Aquatic Nuisance Species (ANS)
What are
Aquatic Nuisance Species?
- Nonindigenous
- aquatic plants or animals
- that
- cause harm to native and desirable species
- or
- have a negative effect on aquatic habitats, the environment, or the economy of the state.
ANS News
Zebra Mussels Discovered in Horseshoe Lake (06/2026)
The Department has confirmed invasive zebra mussels in Horseshoe Lake, Richland County, after detecting zebra mussel veligers in routine plankton tow net samples.
A subsequent follow-up sampling found additional adult mussels in the lake.
The 275-acre lake is located 5 miles southwest of Hankinson and is near Lake Elsie, which has had zebra mussels present for a number of years.
Horseshoe Lake is now considered a Class I ANS Infested waters. Emergency rules will go into effect immediately to prohibit the movement of water away from the lake, including water for transferring bait. Notices will be posted at lake access sites.
ANS Regulations and Reporting

Learn North Dakota's ANS
rules and regulations.

Discover what species are classified
as ANS in North Dakota.

Report ANS
sightings.
North Dakota High Risk Waters
The following aquatic nuisance species are known to be in at least one water body within North Dakota:
Protect North Dakota Waters from Aquatic Nuisance Species


Clean.
Remove all plants, animals and mud from all equipment.
Drain.
Empty water from baitwells, bilges, motors and other equipment.


Dry.
Dry equipment before using in a different water body.
Every Time.


