PIERRE, S.D. (KELO) — The state Game, Fish and Parks Department is under heavy fire from some lawmakers who want more done to slow or stop the spread of zebra mussels and other aquatic invasive species showing up in South Dakota lakes and rivers.

Top GFP officials met Tuesday and Wednesday with the Legislature’s Government Operations and Audit Committee to present information and answer questions.

The meeting came in the wake of a resolution approved by lawmakers earlier this year urging Governor Kristi Noem’s administration to “use all resources necessary to fight the spread of zebra mussels and other invasive species into our waters.”

But the department doesn’t appear to agree with another statement in that resolution that says, “Mitigation efforts to significantly slow down and even stop the spread of invasive species have proven effective in other states.”

GFP Secretary Kevin Robling filed a 12-page set of answers to questions from Representative Randy Gross, an Elkton Republican who chairs GOAC. In one key passage, Robling wrote, “There is no convincing evidence that there is a direct relationship between more (boat) inspections and fewer infestations.”

On whether zebra mussels discourage growth of walleyes — South Dakota’s state fish — Robling said various studies reach different conclusions. He said Lake Erie along the north shore of Ohio has become an “excellent” walleye fishery after zebra mussels were discovered there in the 1980s.

Regarding South Dakota, Robling said, “There has been no change in walleye or sauger growth observed for Lewis and Clark Lake, the water with the most established zebra mussel population in the state. For lakes with newer infestations, no differences in walleye growth have been observed since mussel introduction.”

Representative Gross asked Robling whether the department’s strategy of “slow the spread” should be re-evaluated, given that in the past four years, South Dakota has a dozen newly infested lakes, including Lewis & Clark, McCook, Yankton, Sharpe, Francis Case, Pickerel, Cochrane, Kampeska, Dahme Quarry, Mitchell, Pactola, Enemy Swim, Blue Dog and South Rush.

Responded Robling, “We believe we are slowing the spread and that additional waters would be infested by now without the implementation of HB1033 and outreach campaigns like Clean-Drain-Dry.”

Robling was referring to legislation passed in 2020 at the request of Governor Noem that gave the department new powers to prevent aquatic invasive species contamination in South Dakota’s public waters and declared an emergency.

Some of the challenges that GFP faced in 2022 was manpower. The department budgeted for 51 summer and seasonal positions to focus on fighting the spread this year, but left 22 vacant because of a shortage of applicants. That meant staying with 12 inspection stations rather than expanding to 15 and not adding a roving inspection team in northeastern South Dakota.

That in turn led to fewer inspections, fewer warnings and fewer citations for violations. The fine for a boater not pulling the drain plug after leaving the water is $182.50. Representative Linda Duba, a Sioux Falls Democrat, said Wednesday that GFP’s messaging needs to be more emphatic.

“It’s got to be even stronger than encourage,” Duba said. “Should we not be telling them, this is in the law and we’re going to enforce it.” Responded Jake Davis, who oversees the department’s AIS effort, “Our message has been clean, drain, dry.”

Duba asked why the department hasn’t done a study on economic impacts. Tom Kirschenmann, the department’s wildlife director, said it’s time to bring back together the department’s partnerships with other agencies and organizations.

“That’s an item that needs further discussion,” Kirschenmann told Senator Reynold Nesiba, a Sioux Falls Democrat. “I’m disappointed it wasn’t already in your budget request,” Nesiba replied, adding, “The potential negative impact is enormous, but I don’t know how big it is, because we don’t have this study.”

GFP is working on a new strategic plan for 2023, Kirschenmann said. Senator David Wheeler, a Huron Republican, said the economic impact study would be important to him in deciding what is the best use of taxpayer dollars.

Representative Chris Karr, a Sioux Falls Republican who chairs the House Appropriations Committee that oversees state government’s budget, talked about previous testimony from the department on the AIS issue. “My recollection is there’s no known way to combat the zebra mussels,” Karr said. “It’s like trying to stop the sun from rising.”

One of the questions Gross asked was what changed in the administration’s attitude regarding zebra mussels between 2020 and 2022. “As management experience with zebra mussels in South Dakota has evolved, we have focused on slowing the spread. We continue to make recommendations and decisions based on the best available data and research,” Robling answered.