Zebra mussels often elude human inspectors who search boats being hauled into and out of Minnesota lakes.

Minnesota conservation officers will get help this year in the fight against zebra mussels from three dogs specially trained to sniff out the tiny invasive species.

For the first time, the agency plans to use the dogs this spring and summer in addition to between 126 and 146 human inspectors to check boats for zebra mussels.

Zebra mussels often elude human inspectors who search boats being hauled into and out of Minnesota lakes.

On Tuesday, Labradors Brady and Digger successfully found zebra mussels hidden inside a boat trailer's taillight during a demonstration with their handlers, conservation officers with the DNR.

More than 100 Minnesota lakes, rivers and wetlands already are infested with zebra mussels. The pests clog water intake pipes, cut swimmers' feet and disrupt the ecosystem.

"The dogs are going to be able to inspect watercraft and vessels a lot faster than humans, and a lot of times more successfully because they're using their nose instead of their eyes," said Travis Muyres, one of the DNR conservation officers working with the dogs.

Muyres traveled to California this year to learn about that state's use of dogs to find zebra and quagga mussels, another invasive species. California is using more than a dozen dogs to inspect boats.

"They figured it was five to 15 times faster" to use dogs, Muyres said.

The dogs and their handlers went through five weeks of training that involved teaching the dogs to identify the scent of zebra mussels. During Tuesday's demonstration, two of the dogs took turns circling the boat and sat down when they picked up the zebra mussels' scent. They were then rewarded with a ball.

The DNR will see how the dogs perform this year and decide whether to expand the program, Minnesota Public Radio News (http://bit.ly/141xNtv) reported. The dogs also are being trained to detect wildlife such as deer to help find poachers and could also be trained to smell firearms. The DNR already has K-9 units, so Muyres said adding the zebra mussel dogs was not a big expense. One of the dogs was purchased from a breeder, and the other two came from shelters.

Finding dogs that would be a good fit was challenging, Muyres said.

"We need the right dog with the right temperament, right sociability," he said, "and then we needed the dog with the right drives. The right search drives, the right stability, the right focus. And to try to get all of those elements together in the same dog was really difficult."

The dogs and human inspectors will target high-traffic lakes, or lakes the DNR has deemed susceptible to zebra mussel infestations.