Are Feral Hogs A Threat to Water Quality?

Aug 1, 2016
Editor's Note: Farmers, ranchers and outdoorsmen know firsthand the damage done by the feral hog population. Across the United States, the feral hog- regardless of arguments over the actual source of these porcine pillagers- have caused plenty of damage to crops, farmland and untold damage to wild areas. Today, however, a report from Louisiana State University says they may actually be damaging water quality.

The proliferation of feral hogs in Louisiana has been well documented as have many of the negative impacts on wildlife.

But a research project by the LSU Agricultural Center's School of Renewable Natural Resources in conjunction with the Louisiana Department of Wildlife and Fisheries shows that feral hogs, recorded in all 64 parishes, are having a similarly detrimental effect on water quality on some water bodies in central Louisiana between Alexandria and Natchitoches.

The research, conducted from June 18-Sept. 1 in 2015, revealed that pathogens were extensive in sampled water bodies on private lands adjacent to Kisatchie National Forest and were regularly associated with feral hogs. The water at all 40 sites in the study contained one or more pathogens that were potentially unsafe for human or wildlife contact.

Of particular concern, of the 40 sites sampled, DNA fingerprinting positively matched 22 sites with high levels of E. coli in the water with fecal samples obtained from feral hogs both within and outside the areas sampled.

Additionally, salmonella was found at 38 of 40 sites. Both pathogens are considered harmful to both humans and wildlife. Associations were also noted between feral hog presence, heterotrophic bacteria counts (a measure of overall bacteria amount in the water) and microbes that could cause leptospirosis, yersinosis and Klebsiella pneumonia.

For wildlife, the diseases could have devastating effects. Leptospira spp. can cause kidney damage and loss of renal function in squirrels, raccoons and white-tailed deer. Leptospira has caused abortions in white-tailed deer and many other mammals.

Salmonella spp. can infect wild turkeys and other wild birds resulting in liver damage, severe diarrhea and death. Klebsiella spp. can cause sinusitis and pneumonia in wild birds and turkeys. Yersinia spp. can cause gastroenteritis in white-tailed deer and raccoons, and severe overwinter mortality has been observed in wild migratory birds.

Water quality in this region has suffered greatly on both privately and publicly owned land as the feral hog population has continued to expand, according to the report. Feral hogs are known carriers of more than 30 bacterial and viral diseases, including many pathogens than can be spread through contact with water.

"We learned through this study that there are some alarming pathogens in the water and feral hogs are implicated in the spread of these pathogens,'' said Scott Durham, LDWF Director of Species Management.

The impact to humans and wildlife in the region is particular cause for concern. Many recreational activities in these areas, including swimming, kayaking and hunting, could put humans in direct contact with these pathogens. Humans can become gravely ill from some of these diseases if misdiagnosed or untreated.

"Given the socio-cultural and economic importance of these species, loss of individuals, reduced condition and reduced fitness could have serious implications for human recreation and local economies,'' the report said.

DNA fingerprinting indicated that feral hog family groups were moving or being moved great distances in the region, up to about 30 miles at a time.

Collaborative feral hog management between local landowners and public land managers is recommended in the study.

"This study provides incredibly significant findings, illuminating the real threat to wildlife populations and human health from this feral animal's increasing presence across the state,'' Durham said. "One way to help is to never transport feral hogs. In fact, it's illegal to transport and release them. We need to develop ways to remove whole sounders (herds) of feral hogs, not just nickel and dime a few pigs at a time. You have to get rid of the whole sounder.''

To see the complete report visit:http://www.wlf.louisiana.gov/sites/default/files/pdf/document/40395-feral-hog-water-quality-report/detection_of_feral_hog_impacts_to_water_quality_wildlife.pdf

The Louisiana Department of Wildlife and Fisheries is charged with managing and protecting Louisiana's abundant natural resources. For more information, visit us a www.wlf.la.gov. To receive recreational or commercial fishing email and text alerts, signup athttp://www.wlf.la.gov/signup.