(08/04/16) BATON ROUGE, La. – A recent study detailing the amount of damage feral hogs are causing to water bodies in Louisiana is cause for concern, said Michael Kaller, an LSU AgCenter researcher specializing in fish and stream ecology.

The study was conducted on private lands between Alexandria and Natchitoches during summer 2015 and was based on smaller studies in 2014 in the Kisatchie National Forest and in 2002 through 2005 south of the Fort Polk Wildlife Management Area.

Water samples were taken at 40 sites and evaluated for pathogens that could be harmful to humans and other wildlife. Of the sites sampled, all exhibited some level of pathogens, Kaller said.

“The three major findings of our study show that the pathogens carried by feral hogs are dangerous to other wildlife. Illegal transport of hogs is still occurring and we need to manage collaboratively on the local, state and federal levels,” he said.

Through the use of DNA fingerprinting, scientists have found that hogs from the same family are showing up in multiple locations, causing them to believe that illegal transport is a major cause of the problem.

“We know the hog population is expanding because hogs are showing up in unexpected areas, like City Park in New Orleans,” Kaller said. “But it is very unlikely they crossed the Red River without being noticed and without some help.”

Feral hogs are known carriers of more than 30 zoonotic bacterial and viral diseases, including several pathogens that may be spread through contact with water, he said.

Feral hogs have been in Louisiana since the arrival of European settlers more than 400 years ago, but in recent years, they have become a major problem as they damage crops and urban property, become highway hazards and interfere with other wildlife, Kaller said.

“In the Great Smokey Mountains about 40 years ago, scientists determined that it’s probably not a good idea to have feral hogs sharing water bodies with other organisms,” he said. “At that time, they noticed reductions in brook trout and also a lot more bacteria in the streams.”

Kaller and his team began following up on that research about 14 years ago to see how Louisiana’s waters were being affected.

“Our study, which was conducted through a grant from the Louisiana Department of Wildlife and Fisheries, highlights how moving hogs around can exacerbate problems on your land and also your neighbor’s land,” he said.

The overarching problem is that the pigs are a nuisance to some landowners, while others see them as an opportunity for hunting and recreation, such as running them with dogs, Kaller said.

“So you have this situation where we have a natural resource issue that is multi-dimensional,” he said. “Eradication is probably never going to happen. The best case scenario is management to reduce the nuisance and pest impact.”

A 2013 study by AgCenter economist Shaun Tanger found that feral hog damage cost Louisiana farmers more the $74 million. And it’s comparable in California, Alabama and Texas.

“We’d like to do the study in different locations to see if pigs in the Florida Parishes are related to those across the Mississippi River,” Kaller said. “They shouldn’t be crossing the river, but if they are, they are probably being helped across.”

Decreasing the pig population to manageable levels will only be successful by trapping them and lethal removal, he said. “We can’t just shoot our way out of this problem.”

Olivia P. Barry, an LSU Renewable and Natural Resources student, collected water samples as part of a jointly conducted LSU AgCenter and Louisiana Wildlife and Fisheries study to determine damage feral hogs are causing to the state’s waterways. (Photo by Michael Kaller)

This lake show a properly vegetated shoreline without feral hog damage. LSU AgCenter researcher Michael Kaller, who specializes in fish and stream ecology, is studying the damage hogs are causing in lakes and streams. (Photo by Olivia P. Barry)

This shoreline exhibits feral hog damage. Where the hogs root up tubers for food, chances are healthy, beneficial vegetation will not return any time soon, said LSU AgCenter researcher Michael Kaller, who specializes in fish and stream ecology. (Photo by Olivia P. Barry)