A Texas contractor pleaded guilty to illegally planting non-native grass carp in golf course lakes and ponds to make it easier to find and retrieve golf balls.

You might say it proves that when it comes to bottom-feeders, it takes one to know one.

William Lamar Stoner, whose business is removing balls from the lakes and ponds located at golf courses around Texas, was charged with misdemeanor importation of harmful fish without a permit.

Acting on a tip from an Arkansas fish farmer, federal authorities stopped Stoner in Texarkana and arrested him with what they said was a load of 50 unsterilized Asian grass carp (Ctenopharyngodon idella), an invasive species known for its voracious appetite for marine vegetation growing on lake bottoms.

When uncontrolled, the Asian carp are widely known among fisheries biologists for the adverse effect they can have on an aquatic ecosystem. As a result, many states, including Texas, allow the importation of only sterile carp and require a special Parks and Wildlife Department permit to do so.

Because of Stoner’s illegal fish-farming efforts, U.S. Fish and Wildlife biologists were deployed to round up grass carp at five different water hazards at the Quail Creek Country Club in San Marcos, Texas. Fisheries managers were concerned that a flood on the San Marcos River would allow the fish to escape the golf course water hazards and threaten native vegetation, including endangered Texas wild rice.

Under terms of his plea agreement, Stoner will receive three years probation and a $2,000 fine and must pay $3,186.56 in restitution to Texas Parks and Wildlife and $5,000 in community restitution to the National Fish and Wildlife Foundation’s Native Plant Conservation Initiative, according to Assistant U.S. Attorney Jim Noble. He could have received up to five years in federal prison and fines up to $20,000.

“We don’t get a whole lot of grass carp cases,” Noble told the Austin American Statesman in bona-fide understatement. “I tried to find a sentence that would impress upon Stoner and the public that it’s a serious crime and there will be serious financial consequences. But I don’t think it’s necessary that Stoner be incarcerated for his offenses.”