February 1, 2002

From the Minnesota DNR 2002 Fisheries Newsletter.  Edited by Harlan Fierstine,
Area Fisheries Supervisor and Pat Rivers, Large Lake Specialist (Leech Lake).

Yellow perch sampled in gillnets in 2001 were again examined for the presence of the microsporidian parasite, Heterosporis sp.  Walleye were examined for the first time in 2001.  Fillets of infected fish have a “cooked” or “freezer burn” appearance.  The infection is only visible by inspection of the fillet.  Of the 475 perch examined, 15 or  3.2% were infected.  This is down from last year’s infection rate of 10.9%.  Although Heterosporis was confirmed in several angler-caught walleye last year, no walleye was confirmed as infected in DNR sampling this year.  Heterosporis does not infect people and infected fillets can be safely consumed.  All fish, however, should be properly cooked.

Toreduce the chance of spreading this parasite, anglers are encouraged to:

  1. Properly dispose of infected fish.  This is accomplished through being burned, buried, or placed in a landfill.  DO NOT throw known infected fish back into the lake.
  2. Thoroughly dry all equipment and boat exteriors before using other water bodies.
  3. Drain all live wells, bait buckets, and bilges.  Disinfect these areas using one cup of bleach in five gallons of water prior to moving to another water body.