green algae are a group of photosynthetic cyanobacteria that has chlorophyll molecules attached to it. Cyanobacteria produces toxins that are harmful to animals and people. There are different varieties that produce different types of toxins.

Lawton Stewart, a UGA Extension animal scientist, said animals affected with the liver toxins often appear weak, exhibit muscle tremors and convulsions and have bloody diarrhea. Cyanobacteria also produce neural toxins and toxins that cause skin irritation or rashes.

They can also deplete oxygen in ponds and cause foul odors and fish kills. When the bloom dies off, the blue-green algae sink to the bottom where they are digested by microbes. This digestion process pulls oxygen out of the water which may cause fish kills.

Ponds are a source of fresh water to livestock and wildlife. When conditions are just right an algae bloom can occur. The right conditions are when there is plenty of sunlight, stagnant/warm water and nutrients. As we approach another dry summer we may see the right conditions. Drought conditions cause ponds to shrink due to evaporation. As the water evaporates, the concentration of phosphorus and nitrates increase. This provides an excellent situation for toxic substances such as cyanobacteria to grow.

Using an algaecide to kill the bad algae leads to a release of more toxins which make the pond useless for more weeks and months. The best way of controlling algae blooms is prevention. Limiting nutrient flow into streams and pond prevents feeding the algae. Phosphorus is the main contaminant on inland ponds and nitrogen is the main one for estuaries along the coast line.

This means fencing off cattle from streams and ponds and allowing vegetative buffers around ponds and streams to control the runoff from fertilizer applications on nearby lawns and pastures. When algae bloom conditions are present, it might not be a good idea to spread fertilizer. Placing a pipe in the pond that feeds a water trough below the dam is one solution. All livestock should be removed from the area if a bloom is suspected.

All members of the public are invited to report any algal bloom sightings in farm ponds, neighborhood retention ponds or lakes to UGA water quality researchers through the CyanoTRACKER app, which was developed by a team led by UGA geographer Deepak Mishra.

The app, available for iPhone and Android phones, allows everyday Georgians to help track cyanobacteria blooms. Researchers can then map the topography, land use conditions and weather conditions that lead to the development of harmful algal blooms.

A water test has been developed by the UGA environmental sciences lab to test for cyanobacteria. Call the extension office for further information.

Blue-green algae can cause death to livestock and wildlife as well as being a detriment to humans. Be on the lookout this summer.

What’s going on in Extension?

Jefferson Street Market has transferred to Sim’s Pond on Bailey Road off Roanoke Rd. It begins Saturday mornings from 9:30 AM to noon.

May 15th: Beekeepers Meeting, 7 PM at the Ag Center

May 16th: Troup County Cattleman’s, Sprayer Calibration, Dinner is at 7 PM, cost $6.00, call ahead and the program begins at 7:30 PM at the Ag Center.

If you have any questions or concerns, stop by or call the office.

Brian Maddy is the ANR Agent for Troup County Extension. The Troup County Extension office is located at 114 Church Street, LaGrange, GA. 30240 (706) 883-1675. Monday – Friday/8:00 AM – 12 noon and from 1:00 PM – 5:00pm.