Forest-wide Spiny Water Flea Monitoring Project


Monitor the presence/absence, distribution, and abundance of spiny water flea on the Superior National Forest and provide current information to State and Federal agencies and the public in an effort to slow or stop the spread of this exotic species in northeastern Minnesota.


Spiny water flea (Bythotrephes longimanus) is an exotic zooplankton that is native to Europe and Asia. It was first introduced into the lower Great Lakes in the early 1980’s as a result of ballast water discharge from ocean going ships. This exotic zooplankton has the potential to compete with other native zooplankton and may eliminate other important species when introduced into a new lake or water body ( In 2010, the Superior National Forest conducted spiny water flea surveys in Burntside, East Pike, North Fowl, South Fowl, and John Lakes. The two Fowl lakes, North and South are border lakes between the US and Canada. The 2008 survey utilized techniques and procedures developed and used by the University of Minnesota-Duluth and Boudreau and Yan (2004). Vertical plankton tows were conducted using a 0.5 meter wide, l meter long, conical net constructed of 500 micron mesh. Reference: Boudreau, S.A. and N.D. Yan 2004. Auditing the accuracy of volunteer based surveillance program for an aquatic invader "Bythotrephes". Environmental Monitoring and Assessment 91: 17-26.


The total number of lake acres contained in the survey for the Bythotrephes longimanus is 10,459 acres. Spiny water fleas were detected in Burntside, North Fowl and South Fowl Lakes in 2010. They were not detected in East Pike and John Lakes. Currently, this exotic species occurs on the Superior National Forest in Caribou, Flour, Greenwood, Gunflint, McFarland, Pine, Little John and Crane Lakes as well as in Lake Saganaga (Minnesota Department of Natural Resources Designation of Infested Waters, October 4, 2007, 11pp). Spiny water fleas have also been documented by Voyageurs National Park in Rainy and Namakan Lakes. The Superior National Forest will continue to conduct similar surveys at new and established monitoring sites to detect new and recent.


Jason Butcher (218)626-4307


Minnesota Department of Natural Resources , University of Minnesota - Duluth , University of Minnesota - Duluth


Unhappy results!

Figure 1: Unhappy results!

Darren and Brent with equipment.