Staff from the Michigan Department of Natural Resources Charlevoix Fisheries Research Station were appreciative of the opportunity to collect important biological data on trout and salmon in Lake Michigan from tournament fishers as part of the 2008 Grand Haven Offshore Challenge on May 30-June 1, 2008. The staff wish to thank the tournament organizers, anglers, and Team Challenge for assistance and cooperation in collecting oxytetracycline (OTC) samples and coded-wire tag (CWT) returns from trout and salmon caught during the tournament. Even though the weather conditions were not optimal at the start of the tournament, the conditions improved as the tournament progressed, resulting in a total of 1,823 fish evaluated (1,282 Chinook salmon, 206 steelhead, 321 lake trout, and 14 coho salmon) for the CWT and OTC studies. For Chinook salmon, a total of 38 were sampled for CWT and 191 were sampled for OTC marks. An additional 10 steelhead and 88 lake trout were sampled for the CWT program.

Since their introduction into Lake Michigan in 1967, numbers of naturally-produced Chinook salmon smolts have been estimated in several studies and those studies have reported that natural production can range from 0 ? 7 million smolts per year. This extreme variability has led to the desire to provide more accurate estimates of natural production through a coordinated, lake-wide evaluation including the marking of all stocked Chinook salmon in Lake Michigan. Starting with the 2006 year-class, all Chinook salmon stocked in Lake Michigan are marked using OTC and the evaluation of wild production with OTC marking will continue through the 2010 year-class.

Marking trout and salmon with a CWT began in the mid-1980s and has resulted in more than 15 million marked fish since 1990. A fish with a CWT will also have the adipose fin clipped (commonly referred to as an "AD" clip) for recognition that the fish potentially contains a CWT. The CWT studies have resulted in more than 75,000 recovered tags that have provided critical information that has contributed to the ongoing successful management of important Great Lakes fish populations.