Wyoming conducted more than 38,600 boat inspections this summer under a program that aims to keep undesirable mussels and other invasive species out of the state's lakes and reservoirs.
Only 219 of the inspections were considered high-risk for possibly having invasive species, and 94 of those resulted in watercraft being decontaminated, Beth Bear, invasive species program coordinator for the state Game and Fish Department, told the Associated Press.
No live invasive mussels were found on any of the watercraft that were decontaminated and four were found to have dead mussels, Bear told the AP.
Non-native mussels, such as the zebra and quagga, have infected waters in several neighboring states. The mussels can damage native species and ruin fisheries.
The mussels have not been found in Wyoming and the state began the boat inspection program several years ago in hopes of keeping them out. Boats and their trailers are the most common mode of spreading mussels from one lake to another because the mussels attach themselves to the vessels.
Bear said the state monitors lakes and reservoirs that are considered to be the most likely waters where mussels might show up.
"So far, so good," she said. "We're still waiting on a few of our monitoring results, but by and large everything we've gotten back so far this year, at least for mussels, has been negative."
The state conducted 38,659 boat inspections this year from May 17 through Sept. 9 at 36 waters in Wyoming.
The inspection program costs the state about $1 million a year, Bear said. A requirement that boaters buy a special decal raised about $485,000 this year to help pay for it.
Bear said the program is worth the cost because of the millions of dollars in damage the mussels are causing in states where they are established.
"We really do feel that by spending a million dollars a year in prevention we're saving ourselves tens of millions of dollars down the road," she said.