Skip to main content

Boreal Community Media

COOK COUNTY CONNECTIONS: Spread the word, not the species.

Apr 29, 2022 10:50AM ● By Editor

Rusty crayfish are not native to Cook County lakes. They are identified by their rusty spots on the sides of the body, and the black tips on their claws.  Submitted photos


By Amanda Weberg, AIS Coordinator for Cook County MN • April 29, 2022

 What are aquatic invasive species? At a basic level, aquatic invasive species (AIS) are living things dwelling in water that are not native to Minnesota. The impacts of AIS vary; however, they all cause problems. Some species cause damage to ecosystems, others harm the economy and human health, or all the above.  

There are many pathways for AIS to be introduced and spread. Most often AIS are unknowingly carried in or on trailered recreational watercraft and fishing equipment. Movement of boat lifts, docks, waders, and waterfowl hunting gear are also potential pathways of spread for invasive plants and invertebrates. Connected waterways can be conduits for AIS to arrive without human assistance once they have been introduced. Example: Invasive rusty crayfish have traveled from Pike Lake to Bigsby Lake to Caribou Lake and from Hungry Jack Lake to W. Bearskin Lake to Duncan Lake on their own six legs.  

Although nearly all AIS news is negative, there is hope. Cook County has few inland waterbody infestations (96% AIS free) compared to the rest of the State (92% AIS free); the AIS program actively works towards preventing AIS infestations. This is best accomplished by individuals changing their behavior to reflect sustainable AIS prevention habits. 

 Anglers and water recreation users are best reached for education through one-on-one contact. We use Minnesota’s watercraft inspection program created by the MNDNR. Friendly Cook County watercraft inspectors are stationed throughout the county at public landings during the summer. You might even interact with a sheriff’s deputy watercraft inspector on your fishing day. Law enforcement watercraft inspections are a key component to maintaining effective AIS compliance. Inspectors are there to help you learn and follow the AIS prevention methods when entering and exiting the water. They will ask you a few questions and make sure the watercraft is clear from plants and mud, and that the plugs are out. If you are saving live bait, they will remind you to empty lake water from the container and transfer to tap water brought in advance. Many inspectors store tap water in their vehicle to assist in keeping bait. Remember: It is illegal to transport lake or river water. 

With or without ice on our lakes, the Minnesota fishing opener is only a few weekends away. Preventing invasive species from invading is a never-ending process and organisms do not consider county boundaries. Those who visit or live in Cook County are fortunate to experience this wondrous part of the earth. With a few behavior changes at the water, we can all keep the Northwoods’ outdoors pristine for our children’s grandchildren. 

Remember CD3: Clean. Drain. Dry. Dispose. 

  • Clean and remove all plants, mud, and debris from boats, trailers, and gear
  • Drain all water from boat, live/bait wells, and onboard ballast tanks
  • Dry or rinse all gear and equipment thoroughly before moving to other waters
  • Dispose unwanted live bait in the trash

If you are interested in being involved in the wonderful world of AIS prevention, the AIS advisory committee is searching for new members. Contact [email protected]

Find anything weird living or growing in lakes or rivers? Soil and Water Conversation District wants to hear about it. 218-387-3648. 

Spread the word, not the species. 

Table 1. Public Waterbodies: AIS Infestations (2021)

Waterbody Name

AIS Present

Access Type

Year Confirmed

Alpine Lake (BWCA)

Purple Loosestrife

BWCA

2006

Caribou Lake (BWCA-from Pine) 

Spiny Waterflea

BWCA

2007

Caribou Lake (Lutsen)

Rusty Crayfish

Trailer Launch

2020

Chester Lake

Rainbow Smelt

Carry-In

1979

Devilfish Lake

Spiny Waterflea

Trailer Launch

2016

Devil Track Lake

Spiny Waterflea

Trailer Launch

2008

Duncan Lake (BWCA)

Rainbow Smelt, Rusty Crayfish

BWCA

1982, 2017

Flour Lake

Spiny Waterflea

Trailer Launch

2005

Gillis Lake (BWCA)

Purple Loosestrife

BWCA

2007

Gneiss Lake (BWCA)

Rainbow Smelt

BWCA

1979

Greenwood Lake

Spiny Waterflea

Trailer Launch

2005

Gull Lake

Rusty Crayfish

Trailer Launch

2002

Gunflint Lake

Spiny Waterflea, Rainbow Smelt

Trailer Launch

2007, 1979

Hungry Jack Lake

Purple Loosestrife, Rainbow Smelt, Rusty Crayfish

Trailer Launch

1992, 1971, 2002

Lake Superior

Spiny Waterflea, Rainbow Smelt

Trailer Launch

1995, 1995

Little John Lake

Spiny Waterflea, Purple Loosestrife

Trailer Launch

2005, 2009

Magnetic Lake

Rainbow Smelt

N/A

1978

McFarland Lake

Spiny Waterflea

Trailer Launch

2005

Murmur Creek

Rusty Crayfish

N/A

2020

North Fowl Lake

Spiny Waterflea

Carry-In

2010

Pigeon River

Spiny Waterflea, Rusty Crayfish

Trailer Launch

2010

Pike Lake

Rusty Crayfish

Trailer Launch

1995

Pine Lake (BWCA)

Spiny Waterflea

BWCA

2005

Red Rock Lake (BWCA)

Rainbow Smelt

BWCA

1992

Rose Lake (BWCA)

Rainbow Smelt

BWCA

1987

Royal Lake (BWCA)

Spiny Waterflea

BWCA

2010

Royal River (BWCA)

Spiny Waterflea

BWCA

2010

Sagananga Lake

Spiny Waterflea, Rainbow Smelt, Rusty Crayfish, Purple Loosestrife

Trailer Launch

2003, 1992, 2005, 2005

Sea Gull Lake

Rusty Crayfish

Trailer Launch

2005

South Fowl Lake

Spiny Waterflea

Carry-In

2010

Swamper Lake

Chinese Mystery Snail

Carry-In

2018

Thompson Lake

Chinese Mystery Snail

Carry-In

2010

Trout Lake

Spiny Waterflea, Rainbow Smelt

Trailer Launch

2013

Vista Lake (BWCA)

Purple Loosestrife

BWCA

2001

West Bearskin

Rainbow Smelt, Rusty Crayfish

Trailer Launch

1982, 2009

 

Boreal Ship Spotter - larger view here