SHERIDAN (WNE) – Wyoming once again faced an increased risk from aquatic invasive species in 2023 but remains free of invasive mussels. 

Over the inspection season, Wyoming Game and Fish Department staff at watercraft check stations inspected more than 73,000 boats across the state to protect the state’s waters from invasive aquatic plants and animals.

Game and Fish personnel decontaminated 1,154 watercraft and 64 of those contained mussels – both were the highest they’ve been since the AIS program was established in 2010 by the Wyoming State Legislature. 

“This year we saw another increase in high-risk watercraft moving through Wyoming’s check stations,” said Josh Leonard, Game and Fish AIS coordinator. “But that means we’re intercepting the problematic watercraft before they enter Wyoming’s waters.”

AIS check stations are regarded as the first line of defense against invasives entering the state or being spread between Wyoming waters. Those range from invasive plants like curly pondweed — which Wyoming does have — to species the state has managed to keep out, like Asian carp and zebra or quagga mussels. Invasive mussels are one of the most destructive types of AIS, and it is very unlikely to eradicate mussels once they are established in natural water. 

The increase in high-risk inspections, necessary decontaminations and mussel boats could have been influenced by a variety of factors, but the most significant is the increase in mussel detections in states surrounding Wyoming. South Dakota, Nebraska, Colorado, Utah and Idaho all have at least one water containing zebra or quagga mussels.

As more states and waters turn up positive for AIS – particularly mussels – the threat to Wyoming continues to grow. 

The number of high-risk inspections, which are required when a watercraft is suspected of harboring AIS, hit an all-time high in 2023 with 7,415 watercraft classified as high-risk.