Gulf Coast crawfish are back on the menu in Colorado after state officials reversed a decades-long ban on importing the invasive crustaceans that was largely unheeded and unenforced.

The Colorado Parks and Wildlife Commission on Friday approved the importation of the red swamp crawfish for human consumption — though with some restrictions. Starting Jan. 1, people who want to bring the southern food staple into the state can do so with an importation license, but they cannot possess the crawfish for more than 72 hours or release them into water.

Before the change, it was illegal to import or possess the species because of concerns that the crustaceans would damage lakes and rivers if they made their way into waterways.

But the species remained easily available for purchase live or at restaurants. If caught, a violator was subject to a misdemeanor that could carry a fine of up to $5,000. Most of the people cooking and eating the mudbugs were unaware of the regulation banning them, and the ban went unenforced for years, Colorado Parks and Wildlife staff said.

“There is a huge demand on these,” Ty Petersburg, assistant chief of law enforcement programs at the agency, told the commission at an August meeting.

Consternation about the ban began in March when wildlife officials cited someone for importing the species, which led to a larger investigation into the industry.

“As a result of that case, CPW has been made aware of a significant culture in Colorado regarding social gatherings and meals surrounding crayfish boils,” a CPW memo on the issue states. “CPW law enforcement has now documented dozens of restaurants across the (Front Range) alone that hold regular crawfish boils and meal services with live imported crayfish.”

For years, Cajun restaurants sold imported crawfish, caterers put on boils for private events and individuals bought live crawfish for backyard boils. One distributor told wildlife officials that they were selling between 9,000 and 11,000 pounds of live crawfish per week during the season, from January to August.

“If you extrapolate that, we have a whole lot of these critters coming into the state — something we didn’t really realize, to be honest with you,” Petersburg said.

Despite the tons of crawfish coming into Colorado, the state has not detected a population in lakes or rivers here, said Josh Nehring, assistant aquatic section manager at CPW. However, the agency does not test specifically for the species.

“The species, if established, is capable of altering the habitat and food chain of lakes and streams,” Nehring said.

The ban was intended to keep the non-native species from being introduced to Colorado’s waters if they were used as fishing bait or released live into the water.

Red swamp crawfish are native to the Gulf of Mexico but have established invasive populations in other states, including Minnesota, New Mexico, Maine and Washington.

If introduced into Colorado waters, the species could also spread downstream to other states and communities. Several native species of crawfish live in the state east of the Continental Divide, but there are no native crawfish on the western side.

“Red swamp crayfish mature early, and have rapid growth rates, large numbers of offspring and short life spans,” a CPW memo on the species states. “They can replace indigenous crayfish by competitive exclusion and/or transmission of crayfish plague.”

A different invasive crayfish species, the rusty crayfish, is one of Colorado wildlife managers’ top invasive concerns in the state. That crayfish has been found in Colorado’s waterways since 2009 and wildlife managers believe they were introduced after anglers used them as bait.

More than 200 people weighed in on the Gulf Coast crawfish issue during the agency’s public comment process. About two-thirds of those who commented supported removing the ban. Some of those in favor of ending the ban noted that few people would pay $6 to $9 a pound for live crawfish simply to dump them in a river.

The new regulation is an attempt to balance cultural and business needs with environmental risk, Petersburg said.

Under the new rules, people who want to buy live crawfish and host their own boils must have a copy of the providers’ importation license and a receipt of purchase, Colorado Parks and Wildlife spokesman Joey Livingston said.