Invasive species

Invasive species expand their range into Lake of the Woods

At least two invasive species expanded their ranges into the Lake of the Woods and the Rainy River basin during the summer of 2006.

Spiny waterflea has been confirmed in the Rainy River basin. These macroscopic zooplankton (they are about 1.0 cm long; although most of this length is tail) have a tendency to collect on fishing lines where they appear as a gelatinous mass with spiky protrusions and black spots. Anglers are asked to use caution, as spiny waterflea may be unintentionally transported in bait buckets, live wells or on fishing tackle. Even if the adults are dead and dried, the eggs they carry on their backs can survive drying and may hatch in new water bodies.

The existence of spiny waterflea in waters leads to a designation of infested waters. Minnesota has designated certain waters as infested because they contain specific invasive species, such as spiny waterflea, that have a high risk of spread. Regulations related to bait harvest, water transport, and draining water apply.

It is unlawful to:

  • transport prohibited invasive species on public roads;
  • transport infested water (including in livewells and bait containers) from infested waters;
  • harvest bait (minnows, frogs, crayfish, or other wild animals) from infested waters.

To view the rule describing restricted activities on infested waters, visit the following page:

For more information on Spiny Waterflea, visit the following sites:

Rusty crayfish, a native of the Ohio River Valley, has been found in the Ontario portion of Lake of the Woods since the late 1960s, but this fall was found at several locations north of Garden Island. It is highly likely that this range expansion was the result of anglers using rusty crayfish as bait. Anglers are encouraged to refrain from using live crayfish as bait, as they may be spreading this invasive. Rusty crayfish are very aggressive and will replace native crayfish species in areas they have invaded. Rusty crayfish are a lower-quality food item for fish than native crayfish and have been implicated in the loss of aquatic vegetation beds. Two other invasives species of crayfish, both Ohio River Valley natives, have also been found in the Ontario portions of Lake of the Woods.

For more information on Rusty Crayfish, visit the following site:


For more information on invasive species in Lake of the Woods, please contact:

Phil Talmage
Area Fisheries Supervisor
204 Main Street East
Baudette, MN 56623
tel.: 218-395-6032
email: Area Fisheries Supervisor

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