Massive fish kill that stretched 20-miles along river outside of Atlanta being investigated

A massive fish kill stretching at least 20 miles along the Chattahoochee River in Georgia is under investigation. ​

The phenomenon – a sudden, unexpected death of fish in a short period – was first detected south of where Atlanta’s Peach Tree Creek runs into the river, environmental group Chattahoochee Riverkeeper said.

Executive director Jason Ulseth estimated that there are thousands of dead fish in the river, which forms the southern part of the Georgia-Alabama border. ​He told The Atlanta Journal-Constitution that the incident is the worst fish kill he has seen in his 20 years with the organization.

“I’ve been on the river my entire life,” he said. “I’ve never seen a fish kill this massive.”

It is not yet clear what caused the deaths, but Ulseth believes recently flooding may have played a factor.

The Riverkeeper group had detected a drop in the river’s levels of dissolved oxygen, which fish need to live, at the time of the flooding.

​Treated wastewater released by management agencies often has low-oxygen levels, and the Chattahoochee may have received a sudden influx of this low-oxygen water during the flood.

“All of the organic material of the river sucked it dry and essentially depleted all of the oxygen to where it looked like pretty much anything that swims was dead for well over 20 miles,” Ulseth said.

Rob Van Leer, a resident who lives near Peachtree Creek, was concerned about the impact the mass fish deaths would have on the local livelihoods.

“Part of our economic viability is nature and trees,” he said. “People want to walk around in nature like we’re doing today and not smell and see dead fish.”

Riverkeeper’s testing indicated that the water is not harmful to humans, but is still advising people to avoid the river between Atlanta and West Point Lake, The AJC reported.

​Ulseth stressed that the Chattahoochee River National Recreation Area, a tourist spot, is farther upstream and is unaffected.

The City of Atlanta Department of Watershed Management confirmed that an investigation was ongoing.

“The Department of Watershed Management takes incidents affecting the Chattahoochee River very seriously,” Commissioner Greg Eyerly said. “We understand the concern this fish kill has caused for residents and environmental stakeholders throughout the community.

“The investigation remains ongoing, and DWM is committed to providing accurate information and transparent updates as findings become available. Protecting the health of our waterways and the communities that depend on them remains one of our highest priorities.”

Chattahoochee Riverkeeper, Georgia Environmental Protection Division, and DWM Personnel have been deployed to assess affected areas, collect water quality samples, and coordinate with environmental agencies as part of the investigation.

At this time, the cause of the incident has not been confirmed, and no conclusions have been reached regarding contributing factors, the statement added.

A spokesperson from the department told The AJC that it does not expect the first test results from its joint investigation with the EPD and the Riverkeeper to be available until Tuesday or Wednesday.