Water quality levels in Oso Creek are constantly at risk of high levels of bacteria, primarily because the seven-mile waterway serves as a major runoff during heavy rains and other flooding events.
But according to water quality and state wildlife officials, excessive numbers of feral swine along both Oso and Petronila Creeks in western Nueces County means E.coli contamination is on the rise in area waterways, potentially affecting the quality of life for the 500,000 residents of Nueces County who depend on the Lower Nueces River Watershed for clean drinking water.
While E.coli levels are greater in the two creeks than in the larger flow of the Nueces River, officials say every body of water on the Texas coast is being affected by the large and growing number of feral swine that add to the problem.
"When it comes to feral swine contaminating waterways, it's a two-edged sword really. In dry weather, the pigs will wallow on the banks of rivers and creeks and defecate fecal matter in the soil which works its way into the water, but when it is incredibly wet, as it has been in recent weeks, it doesn't matter much where they wallow because the runoff will carry the contaminants across the watershed and it ends up in the waterways," said JR Cantu, Farm Demonstration assistant at the Nueces County Extension office in Robstown.
Cantu has been charged with overseeing the county's new feral hog trap loan-out program for county landowners, a program designed to decrease feral swine numbers. The new traps are the latest invention in the war against feral swine, a battle that in spite of some success has so far failed to turn the tide of growing population numbers.
While there is a great range for estimated population numbers of feral swine in Texas, the general consensus is there are somewhere between 2 million to 3.5 million feral pigs in the state. Some estimates put that number even higher, but the underlying problem is, in spite of population control efforts, like scheduled hunts and modern trapping programs, feral swine numbers continue to grow.
"The Noble Research Institute estimates something like 70-percent of the feral swine population would need to be eliminated each year in order to simply maintain a steady population number, meaning that wild pigs are currently reproducing faster than we are controlling their population growth," Cantu said.
He admits that feral swine are not the only reason that E.coli levels are rising in waterways across the county, especially in Oso Creek and in Petronila Creek. Runoff from heavy rains flood across fields where livestock and other forms of wildlife deposit fecal matter. The more it rains, the greater the runoff and contamination in the county’s waterways.
But with the ever-increasing feral swine population, combined with their need to wallow in mud in wet areas across the county, their contribution to bacteria in the waterways of the county is "probably increasing significantly."
"Swine are unable to sweat so by wallowing in mud they will then scrape up against trees in an effort to remove parasites on their skin, so they are always seeking out wet areas to wallow in," Cantu added.
The county's new trap loan-out program, which finally kicked off this month after all the equipment finally arrived, utilizes the most advanced trapping system yet. Property owners who apply to participate can monitor the trap via remote camera by using their cell phones. They can even release bait when they spy activity in the areas surrounding the trap and can then trigger the trap's gate. This allows them to maximize the number of swine they can trap with the least amount of cost and effort, and with the greatest effect.
"Last week we installed one of the traps on a rancher’s property in the northern part of the county and the first night he spotted two, 300-pound plus boars roaming around the trap. The property owner installed a deer feeder inside the trap but has spotted a large sounder nearby that apparently is staying away because the boars are protective of their new feeding ground. We suggested he trap or hunt these two big boars and that might allow the larger sounder to move in so a much larger number of pigs can be trapped at the same time," Cantu noted.
Jason Ott, Agricultural County agent for Nueces County, says feral swine cause about $52 million a year in agricultural damages annually in Texas, and in addition to rooting up farm fields and pasture land, feral hogs are suspected of wildlife predation and also are instrumental in spreading diseases.
Just last week, Ott sent out a press release to area farmers and ranchers announcing the initiation of the county loan-out program. In that release he estimated an average 12 feral hogs per square mile helps to contribute to the E.coli production in area waterways.
Using Oso Creek, a seven-mile waterway, as an example: the creek banks are bordered by an estimated 352.8 acres (including both banks). An estimated 12 feral swine per acre would mean possibly 4,000-plus feral swine located within 208 feet of the creek up and down its length.
Do the math: (5,280 feet in a mile divided by 208.7 feet per one-side of a perfectly square acre equals 25.2 acres bordering each mile of the creek bank, times seven miles of creek bank equals 176.4 acres - times two creek banks equal 352.8 total acre footage borders the seven-mile creek. An acre measures approximately 43,559.86 square feet. If 12 feral swine populate each of those acres, that represents about 4,233.6 feral pigs total located within 209 feet of the creek bank. This is assuming that each acre is perfectly square, which they rarely are.)
This mathematical estimate may not represent actual numbers of swine population. Some acres have more pigs than others, and acres are rarely perfectly square. Considering pigs’ need to wallow on wet ground, more feral swine likely would populate areas with ready access to water.
Whether the number of feral swine is more or less in this example, anything close to that number of pigs per acre represents a lot of swine adjacent to the creek. Also, feral swine from more distant areas will travel to water each day.
Cantu, Ott and Texas wildlife officials agree there is an extreme need to manage the number of feral swine in the wild, and while trapping and hunting efforts undoubtedly fall short of providing a lasting solution to the problem, any and all control efforts will help.
For more information about the Nueces County trapping loan-out program, call the Nueces County Extension Office at 361.767.5223.