These nonnative fish were likely never purposely introduced in North Dakota, but they got here anyway after they were stocked in Minnesota and other states in the latter 1800s as a potential new sport and food fish. The experiment, however, got out of hand and carp eventually became firmly established in many of the country’s major watersheds, including the Missouri and Red in North Dakota.

What makes carp so threatening is their destructive and competitive nature. In small lakes, they can almost completely eliminate a sport fishery. In a large bodies of water they can significantly reduce potential.

Other aquatic nuisance species can do the same thing. That’s why the North Dakota Game and Fish Department has developed new laws and increased other efforts to reduce the likelihood that any new ANS will get into the state, or any of those that currently exist will expand.

In the past, fisheries biologists and managers had asked for voluntary assistance in minimizing transfer of ANS, such as removing plants from boats and trailers when leaving a body of water.

This year, the state took another step toward limiting the potential introduction and transfer of ANS. I’ve mentioned these in a previous column but they warrant repeating.

It’s now illegal to have any vegetation dangling from your boat or other watercraft, motor, or trailer when leaving a lake. Same goes for fishing or other equipment. For instance, when you’re pulling out of the access area headed for home or another location, you must not have any aquatic vegetation with you – than includes hanging from fishing lures or hidden in bait containers.

Boats must also be drained of water in bilges and livewells, and bait containers must also be free of water. The only exception is that livewells or bait containers can hold water if they have live fish or aquatic bait in them, and the angler is enroute home from a fishing trip.

The exception for fish in livewells and aquatic bait is not allowed if the boat/vehicle is coming in from another state. All boats and other watercraft and equipment coming into North Dakota must not contain any water, and no live aquatic bait can be brought in from another state.

In addition to carp, other ANS have also made their way to North Dakota. Eurasian water milfoil has spread to the Sheyenne River near Valley City and curly leaf pondweed is choking out bays on Lake Sakakawea and backwaters of the Missouri River.

"Minnesota has zebra mussels moving westward, Iowa is fighting brittle naied and Wisconsin's well-documented VHS fish virus moving inland are just a few examples of nearby states battling issues that have not yet infested North Dakota, and our goal is to keep them from arriving," says Lynn Schlueter, Game and Fish Department aquatic nuisance species coordinator. "ANS are often not much of a concern until the infestation impacts your own water way, but the best policy is to keep ANS out of all waters, it's much cheaper in terms of money and resources to prevent them from arriving.

The mobile modern-day angler and boater can easily fish is several states in just a few days. Along the way, ANS can hitchhike in or on boats, trailers, livewells and even vehicle axles. That’s why removal of vegetation and water is now mandatory in North Dakota. Hopefully these procedures will evolve to become standard practice, not because they are laws, but because anglers and boaters embrace them as safeguards to protect the state’s aquatic resources.

An accidental introduction of ANS can cause irreparable harm. I can't stress enough the importance for all to take care.

Leier is a biologist with the Game and Fish Department. He can be reached by email: dleier@nd.gov